tphcwg volume 4

Development of Fraction Specific Reference Doses (RfDs) and Reference Concentrations (RfCs) for Total Petroleum Hydrocarbons (TPH)

Total Petroleum Hydrocarbon Criteria Working Group Series

Volume 4


Total Petroleum Hydrocarbon Criteria Working Group Series

Volume 4

PREPARED FOR:

Chevron, British Petroleum, and theTotal Petroleum HydrocarbonCriteria Working Group

PREPARED BY:

Exxon Biomedical Sciences, Inc.:D.A. Edwards, Ph.D.M.D. Andriot, Ph.D.M.A. Amoruso, Ph.D.A.C. TummeyC.J. Bevan, Ph.D.A. Tveit, Ph.D.L.A. Hayes, M.S., MLS

EA Engineering, Science, andTechnology, Inc.:S.H. Youngren, Ph.D.

Remediation Technologies, Inc.:D.V. Nakles, Ph.D.

Amherst Scientific Publishers150 Fearing Street

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CONTENTS

PREFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

I. INTRODUCTION/BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

A. Hazard Assessment for TPH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1. Methodology for Human Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2. Ecological Considerations and Assessment of New Toxicity Data . . . . 4

B. Evaluation of Toxicity Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1. USEPA Methodology for RfD/RfC Development . . . . . . . . . . . . . . . . . 5

2. Prioritization of Toxicity Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

II. SUMMARY/CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

III. EVALUATION OF AROMATIC FRACTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

A. C5 - C6 and C>7 - C8 Aromatic Fraction . . . . . . . . . . . . . . . . . . . . . . . . . . 10

1. Oral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2. Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

B. C8 - C10, C>10 - C12, and C>12 - C16 Aromatic Fraction . . . . . . . . . . . . . . . . 12

1. Oral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

2. Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

C. C>16 - C21 and C>21 - C35 Aromatic Fraction . . . . . . . . . . . . . . . . . . . . . . . 14

1. Oral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2. Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

D. Overall Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

IV. EVALUATION OF ALIPHATIC FRACTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

A. C5 - C6 and C>7 - C8 Aliphatic Fraction . . . . . . . . . . . . . . . . . . . . . . . . . . 15

1. n-Heptane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2. Commercial Hexane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3. Other C5 - C8 Alkane/Cycloalkane Compounds . . . . . . . . . . . . . . . . . 17

4. Proposed Composition-Weighted RfD for TPH Fraction Containing C5 - C8 or C6 - C8 Aliphatics . . . . . . . . . . . . . . . . . . . . . . 19

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B. C8 - C10, C>10 - C12, and C>12 - C16 Aliphatic Fraction . . . . . . . . . . . . . . . . 21

1. Summary of Inhalation Studies on Dearomatized Petroleum Streams and JP-8 . . . . . . . . . . . . . . . . . . 22

2. Summary of Oral Gavage Studies on Petroleum Streams and JP-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

3. Summary and Conclusions for Oral RfDs and Inhalation RfCs . . . . . . 28

C. C>16 - C21 and C>21 - C35 Aliphatic Fraction . . . . . . . . . . . . . . . . . . . . . . . 29

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2. Data Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3. Rationale for RfD Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

APPENDICES

A. Literature Review (Individual Compounds) . . . . . . . . . . . . . . . . . . . . . . . 43

Attachment I - Results of Total Petroleum Hydrocarbons (TPH) Literature Search . . . . . . . . . . . . . . . . . . . . . . . . 47

Attachment II - EBSI Modified Deliverable . . . . . . . . . . . . . . . . . . . . . . 53

B. Toxicity Summaries for Both Aromatic and Aliphatic Constituents in the C4 to C22 Carbon Range . . . . . . . . . . . . . . . . . . . . . . 81

C. Review of American Petroleum Institute (API’s) Toxicity Data on Selected Refinery Streams . . . . . . . . . . . . . . . . . . . . 101

Attachment I - Composition Data on Selected Refinery Streams . . . . . 123

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PREFACE

This document is fourth in a series from the Total Petroleum HydrocarbonCriteria Working Group (TPHCWG). The Working Group was formed in 1993based on the observation that widely different clean-up requirements were beingused by states at sites that were contaminated with hydrocarbon materials such asfuels, lubricating oils, and crude oils. These requirements were usually in the formof concentrations of total petroleum hydrocarbon, otherwise known as TPH, andranged from 10 to over 10,000 milligrams of hydrocarbons per kilogram of soil.Members of the group jointly recognized that the numerical standard was notbased on a scientific assessment of human health risk and they established the fol-lowing goal for their effort:

To develop scientifically defensible information for establishing soil cleanup lev-els that are protective of human health at hydrocarbon contaminated sites.

The Working Group is guided by a steering committee consisting of representa-tives from industry, government, and academia. Some of the active participantsamong the more than 400 involved, include the Gas Research Institute, thePetroleum Environmental Research Forum, several major petroleum companiesincluding Chevron, Exxon, and Shell, the American Petroleum Institute, theAssociation of American Railroads, several state governments (i.e., Washington,Texas, Colorado, Hawaii, Louisiana, New Mexico), the U.S. EnvironmentalProtection Agency, the Department of Defense, and many consulting firms such asEA Engineering, Science and Technology.

An overlying theme to this document is the importance of exposure potentialwhen defining human health risk. The fate and transport of a chemical or mixturedefines the exposure route and, in conjunction with receptor properties, concen-trations at receptors. If fate and transport is not considered, unrealistic humanhealth risks could be calculated, resulting in misinformed decisions about siteclean-up, regulatory guidance, etc.

This document summarizes the methods used to delineate TPH into equivalentcarbon number fractions based on fate and transport considerations. The input intothe fraction method included composition data on many common fuels and petro-leum products. This information is provided in detail in Volume 2 of the WorkingGroup reports. Once the fractions were defined, fraction-specific values of relevantphysical-chemical properties were calculated based on correlations to boiling point.Companion volumes include Volume 1 which provides an overview of the com-plexities of petroleum hydrocarbon characterization and risk assessment and a dis-cussion on the analytical methods available. In addition to descriptions about gen-eral analytical methods we have also provided a summary of a proposed GC-basedanalytical method developed by the Working Group that reports hydrocarbonresults in equivalent carbon number groups or fractions.

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To complete the risk-based approach, the Working Group has also selected tox-icity criteria (e.g., Reference Doses) for each of the defined fate and transport frac-tions. The evaluation of the toxicology research database and rationale behind thetoxicity criteria selected is described in detail in Volume 4, “Development ofFraction-Specific Toxicity Criteria for Total Petroleum Hydrocarbons (TPH)” (inpreparation). The analytical method, fate and transport considerations and toxici-ty criteria are the technical elements which fit into a risk-based framework fordetermining human health based criteria at petroleum hydrocarbon contaminat-ed sites. The group selected the American Society for Testing and Materials(ASTM) Risk Based Corrective Action - RBCA framework as an example of howthese elements can be used to calculate risk-based screening levels driven by non-cancer human health risk for petroleum contaminated sites. We hope you find thisdocument to be useful in your efforts to evaluate and determine acceptable risk-based criteria at petroleum sites.

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ACKNOWLEDGMENTS

The publication of this volume of the Total Petroleum Hydrocarbon CriteriaWorking Group Methodology would not have been possible without the hard workand dedication of individuals and organizations across the public and private sec-tors. Specifically, we would like to acknowledge the following members of theTPHCWG steering committee.

Beth Albertson*, Friedman and BruyaRoger Andes and Christopher P.L. Barkan, Association of American RailroadsBruce Bauman, Roger Claff, Judith Shaw and Lorraine Twedock, APIBarbara Brooks, Hawaii Department of HealthDeborah Edwards and Joan Tell, Exxon Biomedical Sciences, Inc.John Fitzgerald, Massachusetts Department of Environmental ProtectionKathy Garland*, New Mexico EMNRDJoseph Greenblott and Bruce Peirano, US EPAJohn Gustafson, Bruce Krewinghaus, Ross MacDonald, Ileana Rhodes, ShellDevelopment CompanyKeith Hoddinott, US ArmyJim Holler, Agency for Toxic Substances and Disease RegistryPaul Kostecki and Tom Potter, University of Massachusetts, AmherstWilliam Kucharski*, GECCO Inc.Mark Laughman, Louisiana Department of Environmental QualityKatherine Kurtz, Navy Environmental Health CenterDavid Linz*, LinzTechDavid Nakles, RETECDoug Orem and Susan Youngren, EA Environmental Science and EngineeringWade Weisman*, US Air Force Armstrong Lab.Robert Wilkenfeld*, Chevron

* members of Executive Committee

The TPHCWG would like to thank the following reviewers for their helpful sug-gestions and comments: Jane Sutherlin, LADEQ; James Evans, GRI; Peter Miasek,Imperial Oil; Bill Lowery, NJDEP; Adolfo Silva, Petro Canada; Daniel Smith, USAF;and Fred Reitman, Texaco.

Additionally, we would like to commend Donna Voorhees (Menzie-Cura) andTamlyn Oliver (AEHS) for their adept assistance in editing and publication of thisdocument.

I. INTRODUCTION/BACKGROUND

The purpose of Volume 4 is to provide the basis for the development of fraction-spe-cific reference doses/concentrations (RfDs/RfCs) for total petroleum hydrocarbon(TPH). The development of fraction-specific RfDs/RfCs provides for the hazardassessment of the TPH in the TPHCWG’s risk assessment methodology (Figure 1).The selection of the most appropriate method for evaluating the risk of TPH isdescribed below. The methodology selected was termed the indicator/surrogateapproach, which is consistent with U.S. Environmental Protection Agency (USEPA)methodology and is illustrated in Figure 2 (USEPA, 1986). The indicators referredto are the single compounds within petroleum which are known to be carcinogensand which are evaluated/regulated individually (either federally or at state level).The surrogates for which RfDs/RfCs are developed are noncarcinogenic mixtures(fractions) which represent the mass of petroleum remaining after evaluation of thecarcinogenic indicators. Indicators are evaluated first because their presence (evenin relatively low concentrations) will drive a cleanup, due to their greater relativepotency. The hazard assessment for TPH fractions would be utilized where indica-tor compounds are not present or are below regulatory criteria.

A. HAZARD ASSESSMENT FOR TPH

1. Methodology for Human Health

In order to develop a human health-based method for deriving cleanup levels for petro-leum hydrocarbons in soil and groundwater, the authors surveyed the scientific litera-ture to identify methods used to assess the potential health effects of petroleum hydro-carbons. Over 30 scientific papers and reports were reviewed and the citations can befound in the General section of the reference list. Based on this review, the approach-es fit into two general categories: (1) use of toxicity data for the whole mixture or parentproduct (e.g., diesel fuel, gasoline, jet fuel, etc.) and (2) use of an indicator surrogateapproach to assess the risk and toxicity posed by the mixture. The strengths, weakness-es, and the applicability of these scientific approaches were evaluated.

Ideally, a hazard assessment should be conducted utilizing data on the mixtureto which the receptor of concern is exposed. Utilizing data on the actual mixturepresent accurately accounts for the interactive effects of all components in themixture. (Michelson and Boyce, 1993; Krewski and Thomas, 1992; WSDE, 1994;Warshawsky et al., 1993). Currently, these data are not available. The data whichare available are (1) data on some whole mixtures or parent products (e.g., gaso-line, jet fuel and mineral oil), (2) data on some individual compounds (indicators;e.g., benzene, benzo[a]pyrene) and (3) data on some fraction-specific mixtures.

Toxicity data on whole mixtures or parent products are only available for gaso-line, jet fuel, and mineral oil. Thus for other parent products (such as bunker fuel,diesel, lube oils, etc.) a whole mixture approach is not appropriate.

In addition, once in the environment the parent product separates into fractionsbased on differences in fate and transport (Volume 3, TPHCWG methodology).The mixture to which a receptor is exposed will vary with space, time, and by media.Thus, a whole mixture approach would not be appropriate for a weathered release.

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Figure 1. Risk Assessment for Petroleum Contaminated Media

Finally, there are no toxicity data on weathered fraction-specific mixtures or mix-tures of parent products (such as mixtures of diesel and gasoline). Therefore,whole mixture toxicity data are only appropriate for the hazard assessment of afresh release of a single, known product.

Toxicity data on individual compounds were evaluated (see Appendix A). Of the250 individual compounds identified in petroleum (TPHCWG Volume 2), only 95had toxicity data. Of the 95 compounds with toxicity data, only 25 have sufficientdata to develop toxicity criteria. Most of these compounds have USEPA-derivedRfDs/RfCs or slope factors. Since there are thousands of individual compoundswithin petroleum, the toxicity data on individual compounds are only appropriateto evaluate the toxicity of those specific compounds, not the toxicity of mixturessuch as TPH. The interactive effects of all the compounds present in TPH cannotbe determined by data on 25 individual compounds.

The toxicity data which are available on fraction-specific mixtures cover the aro-matic fraction (> C5 - C8) and the aliphatic fractions of TPH. Again, the fractionsof TPH referred to are those developed by the TPHCWG (Volume 3). Mixturedata on the > C9 - C16 and > C16 - C35 aromatic fractions consist of data on C8 - C11

range only. In addition, data on petroleum components > C35 are nonexistent.However, compounds above C20 are not volatile or soluble in groundwater and willremain at the release site. In addition, compounds > C35 are not likely to bebioavailable by the oral or dermal routes (Brainard and Beck, 1992).

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Figure 2. Toxicity Assessment Methods (Most technically defensible approach that can be utilized with current data.)

Based on the lack of whole product toxicity data and the interest in assessing theimpact of fate and transport on the risk of petroleum mixtures, the indicator/sur-rogate approach was chosen as the best available method for the hazard assessmentof TPH. Another consideration in the selection of the indicator/surrogateapproach was the use of this approach by two regulatory agencies: MassachusettsDepartment of Environmental Protection (MADEP) and British ColumbiaEnvironment (BCE) (MADEP, 1994; BCE, 1995). The TPHCWG method differsfrom the methods of these agencies in the way in which TPH is fractionated andthe use of toxicity data on mixtures to derive the fraction-specific RfDs/RfCs.Again, the use of mixture data is preferable since it accounts for the interaction ofcompounds within the fraction.

In summary, based on the uncertainties discussed above, a combination of dataon individual compounds (indicators) and fraction-specific mixtures (surrogates)was chosen as the TPHCWG hazard assessment methodology. This methodologyevaluates carcinogenic indicators to which the receptor is exposed individually.This is consistent with USEPA methodology for carcinogens. If these indicators arenot present or are present below levels of concern, the remaining mass of petrole-um is evaluated using fraction-specific surrogates.

The fraction-specific composition of the mixture to which the receptor isexposed is determined, and surrogate RfDs/RfCs are utilized to determine risk ordevelop cleanup goals. The use of fraction-specific surrogates accounts for theeffect of fate and transport on the whole mixture or parent product in that changesin the relative mass of each fraction at the receptor will be accounted for in the riskassessment. The assumptions (uncertainties) that remain in this method are asfollows: (1) the method assumes that the toxicity of the fraction as tested does notsignificantly change with weathering in the environment, (2) that the compositionof the fraction will not vary significantly from the surrogate tested, and (3) that theinteraction of various fractions can be assumed to be additive.

In Volume 5, a comparison of the cleanup goals derived for fresh gasoline andfresh jet fuel using the whole product and the TPHCWG method will be present-ed. For medicinal grade mineral oil, the whole product data match the TPHCWGmethod because medicinal grade mineral oil data was used to develop the > C16 -C35 RfD. MADEP conducted a similar exercise for their fractionation method withgasoline (MADEP, 1994). The two cleanup goals were within an order of magni-tude, and the level of uncertainty was deemed acceptable by MADEP.

2. Ecological Considerations and Assessment of New Toxicity Data

It should be noted that only the human health hazard has been evaluated in thisproject. Ecological receptors may or may not be protected by utilizing theRfDs/RfCs proposed in this document.

The oral and inhalation RfDs developed in this report are for the sum of all con-stituent compounds that make up each fraction of TPH. The RfDs are based onthe toxicity data for the surrogates (single compounds or, preferably, mixtures)which best represent the composition of each fraction. The RfDs have been devel-oped based on all available toxicity data for both individual compounds and mix-tures. This data was the best currently available; no new data were generated in this

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project. However, it is recognized that new data are being generated which should be eval-uated when available. In fact, new data will continue to be generated on petroleum com-pounds and mixtures and the fraction-specific RfDs should be reevaluated periodically.The RfDs/RfCs in combination with exposure concentrations are then utilized todevelop hazard quotients for each fraction. The hazard quotients are summedaccording to USEPA methodology to develop a Hazard Index for the mixture actu-ally present on site (USEPA, 1986). A description of the use of the RfDs/RfCs andfate and transport parameters (Volume 3) to evaluate the risk of TPH can be foundin Volume 5.

Both oral and inhalation (for volatile fractions) criteria have been developedapplying USEPA methods which are described below. USEPA methods were strict-ly followed unless otherwise noted.

B. EVALUATION OF TOXICITY INFORMATION

1. USEPA Methodology for RfD/RfC Development

The USEPA issued The Risk Assessment Guidelines of 1986 in which methods fordeveloping reference dose (RfD) values were given. Since then, ProposedGuidelines for Neurotoxicity; Guidelines for Developmental Toxicity RiskAssessment; and Guidelines for Reproductive Toxicity Risk Assessment have beenpublished, which also discuss the development of RfDs. In addition, the IRIS data-base provides guidance for developing RfD values in Background Document 1(Reference Dose: Use in Health Risk Assessment), last revised March 15, 1993.Information on the development and use of RfDs is also provided in RiskAssessment Guidance for Superfund Volume 1 Human Health Evaluation. Areview of the available information shows that the USEPA’s methods for determin-ing RfDs remain unchanged.

The USEPA issued Methods for Derivation of Inhalation ReferenceConcentrations and Application of Inhalation Dosimetry in which the method-ology for developing inhalation reference concentrations (RfCs) is presented.

a. Definition of the Reference Dose/Concentration (RfD/RfC)

The RfD is “an estimate (with uncertainty spanning perhaps an order of magni-tude) of daily exposure to the human population, including sensitive subgroups,that is likely to be without appreciable risk of deleterious effects during a lifetime”(USEPA, 1989).

The RfC is “an estimate (with uncertainty spanning perhaps an order of magni-tude) of continuous inhalation exposure to the human population, including sen-sitive subgroups, that is likely to be without appreciable risk of deleterious effectsduring a lifetime” (USEPA, 1994).

Both the RfD and RfC are used to evaluate potential noncarcinogenic effects ofexposure to a given compound. It is not used to evaluate carcinogenic endpoints.The RfD/RfC is operationally derived from a no-observed-adverse-effect-level(NOAEL) by application of uncertainty factors (UFs) that reflect various types ofdata sets used to estimate a reference value and by application of a modifying factor(MF) which reflects the completeness of the database.

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b. Appropriate Data for Development of an RfD/RfC

The first step in developing an RfD/RfC is to choose a critical study and determinethe NOAEL. The NOAEL is the highest dose at which no adverse effects areobserved. If a NOAEL is not available, a lowest-observed-adverse-effect-level(LOAEL) can be used; however, this adds an additional uncertainty factor into theequation.

The most appropriate source of the NOAEL for the oral RfD (or LOAEL) isfrom a chronic oral study. If there are no chronic oral data, subchronic oral datacan also be used, but this adds another level of uncertainty into the derivation ofthe RfD. In some cases, chronic and subchronic inhalation studies can be used todevelop oral RfDs when no oral data are available.

Similarly, the most appropriate studies for the development of inhalation RfCsare chronic inhalation studies. Oral studies are not used in the development ofinhalation RfCs.

Most other toxicity data (i.e., dermal, acute, or genotoxic) are not recommend-ed for use in the development of RfDs/RfCs.

c. Derivation of an RfD/RfC in This Document

i. Oral RfDThe oral RfD is calculated using the following equation:

RfD = NOAEL (or LOAEL)/(UF x MF)

where the oral RfD is expressed in mg/kg/day; the NOAEL (orLOAEL) represents a critical effect; the uncertainty factor (UF)can range from 1 to 10,000.

ii. Inhalation RfCAccording to USEPA methodology for Category 3 gases (exhibittheir toxic effects outside of the respiratory tract), the inhalationRfC is calculated using the following equations:

NOAELADJ = E x D (h/24 h) x W (days/7 days)

where the NOAELADJ is expressed in mg/m3; E is the exposurelevel; D is the number of hours exposed; and W is the number ofdays of exposure. This equation is used to convert to a continu-ous exposure.

NOAELHEC = NOAELADJ x (Hb/g)A/(Hb/g)H

where the NOAELHEC is expressed in mg/m3; NOAELADJ is calcu-lated from the equation above; (Hb/g)A/(Hb/g)H is the ratio ofblood:gas (air) partition coefficient of the chemical for the labo-ratory animal species to the human value (if these values areunknown, the default ratio is 1).

RfC = NOAELHEC (or LOAEL)/(UF x MF)

where the inhalation RfC is expressed in mg/m3; the uncertaintyfactor (UF) can range from 1 to 10,000.

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d. Uncertainty and Modifying Factors

Following are explanations of the different uncertainty factors used in the deriva-tion of RfDs/RfCs:

• Use a 10-fold factor when extrapolating from valid experimentalresults in studies using prolonged exposure to average healthyhumans. This factor is intended to account for the variation insensitivity among the members of the human population and isreferenced by USEPA as “10H”.

• Use an additional 10-fold factor when extrapolating from validresults of long term animal studies when results of humanstudies are either not available or inadequate. This factoraccounts for the uncertainty involved in extrapolating fromanimal data to humans and is referenced by USEPA as “10A”.

• Use an additional 10-fold factor when extrapolating from lessthan chronic results on experimental animals when there are nouseful long-term human data. This factor is intended to accountfor the uncertainty involved in extrapolating from less thanchronic NOAELs to chronic NOAELs and is referenced byUSEPA as “10S”.

• Use an additional 10-fold factor when deriving an RfD from aLOAEL instead of a NOAEL. This factor is intended to accountfor the uncertainty involved in extrapolating from LOAELs toNOAELs and is referenced by USEPA as “10L”.

The modifying factor is an additional uncertainty factor that has been occasion-ally applied based on the strength of the database and professional judgment. TheMF ranges from 0 to 10.

The development of benchmark doses (vs. NOAEL-based) was considered;however, the methodology for deriving a benchmark dose was believed to be lessestablished/more controversial at this time (USEPA, 1995). Thus, the NOAEL-based methodology was utilized based on current practice/level of acceptance.

2. Prioritization of Toxicity Studies

The toxicity data evaluated were any subchronic, chronic, reproductive/ develop-mental, immunotoxicity or neurotoxicity data available on the 250 individual com-pounds identified in “unweathered” petroleum (multiple products and crudes) bythe analytical section of the TPHCWG (Rhodes and Albertson, 1996). In addition,all available data on fraction-specific mixtures were identified and evaluated. In thecase of multiple studies, preference was given to the mixture data for the followingreasons. Based on studies using mixtures of benzene and toluene, polynuclear aro-matic hydrocarbons (PAHs), human data relevant to the Gulf War, etc., it is obviousthat the toxic potency of individual compounds can be influenced by the presenceof other materials. Since petroleum is a mixture, it is most appropriate to evaluateit as such. In addition, only 250 of the thousands of compounds within petroleumhave been identified. Of the 250 identified, only approximately 40 have enough

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toxicity data available to develop RfDs/RfCs and only 95 have any toxicity datawhatsoever (see Appendices A and B). It would be extremely costly to completetoxicity studies on all individual components in petroleum even if it were possibleto analytically identify them. It is the belief of the TPHCWG that what is appropri-ate to study from a risk perspective is the toxicity of fraction-specific mixtures (asdefined on the basis of environmental transport), since these are the mixtures thatreceptors will be exposed to in the environment.

In developing oral RfDs or inhalation RfCs, route to route extrapolation was min-imized; i.e., oral studies were used for oral criteria and inhalation studies for inhala-tion criteria wherever possible, based on US EPA preference (above). Finally, wheremore than one appropriate study was available, a “weight-of-evidence” approach wasapplied to develop the reference dose. The “weight-of-evidence” approach used foreach fraction is described in detail in the respective sections of this report.

II. SUMMARY/CONCLUSIONS

The fraction-specific RfDs/RfCs recommended by the TPHCWG are listed in Table1. The development of the fractions, which are based on environmental fate andtransport characteristics of the identified constituents, is described in detail in theTPHCWG Volume 3 (Gustafson et al., 1997). The technical basis for the individ-ual criteria may be found in Sections III and IV. Note that the criteria for the aro-matic fractions are at least an order of magnitude lower than the criteria for thealiphatic fractions. This is based on uncertainty as well as toxicity.

The availability of mixtures data is much greater for the aliphatic fractions thanfor the aromatic fractions; however, the toxicity data on aromatics indicate greaterpotency. Thus the aromatic fractions (for carbon numbers C9-C16 and C17-C34) arethe fractions for which more uncertainty regarding potency exists. Prioritization offurther testing should also account for the relative composition of fractionspresent. However, based on quality/quantity of toxicity data alone, uncertainty inthis methodology could be reduced to the greatest extent by testing of mixturesrepresentative of the C9-C16 and C17-C34 aromatic fractions.

Testing of fraction-specific mixtures is being considered by British ColumbiaEnvironment(for ecological receptors) and by the U. S. Air Force (for humanhealth). The Gas Research Institute and Petroleum Environmental ResearchForum (PERF) are conducting testing of hydrocarbon contaminated soils, as wellas developing fraction- specific analytical data which may soon be available to cali-brate the TPHCWG methodology. There are also new data being developed oncyclohexane, mineral oil, and n-nonane which may directly impact the fraction-spe-cific RfDs which are most appropriate for TPH.

Finally, it is appropriate to mention that the TPHCWG did not originate the ideaof utilizing fractions to evaluate the risk of TPH. The Massachusetts Departmentof Environmental Protection appears to have developed the first fractionalapproach (MADEP, 1994). In 1995, British Columbia Environment modified theMADEP approach to include fate and transport of fractions and to be specific forecological receptors of concern in the province (BCE, 1995). The TPHCWG wouldlike to thank these agencies for their leadership in this area.

8

9

Tabl

e 1.

Pr

elim

inar

y TP

HC

WG

Tox

icol

ogy

Frac

tion-

Spe

cific

Ora

l RfD

s (m

g/kg

/day

) an

d In

hala

tion

RfC

s (m

g/m

3 )

Arom

atic

Arom

atic

Alip

hati

cAl

ipha

tic

Ora

l RfD

Inha

lati

on R

fCO

ral R

fDIn

hala

tion

RfC

Car

bon

Ran

gea

(mg/

kg/d

ay)

(mg/

m3)

Cri

tica

l Eff

ect

(mg/

kg/d

ay)

(mg/

m3)

Cri

tica

l Eff

ect

Alip

hatic

0.20

0.4

Hep

atox

icity

, 5.

018

.4N

euro

toxi

city

C5

- C

6N

ephr

otox

icity

C>

6-

C8

Arom

atic

C>

7-

C8

C>

8-

C10

0.04

0.2

Dec

reas

ed0.

11.

0H

epat

ic a

ndC

>10

- C

12bo

dy w

eigh

the

mat

olog

ical

C>

12-

C16

chan

ges

C>

16-

C21

0.03

bN

AN

ephr

otox

icity

2.0

NA

Hep

atic

(fo

reig

nC

>21

- C

35bo

dy r

eact

ion)

gran

ulom

aa

Car

bon

rang

e -

actu

ally

equ

ival

ent

carb

on r

ange

(G

usta

fson

et

al.,

1997

).b

This

is t

he p

yren

e (C

16)

valu

e.

NA

= N

ot A

vaila

ble.

III. EVALUATION OF AROMATIC FRACTIONS

In this section, the oral RfDs and inhalation RfCs were evaluated along with otheravailable data for chemical constituents in each carbon fraction range. Sources ofthis information included IRIS (1996), HEAST (1995), and the EBSI literaturesearch (see Appendix A). The general approach determined by the TPHCWGwhich was used in this section involved the development of RfDs and RfCs for anentire fraction and not for a single compound. These recommended fraction- spe-cific RfDs/RfCs are based on all available data which includes information on bothindividual compounds and mixtures within the given carbon range. The fraction-specific RfD/RfC is relevant at real-world sites if any compounds which make upthe particular fraction are present.

For each aromatic fraction, the rationale for the fraction-specific RfDs andinhalation RfCs is presented below. Summaries of the data used to determinethese oral RfDs and inhalation RfCs can be found in Appendix B. One importantpoint to remember is that as new data become available for aromatic compounds,the surrogate RfDs/RfCs should be reevaluated.

A. C>7 - C8 AROMATIC FRACTION

1. Oral

According to the analytical information presented in Volume 3 (Gustafson et al.,1997), seven compounds were identified in petroleum products in this carbonrange. Oral RfDs (on IRIS) are available for six of these compounds: ethylben-zene, styrene, toluene, m-xylene, o-xylene, and p-xylene. From the EBSI literaturereview (see Appendix A), there were no other studies on the other compounds inthis fraction that could be used in the development of RfDs. Table 2 lists thesingle compound RfDs for this fraction. These values range from 0.1 to 2.0mg/kg/day. Summaries of the data used in the development of these RfDs can befound in Appendix B.

Because there are six RfDs available for the seven compounds identified in thisrange, these values can be considered to be representative of the entire fraction.After reviewing the available toxicity and compositional information for this frac-tion, it was determined that the oral RfD of 0.2 mg/kg/day is appropriate.Although ethylbenzene has a lower RfD, it is the same order of magnitude as thefraction RfD and the RfD for other constituents in the fraction (i.e., toluene). Therelative portions of ethylbenzene to other constituents in petroleum is such thatthe toluene concentration is approximately 10 times that of ethylbenzene in mostunweathered products. Also, to use a value of 2 mg/kg/day (xylenes) would notbe consistent with the other chemical-specific RfDs for the fraction. Thus, an RfDof 0.2 mg/kg/day was deemed protective. This surrogate value represents the frac-tion-specific RfD for aromatics in the C5 - C8 carbon range.

10

11

Tabl

e 2

. R

fDs/

RfC

s As

soci

ated

with

Com

poun

ds in

the

Equ

ival

ent

Car

bon

Ran

ges

Avai

labl

eAv

aila

ble

Frac

tion

Frac

tion

Equi

vale

ntC

ompo

unds

Ora

l RfD

sIn

hala

tion

RfC

sO

ral R

fDIn

hala

tion

RfC

Car

bon

Ran

ges

w/T

oxic

ity

Dat

a(m

g/kg

/day

)(m

g/m

3 )(m

g/kg

/day

)(m

g/m

3)

Tolu

ene

(C7)

0.2

0.4

Ethy

lben

zene

(C 8

)0.

11.

0C

>7

- C

8S

tyre

ne (

C 8)

0.2

1.0

0.2

0.4

Xyle

nes

(o-,

m-

,and

p-)

(C 8

)2.

0N

A

Isop

ropy

lben

zene

(C 9

)0.

040.

09N

apht

hale

ne (

C 10)

0.04

0.00

13C

>8

- C

10Ac

enap

hthe

ne (

C 12)

0.06

NA

C>

10-

C12

Bip

heny

l (C 1

2)0.

05N

AC

>12

- C

16Fl

uore

ne (

C 13)

0.04

NA

0.04

0.2

Anth

race

ne (

C 14)

0.3

NA

Fluo

rant

hene

(C 1

6)0.

04N

APy

rene

(C 1

6)0.

03N

A

C9

Arom

atic

sN

A0.

2N

apht

hale

nes/

0.03

NA

Met

hyln

apht

hale

nes

C>

16-

C21

C>

21-

C35

NA

NA

NA

0.03

NA

NA

- N

one

Avai

labl

e

2. Inhalation

There are three compounds in this fraction which currently have inhalation RfCson IRIS: toluene (0.4 mg/m3), ethylbenzene (1 mg/m3), and styrene (1 mg/m3)(Table 2). There were no additional inhalation data available on the other com-pounds in this range that could be used to develop RfCs. Again, these RfCs are feltto be representative of the entire fraction. The recommended inhalation RfC is 0.4mg/m3. This value should be protective for the entire range of compounds withinthis fraction.

B. C>8 - C10, C>10 - C12, AND C>12 - C16 AROMATIC FRACTION

1. Oral

Within this carbon range, 77 individual compounds have been identified by thefate and transport section (Tell et al., 1997). Of these identified compounds, oralRfDs have already been developed for 8 of these compounds: isopropylbenzene,acenaphthene, biphenyl, fluorene, anthracene, fluoranthene, naphthalene, andpyrene. After reviewing the information from the literature search, there were noadditional studies on individual compounds that could be used to develop addi-tional RfDs. Table 2 lists the aromatic compounds in the C9 - C16 range and theassociated oral RfDs. The RfDs range from 0.03 to 0.3 mg/ kg/day. Summaries ofthe data to develop these RfDs can be found in Appendix B.

There are also oral data available on a mixture within this carbon range: naph-thalene/ methylnaphthalenes. Data from this mixture were used to develop anRfD which was included in determining the fraction-specific RfD. This value canalso be found in Table 2. Following is a brief summary on the development of theRfD for this mixture.

Naphthalene/methylnaphthalenes1. Rats were dosed orally with 0, 300, 600, or 1000 mg/kg for 13weeks (unpublished data). Mean body weights and food con-sumption were significantly decreased in male rats at 1000 mg/kg.Histopathologic changes were centrilobular hepatocellular hyper-trophy in both sexes at all dose levels; hyperplasia and hypertro-phy of the thyroid in both sexes at all dose levels; and hyperplasiaof the urinary bladder in male rats at all dose levels and in femalerats at 300 mg/kg.

NOEL <300 mg/kg

LOAEL = 300 mg/kg/day

Using an uncertainty factor of 10,000 (10 most sensitive, 10 animalto human, 10 subchronic to chronic, 10 LOAEL to NOAEL) (seeSection B.1.c.i in section F):

RfD = 0.03 mg/kg/day

12

2. Rats were dosed orally with 0, 75, 150, or 450 mg/kg during ges-tational days 6-15 (unpublished data). At 450 mg/kg, maternalbody weight gain and food consumption were significantlydecreased during the first three days of treatment. No adversedevelopmental effects.

maternal NOEL = 150 mg/kg

developmental NOEL >450 mg/kg

These data on developmental toxicity were not used in the calcu-lation of an RfD for this fraction.

The RfD for this mixture is consistent with the RfDs for the other individualcompounds in this equivalent carbon range.

After reviewing the information on the available individual compounds and mix-tures, it was determined that the oral RfD of 0.04 mg/kg/day would be an appro-priate fraction-specific RfD for the three fractions in the C9 - C16 carbon range.Most of the available RfDs for individual compounds in this fraction are approxi-mately 0.04 mg/kg/day (of the eight available RfDs, four of the compounds haveRfDs of 0.04 mg/kg/day). The only exception is fluorene with a value of 0.3mg/kg/day. The RfDs on individual compounds represent about 10% of the com-ponents that have been identified within the fractions. Data are also available onmixtures. An RfD for the naphthalenes/methylnaphthalenes was calculated as0.03 mg/kg/day. This value supports the 0.04 mg/kg/day value. Because TPH isa mixture, emphasis needs to be placed on these available mixtures data.

2. Inhalation

Inhalation data are extremely limited in this carbon range. Inhalation RfCs havepreviously been developed for two individual compounds in this carbon range: iso-propylbenzene (C9) (0.09 mg/m3) and naphthalene (C10) (0.0013 mg/m3). Thesedata are not at all representative of the entire fraction. There were several inhala-tion studies on C9 aromatic mixtures that could be used to develop RfCs. Followingis a description of these studies and the development of the RfCs.

C9 Aromatics1. Rats were exposed to 0, 100, 500, or 1500 ppm 6 hours/day, 5days/week for 13 weeks (Douglas et al., 1993). There was reducedweight gain at 1500 ppm; no neurotoxicity.

NOEL = 1500 ppm (7362 mg/m3)

Converting to continuous exposure and using an uncertaintyfactor of 1000 (10 most sensitive, 10 animal to human, 10 sub-chronic to chronic) (See section B.1.c.ii in section I):

RfC = 1.3 mg/m3

13

2. Mice were exposed by inhalation to 0, 100, 500, or 1500 ppm 6hours/day during gestational days 6-15 (McKee et al., 1990).

maternal NOEL = 100 ppm

developmental NOEL = 100 ppm


3. Rats were exposed by inhalation to 0, 450, 900, or 1800 mg/m3 6hours/day, 5 days/week for 12 months (Clark et al., 1989). Therewere increased liver and kidney weights in male rats at 1800 mg/m3.No treatment-related histopathologic effects were observed.

NOEL = 900 mg/m3

Converting to continuous exposure and using an uncertaintyfactor of 1000 (10 most sensitive, 10 animal to human, 10 sub-chronic to chronic) (see Section B.1.c.ii of section I):

RfC = 0.2 mg/m3

The data on the C9 mixtures are more appropriate to use than the informationon individual compounds because they are more representative of TPH, which isalso a mixture. The mixtures data represent more compounds than the singlecompound information. The more conservative value, 0.2 mg/m3, was deter-mined to be representative of this entire fraction.

C. C>16 - C21 AND C>21 - C35 AROMATIC FRACTION

1. Oral

There are no previously developed RfDs for chemicals in this equivalent carbonrange. The literature search was reviewed and there were no available data todevelop an RfD. The majority of the data on compounds in this range consisted ofdermal application studies. Dermal studies are not appropriate for use in thedevelopment of oral RfDs.

After reviewing available information and determining that there are no avail-able RfDs for this group of compounds, the RfD for pyrene will be used as the sur-rogate for the fraction RfD. Pyrene is considered a conservative surrogate becauseit has a lower carbon number than any of the compounds in this fraction. Thisvalue (0.03 mg/kg/day) represents the fraction-specific RfD for the C17+ carbonrange. See Appendix B for these data.

2. Inhalation

There are no appropriate data available for the development of RfCs in this carbonrange. Also, the development of an inhalation RfC from this fraction was deter-

14

mined to be inappropriate because the compounds in this carbon range are notvolatile and inhalation will not be a relevant exposure pathway.

D. OVERALL RECOMMENDATIONS (SEE TABLE 2)

1. Use the RfD of 0.2 mg/kg/day for C5 to C8 aromatic fraction.Use the RfC of 0.4 mg/m3 for C5 to C8 aromatic fraction.

2. Use the RfD of 0.04 mg/kg/day for C9 to C16 aromatic fraction.Use the RfC of 0.2 mg/m3 for C9 to C16 aromatic fraction.

3. Use the RfD of 0.03 mg/kg/day for C17 to C35 aromatic fraction.No RfC is recommended because the fraction is not volatile.

IV. EVALUATION OF ALIPHATIC FRACTIONS

In this section, the oral RfDs and inhalation RfCs for the aliphatic fractions are devel-oped. As mentioned previously, the values for the aliphatic fractions are at least anorder of magnitude greater than those for the aromatic fractions. This is a result ofboth a difference in uncertainty and potency. The data used to develop aliphaticRfDs were derived from multiple studies on representative mixtures. Therefore,although few USEPA-derived RfDs exist for individual compounds within these frac-tions, the RfDs for the aliphatic fractions are believed to have a much higher level ofcertainty than those for the C9 - C16 and C16 - C35 aromatic fractions.

A. C5 - C6 AND C>76- C8 ALIPHATIC FRACTION

n-Hexane is the only aliphatic compound in this fraction for which the USEPA hasdeveloped an inhalation Reference Concentration (RfC). Because of its uniquetoxicity, the use of n-hexane as the basis for the fraction-specific RfD considerablyoverestimates the health risks of hydrocarbons in this fraction.

This section will present two toxicity data sets that are more representative of thepotency of the C5-C8 aliphatic fraction. The first data set is on n-heptane, which hasbeen extensively studied because it is structurally similar to n-hexane, and it can bemetabolized to a gamma diketone metabolite, which is neurotoxic. The second dataset includes toxicity studies on a solvent mixture containing hexane isomers. It is pro-posed that the health-based criteria for the C5-C8 alkane fraction be based on a per-centage basis of n-hexane in relation to the rest of the hydrocarbons in this fraction.

1. n-Heptane

Animal studies have failed to demonstrate peripheral neuropathy (the criticaleffect of n-hexane exposure) from n-heptane exposure. Frontali et al (1981)showed that n-hexane produced neurotoxic effects, including axonal degenerationafter 30 weeks of exposure, whereas n-heptane, as well as n-pentane and otherhexane isomers did not. Takeuchi et al. (1980, 1981) also found no signs of abnor-mal neurobehavioral effects in rats exposed to 3000 ppm n-heptane or n-pentane

15

12 hours/day, 7 days/week for 16 weeks. There was no evidence of peripheral neu-ropathy and motor activity was normal. Rats exposed to 400 or 3000 ppm n-heptane 6 hours/day, 5 days/week for 26 weeks showed no signs of neurotoxicity(API, 1980).

However, a possible metabolite of n-heptane, the gamma diketone 2,5-heptane-dione, has been shown to produce neurotoxic effects when administered toanimals (Katz et al., 1980; Misumi and Nagano, 1984). 2,5-Heptanedione pro-duced clinical signs of neuropathy and neuropathological alterations identical tothose produced by the gamma diketone of n-hexane (2,5-hexanedione) at dosesgreater than 1000 mg/kg (O’Donoghue and Krasavage, 1979).

Pharmacokinetic studies have attempted to quantitate the neurotoxic risk of n-heptane with that of n-hexane (Kreuzer et al., 1995). Human field studies haveshown that the presence of 2,5-hexanedione in urine is a relatively specific indica-tor of exposure to n-hexane. Urinary 2,5-hexanedione is in fact recommended byACGIH as a biological exposure index (BEI) to n-hexane (ACGIH, 1987). Todetermine the relative neurotoxic risk of n-heptane to that of n-hexane, pharma-cokinetic studies have compared the urinary levels of both gamma diketones inanimals and humans exposed to either n-hexane or n-heptane.

These studies have shown that, when rats and human volunteers were exposedto either n-hexane (up to 300 ppm) or n-heptane (up to 500 ppm), there was a 38-fold lower amount of urinary gamma-diketone in humans and rats exposed to n-heptane compared with n-hexane. Since these gamma-diketones are the metabo-lites responsible for the neurotoxic effects, the neurotoxic risk is expected to be atleast 38-times lower for n-heptane than for n-hexane.

Furthermore, 2,5-heptanedione and 2,5-hexanedione also differ in neurotoxicpotency. 2,5-Heptanedione appears to be approximately 2.5 to 5 times less potent in pro-ducing neurotoxicity than 2,5-hexanedione. In the rat, 2,5-heptanedione at dosesgreater than 1000 mg/kg/day produced signs of neuropathy and neuropathologi-cal alterations (O’Donoghue and Krasavage, 1979), whereas, 2,5-hexanedione pro-duced clinical neuropathy at doses as low as 400 mg/kg/day and altered nerve con-duction at 200 mg/kg/day (Eben et al., 1979).

Thus, n-heptane is unlikely to pose a neurotoxic hazard at exposures similar tothat of n-hexane. Even conservatively assuming that 2,5-heptanedione and 2,5-hexane-dione were equipotent as neurotoxicants, n-heptane is considered to have a neurotoxic riskthat is 38 times lower than that of n-hexane. The inhalation reference concentration(RfC) for n-hexane is 0.2 mg/m3, which is based on neurotoxic effects in humans.Assuming that the inhalation rate for a 70 kg human is 20 m3/day and absorptionis 100%, an oral reference dose (RfD) for n-hexane is 0.06 mg/kg/day. Since theRfD for n-hexane is based on neurotoxicity, then an oral reference dose of n-heptane should also be 38 times higher than that of n-hexane or 2 mg/kg/day.

An RfD of 2 mg/kg/day is a less conservative estimate of the health risks ofhydrocarbons in the C5-C8 fraction than the RfD for n-hexane. With the exceptionof n-hexane and n-heptane, C5-C8 hydrocarbons have not been shown to cause neu-rotoxicity, nor can they be metabolized to the neurotoxic gamma diketone metabo-lites. Thus, n-heptane could be considered an appropriate surrogate for the C5-C8

hydrocarbons, with the exception of n-hexane.

16

2. Commercial Hexane

A solvent containing hexane isomers has been extensively tested for health effectsas part of a USEPA mandated Test Rule under Section 4 of the Toxic SubstanceControl Act (see Table 3 summary). The hexane mixture, called commercialhexane, contained 53% n-hexane, 16% 3-methylpentane, 14% methylcyclopen-tane, 12% 2-methylpentane, 3% cyclohexane, 1% 2,3-dimethylbutane, and <1%several minor compounds. The results of the studies are summarized in Table 3.

Overall, these studies show that an inhalation exposure to a hexane mixture con-taining 53% n-hexane produces little toxicity. There were no effects on either theperipheral or central nervous system; no reproductive or developmental toxicity;and no target organ effects.

In establishing an inhalation RfC for commercial hexane mixture, the twochronic bioasssays should be considered because these studies involved lifetime expo-sure. The NOAEL for either the rat or mice chronic bioassay is 3000 ppm (10,307mg/m3). Adjusting for continuous exposure (6 hours/24 hours and 5 days/7 days),the NOAEL = 1840 mg/m3. Using an uncertainty factor of 100 (animal to humanextrapolation and intrahuman variability), the RfC is 18.4 mg/m3.

An oral reference dose for commercial hexane can be calculated using theinhalation RfC. Assuming that the inhalation rate for a 70 kg human is 20 m3/dayand absorption is 100%, then an oral RfD for commercial hexane is 5 mg/kg/day.This value is similar to the RfD derived for n-heptane. Both values are almost two ordersof magnitude higher than the RfD for n-hexane demonstrating that n-hexane isuniquely toxic and is not representative of the entire C5-C8 alkane/cycloalkane frac-tion. Finally, these data provide further evidence that the presence of other petro-leum compounds influences the toxicity of n-hexane and that mixture data shouldbe utilized to evaluate the risk of petroleum mixtures.

3. Other C5-C8 Alkane/Cycloalkane Compounds

Other C5-C8 alkane/cycloalkane hydrocarbons have been tested for subchronicand chronic toxicity. Frontali et al (1981) compared the neurotoxicity of n-hexanewith n-pentane, cyclohexane, 2-methylpentane, and 3-methylpentane. Peripheralneurotoxicity was only observed with n-hexane. This is not unexpected since onlyn-hexane can be metabolized to a gamma diketone (2,5-hexanedione) which is themetabolite responsible for the neurotoxic effects. n-Octane is the only otherhydrocarbon in the C5-C8 alkane fraction that could potentially form the gamma-diketone. However, metabolism studies were not able to detect the gamma-dike-tone in rats dosed with n-octane (Olson et al, 1986).

Cyclohexane has been tested for subchronic toxicity. Treon et al. (1943) report-ed microscopic changes in the liver and kidney of rabbits exposed 6 hours/day, 5days/week for 10 weeks to 786 ppm. No effects were observed in rabbits exposedto 434 ppm for either 10 or 26 weeks. Treon et al. (1943) also reported no treat-ment-related effects in a monkey exposed to 1243 ppm cyclohexane for 10 weeks.

New data on cyclohexane toxicity will soon be available, as it is currently part ofa USEPA mandated test rule under Section 4 of the Toxic Substances Control Act.These data may impact the RfD for this fraction and therefore should be examinedupon release.

17

18

Tabl

e 3.

C

omm

erci

al H

exan

e Te

st R

ule

Stu

dies

Toxi

city

Tes

tS

peci

esS

tudy

Des

ign

Find

ings

NO

AEL

Ref

eren

ce

Sub

chro

nic

Rat

0, 9

00,

3000

, an

d 90

00 p

pmIn

crea

sed

liver

wei

ghts

in f

emal

e 30

00 p

pmD

uffy

et

al.

(199

1)6

hour

s/da

y, 5

day

s/w

eek

for

13 w

eeks

rats

(90

00 p

pm)

Mal

e ra

t ne

phro

path

y

Sub

chro

nic

Mou

se0,

900

, 30

00,

and

9000

ppm

Incr

ease

d liv

er w

eigh

ts in

mal

e30

00 p

pmD

uffy

et

al.

(199

1)6

hour

s/da

y, 5

day

s/w

eek

for

13 w

eeks

and

fem

ale

mic

e at

900

0 pp

m

Sub

chro

nic

Rat

0, 9

00,

3000

, an

d 90

00 p

pmN

o ne

urob

ehav

iora

l or

9000

ppm

Soi

efer

et

al.

(199

1)N

euro

toxi

city

6 ho

urs/

day,

5 d

ays/

wee

k fo

r 2

year

sne

urop

atho

logi

c ef

fect

s

Chr

onic

Rat

0, 9

00,

3000

, an

d 90

00 p

pmH

isto

logi

c ev

iden

ce o

f m

ucos

al ir

ritat

ion

in

3000

ppm

Kelly

et

al.

(199

4)6

hour

s/da

y, 5

day

s/w

eek

for

2 ye

ars

nasa

l tur

bina

tes

and

lary

nx a

t 90

00 p

pm

Chr

onic

Mou

se0,

900

, 30

00,

and

9000

ppm

D

ecre

ased

sev

erity

and

inci

denc

e of

cys

tic

3000

ppm

Dau

ghtr

ey e

t al

. (1

994)

6 ho

urs/

day,

5 d

ays/

wee

k fo

r 2

year

sut

erin

e en

dom

etria

l hyp

erpl

asia

at

9000

ppm

Onc

ogen

icity

Rat

0, 9

00,

3000

, an

d 90

00 p

pmN

o ne

opla

stic

effe

cts

9000

ppm

Kelly

et

al.

(199

4)6

hour

s/da

y, 5

day

s/w

eek

for

2 ye

ars

Onc

ogen

icity

Mou

se0,

900

, 30

00,

and

9000

ppm

Li

ver

tum

ors

in f

emal

e m

ice

at 9

000

ppm

3000

ppm

Dau

ghtr

ey e

t al

. (1

994)

6 ho

urs/

day,

5 d

ays/

wee

k fo

r 2

year

s

Rep

rodu

ctiv

eR

at0,

900

, 30

00,

and

9000

ppm

R

educ

ed b

ody

wei

ght

gain

in

3000

ppm

Dau

ghtr

ey e

t al

. (1

994)

6 ho

urs/

day,

5 d

ays/

wee

k fo

r 2

gene

ratio

nsof

fspr

ing

of b

oth

gene

ratio

ns

No

adve

rse

repr

oduc

tive

effe

cts

Dev

elop

men

tal

Rat

0, 9

00,

3000

, an

d 90

00 p

pm

Mat

erna

l tox

icity

at

9000

ppm

3000

ppm

(m

ater

nal)

Keen

an e

t al

. (1

991)

6 ho

urs/

day

on

days

6-1

5 of

ges

tatio

nN

o de

velo

pmen

tal e

ffect

s90

00 p

pm (

deve

lopm

enta

l)

Dev

elop

men

tal

Mou

se0,

900

, 30

00,

and

9000

ppm

M

ater

nal t

oxic

ity a

t 90

00 p

pm30

00 p

pm (

mat

erna

l)Ke

enan

et

al.

(199

1)6

hour

s/da

y on

day

s 6-

15 o

f ge

stat

ion

No

deve

lopm

enta

l effe

cts

9000

ppm

(de

velo

pmen

tal)

In a subchronic study, rabbits were exposed by inhalation to methylcyclohexanevapor for 10 weeks. Liver and kidney effects were reported in rabbits exposed to2880 ppm, but there were no effects at 1200 ppm (Treon et al., 1943). A monkeyexposed to 370 ppm methylcyclohexane for 10 weeks showed no treatment-relatedeffects (Treon et al., 1943). A chronic study has been conducted with methylcy-clohexane (Kinkead et al., 1985). Rats, mice, hamsters, and dogs were exposed byinhalation to 0, 400, and 2000 ppm 6 hours/day, 5 days/week for 12 months. At12 months, some of the mice, rats, and hamsters were terminated; the remainingrodents were held for an additional year and the dogs for five years. There was noincrease in tumors in any of the exposed animals. The only treatment-relatedfinding was kidney nephropathy in the 2000 ppm exposed male rats.

4. Proposed Composition-Weighted RfD for TPH Fraction Containing C5-C8 or C6-C8 Aliphatics

Based on the data given above, there are two alternatives for an RfD for this fraction:

• utilize the hexane RfD(0.06 mg/kg/day) for the n-hexaneportion and the n-heptane RfD (2.0 mg/kg/day) for the remain-der of the mass.

• evaluate the hexane concentration separately. If the n-hexaneconcentration is less than 53% as found in commercial hexane,then the RfD applied should be 5mg/kg/day. If it is greater than53%, the RfD should be developed utilizing 0.06 for the n-hexane portion and 2.0 for the remaining mass(as above). Basedon the fact that only n-heptane has shown any toxicity at theselevels, both of these options are very conservative.

An evaluation of the composition of petroleum products was conducted toproduce a single value for both the C5-C8 and the C6-C8 fractions. Both fractionswere examined because the analytical group of the TPHCWG did not feel thatcurrent methodologies captured C5 reliably. It is felt that the composition of petro-leum products containing n-hexane is well known and ranges from 0.05% in somegasolines to 15.7% in Sweetened Naphtha (TPHCWG Volume 2, 1997).

The only products containing C5-C8 and therefore n-hexane are gasoline, crude,and the petroleum streams listed in Table 4. Gasoline and crude have low levels ofn-hexane. Based on an analysis of 28 samples, n-hexane in gasoline ranges from0.05 to 7.0% with a median content of 1.7% and an average content of 2.2%(PERF 94-05). The n-hexane content of two crude types were analyzed (TPHCWGVolume 2, 1996). The average concentration of n-hexane in crude was 1.3% with aminimum content of 0.7% and a maximum content of 1.8%. The content of n-hexane in petroleum refinery streams ranges from 0.06 to 15.71%; encompassingthe ranges found in gasoline and crude.

Data are available from API to evaluate the n-hexane content within the fractions(C5-C8 and C6-C8) of petroleum streams and these data are shown in Table 4. Again,this is the content within the fractions, whereas the data above are for n-hexanecontent in the whole product. Utilizing the two recommended procedures(described above) for developing RfDs for the two fractions ( C5-C8 or C6-C8) ,theaverage RfDs are 2.0 and 5.0 mg/kg/day. Based on the level of conservatism inher-

19

20

Tabl

e 4.

Co

mpo

sitio

n-W

eigh

ted

RfD

s fo

r C 5

- C

8an

d C 6

- C

8Fr

actio

ns

C5

- C

8Al

ipha

tic

Frac

tion

C6

- C

8Al

ipha

tic

Frac

tion

____

____

____

____

____

____

____

____

____

____

____

____

____

____

____

____

__

Str

eam

n-H

exan

e (w

t. %

)R

fD*

n-H

exan

e (w

t. %

)R

fD*

Ligh

t ca

taly

tical

ly c

rack

ed n

apht

ha (

API 8

1-03

)2.

42.

03.

71.

9

Ligh

t ca

taly

tical

ly c

rack

ed n

apht

ha (

API 8

1-04

)1.

82.

02.

71.

9

Sw

eete

ned

naph

tha

(API

81-

08)

16.9

1.7

26.4

1.5

Ligh

t ca

taly

tical

ly r

efor

med

nap

htha

(AP

I 81-

04)

7.8

1.8

9.7

1.8

Full

rang

e ca

taly

tical

ly r

efor

med

nap

htha

(AP

I 81-

05)

7.8

1.8

9.2

1.8

Hea

vy c

atal

ytic

ally

cra

cked

nap

htha

(AP

I 83-

18)

1.7

2.0

3.0

2.0

Hea

vy c

atal

ytic

ally

cra

cked

nap

htha

(AP

I 84-

02)

3.3

2.0

2.3

2.0

* R

fD f

or n

-hex

ane

is 0

.06

mg/

kg/d

ay;

RfD

for

non

n-h

exan

e hy

droc

arbo

ns is

2 m

g/kg

/day

ent in the RfD development and the fact that the range of n-hexane in petroleumand commercial hexane are well known, 5mg/kg/day is believed to be appropriatefor all situations with the exception of the rare release of high purity n-hexane(theonly material believed to contain greater than 53% n-hexane). This rare situationwould be easily detectable using the TPHCWG analytical methodology.

Thus, the recommended oral RfD of 5 mg/kg/day and an inhalation RfC of 18.4mg/m3 for this fraction.

B. C>8 - C10, C>10 - C12, AND C>12 - C16 ALIPHATIC FRACTION

There are minimal toxicity data available on individual components within the C9-C16 aliphatic range(Appendices A and B). The data which were utilized to developoral and inhalation criteria for this fraction were studies on JP-8 (C9-C16) andstudies on dearomatized petroleum streams which together cover the entire rangeof the fraction (Figure 3). API data on other petroleum streams were evaluated buteither the toxicity studies were not appropriate to develop criteria or the composi-tional information was inadequate to ascertain whether or not a match could bemade to this or other fractions (Appendix C).

It should also be mentioned that data are being generated (both oral and inhala-tion) by the USAF on n-nonane. These data should be evaluated when available;however, the data on petroleum streams are still considered preferable based onthe fact that these are data on mixtures rather than on an individual compound atthe low end (C9) of the fraction. MADEP had previously developed an RfD of 0.6mg/kg/day for n-nonane based on potency vs. n-hexane; no effects were seen in a

21

Figure 3. Distribution of Studies in the C9 to C16 Carbon Range

subchronic inhalation study at 10x, the hexane LOAEL concentration in a similarstudy (MADEP,1994). Finally, in selecting appropriate RfD/RfCs, the data on JP-8are given less weight than the petroleum stream data since the JP-8 has up to 20%aromatic content vs. the petroleum streams which have at most 1.5% aromatics andin most cases had less than 0.1% aromatics. The RfC selected for this fraction was1.0 mg/m3 and the RfD was 0.1 mg/kg/day.

1. Summary of Inhalation Studies on Dearomatized Petroleum Streams and JP-8

All studies were conducted according to USEPA TSCA/FIFRA or OECD guide-lines. All of the aliphatic streams showed male rat nephropathy, however, this end-point was dismissed in determining the NOAELs based on a determination by theUSEPA that it is not relevant to humans (Alden, 1986). The studies and inhalationRfCs developed are shown in Table 5.

a. Composition: C10-C11 Isoparaffinic solvent; aromatic content: <0.01%

Two studies were conducted on this product - a sub-chronic and a developmental study.

Study 1. Subchronic Toxicity Study (Phillips and Egan, 1984)

Sprague-Dawley rats were exposed by inhalation to 0, 300, or 900ppm (0, 1742, or 5226 mg/m3) for 6 hours/day, 5 days/week for 12weeks. There were questionable body weight effects at both doselevels. At study termination, increased kidney weights were observedin male rats at 300 and 900 ppm, and increased liver weights in malerats at 900 ppm. Male rat nephropathy was found at both dose levels.None of the effects observed were considered significant.

NOAEL = 900 ppm (5226 mg/m3)

Converting to continuous exposure and using an uncertaintyfactor of 1000 (10 most sensitive, 10 animal to human, 10 sub-chronic to chronic):

22

Table 5: Inhalation Studies and RfDs Developed for the C9 - C16 Fraction

Fraction Effect NOAEL RfC (mg/m3)

C10 - C11

Subchronic (Study 1) No Significant Adverse Effects 900 ppm (5226 mg/m3) 0.9Developmental (Study 2) None 900 ppm (5226 mg/m3)

C7 - C11

Subchronic (Study 3) No Significant Adverse Effects 900 ppm (5485 mg/m3) 1.0Developmental (Study 4) None 900 ppm (5485 mg/m3)

JP-8 (C9 - C16) 1.0

Subchronic (Study 5) No Significant Adverse Effects 1000 mg/m3

RfC = 0.9 mg/m3

Study 2. Developmental Toxicity Study (Mullin et al., 1990)

Rats were exposed by inhalation to 0, 300, or 900 ppm (0, 1742, or5226 mg/m3) during gestational days 6-15. No maternal or devel-opmental effects were observed.

maternal NOEL = 900 ppm (5226 mg/m3)

developmental NOEL = 900 ppm (5226 mg/m3)


b. Composition: dearomatized white spirit; C7-C11 isoparaffins/n -alkanes/napthenes;typical aromatic content: 0.1%

Two studies were conducted on this product - a subchronic and a developmentaltoxicity study.

Study 3. Subchronic Toxicity Study (Phillips and Egan, 1984)

Sprague-Dawley rats were exposed by inhalation to 0, 300, or 900ppm (0, 1828, or 5485 mg/m3) 6 hours/day, 5 days/week for 12weeks. Decreased weight gain was observed at 900 ppm. Liverand kidney weights were increased in males at 900 ppm. Male ratnephropathy was observed at all dose levels. None of the effectsobserved were considered significant.

NOAEL = 900 ppm (5485 mg/m3)

Converting to continuous exposure and using an uncertaintyfactor of 1000 (10 most sensitive, 10 animal to human, 10 sub-chronic to chronic):

RfC = 1.0 mg/m3

Study 4. Developmental Toxicity Study (unpublished data)

Sprague-Dawley rats were exposed by inhalation to 0, 300, or 900ppm (0, 1828, or 5485 mg/m3) 6 hours/day during gestationaldays 6-15. No maternal or developmental toxicity were observed.

maternal NOEL = 900 ppm (5485 mg/m3)

developmental NOEL = 900 ppm (5485 mg/m3)


23

c. JP-8 Jet Fuel

Study 5. Subchronic Toxicity Study (Mattie et al., 1991)

Rats and mice of both sexes were exposed to JP-8 vapors at 0, 500,and 1000 mg/m3 continually for 90 days. The exposure periodwas followed by a 24-month recovery period. A decrease in bodyweight (not significant) was observed in male rats (all dose levels).A statistically significant increase in basophilic foci in the liver wasobserved in male rats. There was an increased splenichematopoiesis in female rats at termination. These results werenot considered to be treatment related. The only observation inmice was an increased mortality which was due to necrotizing der-matitis. The dermatitis was a result of increased fighting amongthe animals. Overall, there was no significant toxicological effectfrom exposure to JP-8 under these test conditions.

NOAEL = 1000 mg/m3

Using an uncertainty factor of 1000 (10 most sensitive, 10 animalto human, 10 subchronic to chronic):

RfC = 1.0 mg/m3

2. Summary of Oral Gavage Studies on Petroleum Streams and JP-8

All studies are compliant with either USEPA FIFRA or OECD guidelines. None arepublished, or authorized for public release in the United States. Again, all aliphat-ic streams showed male rat nephropathy. However, this endpoint was dismissed indetermining NOAELs based on USEPA guidance (Alden, 1986). These studiesand RfDs developed are shown in Table 6.

a. Composition: dearomatized aliphatic; C9-C12 isoparaffins/n-alkanes/ naphthenes;typical aromatic content: 0.1%

Study 6. Subchronic Toxicity Study (unpublished data)

Sprague-Dawley rats were dosed orally with 0, 500, 2500, or 5000mg/kg for 90 days. A high dose recovery group was also included.Decreased body weights were observed in the male rats in the2500 and 5000 mg/kg groups. Increased food consumption in the2500 (males) and 5000 mg/kg (males and females) was observed.Increases in platelets were observed in the 500 (males), and 2500(males), and 5000 (males and females) dose groups. In male rats,increases in alanine aminotransferase were observed in the 2500and 5000 mg/kg dose groups and increases in glutamyl trans-ferase were observed in the 5000 mg/kg dose group. No changesin these parameters were observed in the female treated animals.Treatment-related microscopic changes were observed in the

24

25

Tabl

e 6:

Ora

l Stu

dies

and

RfD

s fo

r C 9

- C

16Fr

actio

n

Frac

tion

Effe

ctN

OAE

LO

ral R

fD

C 9-

C12

Sub

chro

nic

(Stu

dy 6

)R

ever

sibl

e Li

ver

Hyp

ertr

ophy

and

Hem

atol

ogic

al A

ltera

tions

LOAE

L -

50

0 m

g/kg

/day

0.1

mg/

kg/d

ay

C 10

- C

13

Sub

chro

nic

(Stu

dy 7

)R

ever

sibl

e Li

ver

Hyp

ertr

ophy

100

mg/

kg/d

ay0.

1 m

g/kg

/day

C 15

- C

18

Dev

elop

men

tal (

Stu

dy 8

)N

one

> 1

000

mg/

kg/d

ay—

C 11

- C

17

Sub

chro

nic

(Stu

dy 9

)R

ever

sibl

e Li

ver

Wei

ght

Incr

ease

100

mg/

kg/d

ay0.

1 m

g/kg

/day

JP-8

(C 9

- C

16)

Sub

chro

nic

(Stu

dy 1

0)N

o S

igni

fican

t Ad

vers

e Ef

fect

s75

0 m

g/kg

/day

0.75

mg/

kg/d

ay

n-N

onan

e (C

9)-

On

Goi

ng -

- O

n G

oing

--

On

Goi

ng -

kidneys of male rats at all dose groups; the liver (hepatocellularhypertrophy) of male/female rats at all dose groups; and thestomach (edema and hyperplasia) and/or anus of males/femalesat the 2500 and 5000 mg/kg groups. All effects were reversible in therecovery group within the 4-week recovery period.

Mechanistically, two simultaneous events seem to be occurring.(1) Male rat nephropathy. (2) The direct effect of high-dose intu-bation of a locally irritating substance. It is believed that the dosesemployed produced irritation of the gastrointestinal (GI) tract,which led to many of the other observed effects. The effectsobserved could not be dismissed and therefore a NOAEL couldnot be developed.

LOAEL = 500 mg/kg/day

The uncertainty factors that were used in the calculation were:

10 - animal to human

10 - most sensitive

10 - subchronic to chronic

5 - LOAEL to NOAEL

A value of 5 was chosen for conversion of LOAEL to NOAEL becausethe effects observed in the study were all reversible within 28 days, sothe adversity of the effects at the lowest dose level is questionable.

RfD = 0.1 mg/kg/day

b. Composition: dearomatized aliphatic; C10-C13 isoparaffins/naphthenes/n-alkanes;typical aromatic content: 0.1%


Sprague-Dawley rats were dosed orally with 0, 100, 500, or 1000mg/kg for 13 weeks. A high-dose recovery group was also includ-ed. Decreases in aspartate aminotransferase and glucose wereobserved in the 500 and 1000 mg/kg dose groups, while BUN, cre-atinine, alanine aminotransferase, and cholesterol were increasedin the treated males. In females, liver weights were increased inthe 1000 mg/kg dose groups. The liver/body weight ratio wasincreased in both the 500 and 1000 mg/kg dose groups (malesand females). Kidney weights were increased in male rats in the500 and 1000 mg/kg dose groups. Testicular weights wereincreased in the 1000 mg/kg males. Male rat nephropathy wasobserved in all dosed groups. Histopathology revealed centrilob-ular hepatocellular hypertrophy in the 500 and 1000 mg/kg dosegroups (males and females). Results from the high-dose recovery

26

group revealed all treatment-related effects were reversible within a 4-week period. The NOAEL was based on the liver effects observed.

NOAEL = 100 mg/kg/day

With an uncertainty factor of 1000 (10 most sensitive, 10 animal tohuman, 10 subchronic to chronic):

RfD = 0.1 mg/kg/day

c. Composition: dearomatized aliphatic; C15-C18; typical aromatic content 0.6-1.5%

Study 8. Developmental Toxicity Study (not published)

Sprague-Dawley rats were dosed orally with 0, 400, 800, and 1000mg/kg during gestational days 6-15. There was no significantmaternal or developmental toxicity at any of the doses tested.

NOEL >1000 mg/kg


d. Composition: C11-C17 isoparaffinic solvent; contains 22% naphthenes; typical aro-matic content <0.05%


Rats were dosed orally with 0, 100, 500, or 1000 mg/kg for 90 days.A high-dose recovery group was included. Increased liver weightswere observed at 500 and 1000 mg/kg for both males and females,and increased kidney weights for the 1000 mg/kg females. Afterthe 4-week recovery period, the differences in organ weights dis-appeared. There were no treatment-related histopathologiceffects. The NOAEL was based on liver weight changes.



RfD = 0.1 mg/kg/day

e. JP-8 Jet Fuel

Study 10. Subchronic Toxicity Study (Mattie et al., 1995)

Male rats were exposed daily by oral gavage to 0, 750, 1500, and 3000mg/kg of JP-8 for 90 days. Body weights were significantly decreasedin both mid- and high-dose groups. Glucose, total bilirubin,Aspartate aminotransferase (AST), and Alanine aminotransferase

27

(ALT) were all significantly different than control values in all threedose groups. Dose dependent irritation of the GI tract was alsoobserved. Neutrophil (elevation) and lymphocyte (depression)counts differed significantly from controls at all exposure levels. Inthe high dose group, organ/body weight ratios were significantly dif-ferent for brain, liver, kidneys, spleen, and testes. However, therewere no significant differences in individual organ weights. Male ratnephropathy was observed in all dose groups. The hematologicaland liver enzyme effects (in the absence of organ weight changes)were not considered significant. Body weight changes were dosedependent but were not significant at 750 mg/kg/day.



RfD = 0.75 mg/kg/day

3. Summary and Conclusions for Oral RfDs and Inhalation RfCs

It is important to remember that the mixtures data presented in this section coverthe entire carbon range (see Figure 3). Therefore, it is appropriate to use the mix-tures data instead of information on individual chemical compounds.

a. Inhalation

An inhalation RfC of 1.0 mg/m3 is recommended for this fraction based on inhala-tion studies for various petroleum streams and JP-8 (see Table 5). The inhalationRfCs range from 0.9 to 1.0 mg/m3 as shown in Table 5. An RfC of 1.0 mg/m3 isconsidered to be representative of this fraction. This value should be representa-tive of the entire fraction because it is based on mixtures data rather than data onindividual chemicals.

The inhalation RfC of 1.0 mg/m3 for the C9 - C16 fraction is not only protectiveof systemic toxicity, but it also appears to be protective of developmental and repro-ductive endpoints.

b. Oral

Using subchronic oral gavage data for dearomatized aliphatics (C9 - C12) and dearo-matized aliphatics (C10 - C13), RfDs of 0.1 mg/kg/ day were calculated. With theJP-8 jet fuel, an RfD of 0.75 mg/kg/day was calculated based on oral gavage data.Again, the use of this mixtures data is much more representative of the fractionthan looking at individual surrogates.

The oral RfD of 0.1 mg/kg/day for the C9 - C16 fraction is the most conservativeestimate based on the experimental data for petroleum streams and JP-8. Notethat not only is this RfD protective of systemic toxicity, but it also appears to be pro-tective of developmental and reproductive endpoints.

28

C. C>16 - C21 AND C>21 - C35 ALIPHATIC FRACTION

1. Introduction

The Total Petroleum Hydrocarbon (TPH) Criteria Workgroup has recommendedthat the toxicity criteria developed for white mineral oils be used for developingthe RfD for fractions containing aliphatic hydrocarbons C17 or higher. Whitemineral oils are a complex mixture of highly refined mineral hydrocarbons (MHC)consisting primarily of saturated paraffinic hydrocarbons (predominantlybranched chain alkanes) and naphthenic hydrocarbons (alkanes containing oneor more saturated cyclic structures). These oils are essentially pure aliphatic hydro-carbons with virtually no aromatic components or other contaminants. They areapproved by the Food and Drug Administration as direct food additives and usedextensively in foods, cosmetics, and pharmaceutical products. The abbreviationMHC is used throughout this report as a generic term to describe the range ofaliphatic hydrocarbons present in white mineral oils.

This section discusses the development of RfD values for this fraction based onthe results of a toxicity study conducted by the British Industrial BiologicalResearch Association (BIBRA) in Fischer 344 (F/344) rats as reported by Smith etal., (1996). This 90 day feeding study of several different white mineral oil samplesrepresenting different MHC sizes resulted in two distinct responses. The smaller(lower molecular weight, lower viscosity) MHC caused mesenteric lymph node his-tiocytosis and liver granulomas; the degree of response is inversely proportional tothe molecular size of the MHC. The samples containing the larger (higher mole-cular weight, higher viscosity) MHC were essentially without effect (Smith et al.,1996). It should also be noted that a chronic study in Fischer 344 rats has recentlybeen completed in Japan. Although unpublished, the preliminary results of thisstudy support the conclusions developed below.

2. Data Summary

In the BIBRA study, male and female F/344 rats were administered a range ofwhite mineral oils mixed in the diet at doses of 20, 200, 2,000 and 20,000 ppm for90 days. The data will be expressed as the composite average daily intakes (approx-imately 2, 20, 200, and 2,000 mg/kg/day, respectively). This study utilized sevensamples which represented a full range of white mineral oils. The refining historyand physical properties of the oils are shown in Table 7.

Rats exposed to the lower molecular weight oils (average molecular weight 320- 420) had histological changes in the liver and the mesenteric lymph nodes.Mesenteric lymph node histiocytosis was noted at doses of 20 mg/kg/day or higher,whereas liver granulomas were only noted at the 2,000 mg/kg/day dose in ratsexposed to lower molecular weight oils (N10A, N15H, P15H, N70A and N70H).The incidence and severity of the effects were inversely related to the molecularweight of the MHC. Females were more sensitive than males.

Rats fed up to 2,000 mg/kg/day of the higher molecular weight white mineraloils (BIBRA samples P70H and P100H) showed no effect on body weight, clinicalsigns, or mortality No treatment related toxicity or histopathological effects wereseen in these animals.

29

30

Tabl

e 7.

Te

st M

ater

ials

and

Phy

sica

l Pro

pert

ies

of W

hite

Min

eral

Oils

Use

d in

BIB

RA

Stu

dya

Aver

age

Aver

age

Car

bon

Sam

ple

Cru

de T

ype

Ref

inin

g M

etho

dVi

scos

ity

(cS

t) 4

0 0C

Mol

ecul

ar W

eigh

tN

umbe

r D

istr

ibut

ion

N10

AN

apht

heni

cAc

id T

reat

men

t13

.332

0C 1

5-30

N15

HN

apht

heni

cH

ydro

gena

tion

16.6

330

C 17-

30

P15H

Para

ffini

cH

ydro

gena

tion

15.0

350

C 18-

30

N70

AN

apht

heni

cAc

id T

reat

men

t76

.441

0C 2

1-35

N70

HN

apht

heni

cH

ydro

gena

tion

68.0

420

C 22-

37

P70H

Para

ffini

cH

ydro

gena

tion

69.5

485

C 27-

43

P100

HPa

raffi

nic

Hyd

roge

natio

n99

.851

0C 2

8-45

Sam

ple

abbr

evia

tion

s:N

=N

apht

heni

c, P

= P

araf

finic

, A

= A

cid

Trea

ted,

H =

Hyd

roge

nate

d, N

umbe

r (1

0,15

,70,

100

) =

App

roxi

mat

e vi

scos

ity (

cSt)

at

40o C

.

aD

ata

wer

e ob

tain

ed f

rom

Sm

ith e

t al

. (1

996)

.

3. Rationale for RfD Values

a. Determination of Two Distinct Responses

The effects of MHC in F/344 rats appear to be inversely related to molecularweight (MW). The average MWs of the white mineral oils used in the BIBRA studyare shown in Table 7. Administration of the low molecular weight oils resulted ingranulomatous effects in F/344 rats, with greater responses seen with the lowestMW oils. Essentially no effects were noted with the high molecular weight oils.Based on these differences in toxicological responses, two separate RfD values arewarranted. Based on the low molecular weight oil data, a lower RfD is recom-mended for the lower molecular weight TPH aliphatic fractions (C17-34, averageMW 240-480), whereas a higher RfD value is recommended for the higher molec-ular weight TPH aliphatic fraction (C>34, average MW >480) based on the high mol-ecular weight oils which showed no effect.

The lack of effects seen with the high molecular weight MHC is consistent withstudies showing essentially no absorption for alkanes above C32 (Albro andFishbein, 1970). In this study, the retention of selected aliphatic hydrocarbons wasmeasured in rats after intragastric administration. An inverse relationship with ahigh correlation coefficient (0.96) was found between molecular size and reten-tion of the aliphatic hydrocarbons. The largest molecule used in this study wassqualane (C30), 96-100% of the oral dose was recovered unchanged in the feces,indicating essentially no absorption.

b. Determination of No Observed Adverse Effect Level (NOAEL)

The critical effect used to determine RfDs for TPH aliphatic fractions C>17 is livergranuloma formation based on the MHC data. As shown in Table 8, the lowestobserved adverse effect level (LOAEL) for the low molecular weight oils was 2,000mg/kg/day; the no observed adverse effect level (NOAEL) for these oils was 200mg/kg/day. The NOAEL for the high molecular weight oils was 2,000 mg/kg/day.

Although mesenteric lymph node histiocytosis was noted at lower doses, thisfinding was not considered to be an adverse effect because it is a normal adaptiveresponse to the ingestion of foreign material (Schuurman et al., 1994). Thenormal physiological function of the mesenteric lymph node is to filter foreignmaterial from the lymph. Previous work by Albro and Fishbein (1970) showed that

31

Table 8. Liver Granuloma Response in the BIBRA Studya

Category Sample ID NOAEL (mg/kg/day) LOAEL (mg/kg/day)

Low Molecular Weight N10A, N15H, 200 2,000(C17-34) P15H, N70A, N70H

High Molecular Weight P70H, P100H 2,000 ndb

(C>34)

NOAEL = No observed adverse effect levelLOAEL = Lowest observed adverse effect levela Data obtained from Smith et al., (Smith et al., 1996).b No response was noted at the highest concentration used in the study (2,000 mg/kg/day).

aliphatic hydrocarbons are absorbed by the small intestine and enter the lymph.Mesenteric lymph nodes draining the gut- associated lymphoid tissue normallyshow sinus-histiocytosis (Shuurman et al., 1994). Mesenteric lymph node histiocy-tosis is, therefore, not considered an adverse effect in the F/344 rat.

c. Justification of Safety Factors

The RfDs for TPH aliphatic fractions C>17 were calculated using a safety factor of100. This factor takes into account animal to human extrapolation (a factor of 3),individual susceptibility (a factor of 10), and subchronic to chronic extrapolation(a factor of 3). Normally a safety factor of 1000 would be used; however, the overallweight of evidence on MHC justifies a lower uncertainty factor in this case for thereasons described below:

i. Extensive human exposure to both natural dietary oils andMHC does not indicate any clinical effects. Although MHC-induced lipid granulomas have been observed in humantissues, these findings are considered to be clinically unimpor-tant and are pathologically distinct from the lesions noted inF/344 rats. Human lipid granulomas are characterized asbenign, circumscribed lesions containing mineral oil in thecenter, without evidence of inflammation, fibrosis, or signifi-cant liver dysfunction (Wanless and Geddie, 1985). In contrast,the liver granulomas in F/344 rats are characterized as reactivewith associated inflammation and occasional parenchymal cellnecrosis (Smith et al., 1996). This evidence supports a loweruncertainty factor for animal to human extrapolation

ii. F/344 rats appear to be a uniquely sensitive strain of rats. Theinflammatory effects noted in F/344 rats were not seen indogs, mice or different strains of rats (Long-Evans or SpragueDawley) fed comparable doses of similar MHC (Firriolo et al.,1995; Smith et al., 1995). In addition, historical chronicstudies of MHC at doses of up to 10% in the diet of SpragueDawley rats were without clinical or histological effects(Shubik et al., 1962). Thus, the F/344 rat appears to have apredisposition for granulomatous effects. When compared toother rat strains (Wistar, Sprague Dawley), the F/344 rat hada higher incidence of spontaneous granulomas in the mesen-teric lymph nodes (Ward et al., 1993). A review of theNational Toxicology Program (NTP) chronic and subchronicstudies also revealed a highly variable incidence of sponta-neous liver granulomas and mesenteric lymph node histiocy-tosis in untreated control F/344 rats with the incidencehigher in females than in males. These studies suggest thatthe F/344 rat is predisposed to the development of inflam-matory granulomatous lesions (Miller et al., 1996), therebyproviding further support for a lower uncertainty factor foranimal to human extrapolation.

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iii Although F/344 rats have a predisposition for inflammatorygranulomatous responses, these effects do not appear toprogress to tumors nor alter lifetime, body weight or healthstatus of the rats. For example, in a recent Japanese study,F/344 rats administered 5% MHC in the diet for 24 monthsdisplayed mesenteric lymph node histiocytosis, but no differ-ences in body weight, survival, or tumor incidence were notedin any of these animals compared to controls (Takahashi,1996). NTP conducted studies on chlorinated paraffins (C23,43% Cl), comprised of linear saturated hydrocarbons with amolecular size similar to the low molecular weight oils used inthe BIBRA study (Bucher et al., 1987). F/344 rats receivedchlorinated paraffin by gavage at doses up to 900 mg/kg(females) and 3,750 mg/kg (males) 5 days a week for up to 2years. F/344 rats had effects similar to those seen with MHC,i.e. mesenteric lymph node histiocytosis and liver granulomas.Interestingly, there were no treatment related effects onF/344 rat survival, body weight, tumor incidence, or healthstatus. These results suggest that the granulomatous lesionsnoted in F/344 rats exposed for 90 days to MHC, will notresult in any adverse clinical effects following chronic expo-sure, and justify a lower uncertainty factor for subchronic tochronic extrapolation.

d. Calculation of RfD

The RfD for TPH aliphatic fractions containing C>17 was calculated according toUSEPA guidelines in which the NOAEL, based on the critical effect, is divided byan appropriate safety factor.

i. RfD for C17-34 MHC

The RfD for TPH fractions containing aliphatic fractions ofC17-34 is 2 mg/kg/day based on the NOAEL for low molecularweight oils for liver granulomas (200 mg/kg/day) and a safetyfactor of 100.

ii. RfD for C>34 MHC

The RfD for TPH fractions containing aliphatic fractions C>34

is 20 mg/kg/day based on the NOAEL for high molecularweight oils for liver granulomas (2,000 mg/kg/day) and asafety factor of 100.

33

iii. Conclusion

As shown in Table 9, the RfD for TPH fractions containing analiphatic carbon range of C17 - C34 MHC is 2 mg/kg/day; forfractions containing aliphatic fractions C>34 , the RfD is 20mg/kg/day. The RfDs were based on the results of the BIBRAstudy (Smith et al., 1996) using liver granulomas as the criti-cal effect. The use of these RfD values for determining clean-up levels for TPH aliphatic fractions C>17 should provide anadequate margin of safety to protect human health.

34

Table 9. Development of Oral RfDs for TPH Aliphatic Fractions C≥ 17

TPH Aliphatic Fraction NOAELa (mg/kg/day) LOAELa (mg/kg/day) r RfD (mg/kg/day)

C17-34 200 2,000 100 2

C>34 2,000 ndb 100 20

RfD = Reference DoseTPH = Total Petroleum HydrocarbonsNOAEL = No observed adverse effect levelLOAEL = Lowest observed adverse effect levela Based on the liver granuloma response noted in Smith et al., (1996).b No response was noted at the highest concentration used in the study (2,000 mg/kg/day).

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Schuurman, H.J., Kuper, C.F., and Vos, J.G.. 1994. Histopathology of the immune system as a tool toassess immunotoxicity. Toxicology 86:187-212.

Shubik, P., Saffiotto, U., Lijinsky, G., Pietra, G., Rappoport, H., Toth, B., Raha, C.R., Feldman, R., andRamahi, H. 1962. Studies of the toxicity of petroleum axes. Toxicol. Appl. Pharmacol. 4(Supp):1-62.

Smith, J.H., Bird, M.G., Lewis, S.C., Freeman, J.J., Hogan, C.K., and Scala, R.A. 1995. Subchronicfeeding study of four white mineral oils in dogs and rats. Drug and Chem. Tox. 18:83-103.

Smith, J.H., Mallett, A.K., Priston, R.A.J., Brantom, P.G., Worrell, N.R., Sexsmith, C., and Simpson, B.J.1996. Ninety-day feeding study in Fischer 344 rats of highly refined petroleum-derived food-gradewhite oils and waxes. Toxicol. Pathol. 24:214-230.

Stefanski, S.A., Elwell, M.R., and Stomberg, P.C. 1990. Ch. 22 Spleen, lymph nodes, and thymus. In:Pathology of the Rat (eds. Boorman, G.A., Eustis, S.L., Elwell, M.R., Montgomery, C.A., andMacKenzie, W.F.) Academic Press, San Diego p. 385.

Takahashi M. 1996. Carcinogenicity study of white mineral oil. Presented at the European ToxicologyForum March 28, 1996. Oxford U.K. p. 573.

Wanless, I.R. and Geddie, W.R. 1985. Mineral oil lipogranulomata in liver and spleen. Arch. Pathol.Lab Med. 109:283-286.

Ward, J.M., Uno, H., and Frith, C.H. 1993. Immunohistochemistry and morphology of reactive lesions inlymph nodes and spleen of rats and mice. Toxicol. Pathol. 21:199-205

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APPENDIX A

Literature Review(Individual Compounds)

OBJECTIVE

A literature review was conducted by EA Engineering, Science, and Technologies,Inc. (EA) in order to identify toxicity data and toxicity factors for approximately250 chemical constituents of petroleum products. This information will be used toselect surrogates for specific petroleum hydrocarbon fractions. Exxon BiomedicalSciences, Inc. (EBSI) reviewed the EA work product and identified surrogates forwhich additional toxicity data were available. A second literature review, conduct-ed at EBSI, captures these data.

SEARCH STRATEGY - EA

EA identified USEPA toxicity factors including reference dose and slope factors atnational and regional levels, and state-assigned toxicity values. An on-line searchof the National Library of Medicine (NLM) electronic bibliography files,Hazardous Substances Data Base (HSDB) and Registry of Toxic Effects of ChemicalSubstances (RTECS) was subsequently conducted to identify toxicity data for mate-rials that were not assigned a federal or state toxicity factor. EA supplied a detailedexplanation of this process in a document entitled “Summary of Work for Project6a of the TPH Criteria Work Group.”

The EA deliverable is a compendium of toxicity factors and toxicity data, pre-sented in spreadsheet format, accompanied with a list of references.

SEARCH STRATEGY - EBSI

EBSI modified the EA deliverable to include additional toxicity data and omittedstudies that were less than 4 weeks in duration. Studies of this length are not appro-priate for determining a No Observable Effect Level (NOAEL). One exception,however, was the addition of developmental studies to the EA deliverable. TheUSEPAs approach to determining a reference dose (RfD) or reference concentra-tion (RfC) is based on the NOAEL. Ideally, a NOAEL is derived from a chronicstudy. Modifying factors are then applied to the NOAEL to account for variabilityand uncertainties in the data. When no chronic study is available, an RfD or RfCmay be calculated from a suitable subchronic study.

To identify additional toxicology studies, an on-line search of the following bib-liographic and summary databases was conducted: TOXLINE (1965+); MEDLINE(1963+); EMBASE (1974+); American Petroleum Institute Literature (APILIT)(1963+); RTECS; HSDB; IRIS; and the Chemical Carcinogenesis ResearchInformation Service (CCRIS) database. A detailed explanation of EBSIs searchstrategy is provided in Attachment I.

Fourteen constituents in the C3 to C15 range were identified as having potentialdata and were subject to an on-line search. These constituents are listed in Table1 of Attachment I. The literature search focused on subchronic, chronic and devel-opmental studies from oral or inhalation routes of exposure. Acute studies wereexcluded. A second search for studies for surrogates in the C13 to C26 range fol-lowed. Forty-eight chemicals (Table 2 of Attachment I) were nominated. However,no significant “new” studies were found for this carbon range.

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DELIVERABLE

The modified EA deliverable is provided in Attachment II. In addition, a toxicitysummary for the added studies can be found in Appendix B, entitled “ToxicitySummaries for Aromatic and Aliphatic Constituents in the C4 to C22 Carbon Range.”

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ATTACHMENT I

Results of Total Petroleum Hydrocarbons (TPH) Literature Search

INTEROFFICE CORRESPONDENCE DATE: February 28, 1996

TO: REFERENCE:

FROM: SUBJECT:

Results of Total Petroleum Hydrocarbons (TPH) Literature Search

LITERATURE SEARCH CONDUCTED TO IDENTIFY TPH SURROGATES

This literature search supported a project to revise methods for determining safelevels of Total Petroleum Hydrocarbons (TPH). There is much variation on whatspecific hydrocarbons should be used as surrogates. This project was to determinesurrogate substances for carbon ranges, e.g., n-hexane for C6, and calculate refer-ence doses for these surrogates. The TPH Criteria Workgroup had a search doneon 250 chemicals identified as being possible surrogates and provided a list withdose, species, route, duration, estimated tox factor, critical effect and a citation.Info Services was asked to locate additional tox studies, especially chronic and sub-chronic, that could be used to calculate the reference doses. We also did a searchto verify chemical and physical constants provided by the Workgroup.

ON-LINE AND MANUAL SOURCES SEARCHED

On-line Sources

Toxline (1965 - present)

Medline (1963 - present)

Excerpta Medica (1974 - present)

American Petroleum Institute Literature - APILIT (1963 - present)

Registry of Toxic Effects of Chemical Substances (RTECS)

Hazardous Substances Data Bank (HSDB)

EPA’s Integrated Risk Information Service (IRIS)

Chemical Carcinogenesis Research Info. Service (CCRIS)

Chemical Information System (CIS) Databases:

ENVIROFATE (Environmental Fate)

MANUAL SOURCES

Verschueren, K. (1983). Handbook of Environmental Data on Organic Chemicals,2nd Edition. New York: Van Nostrand Reinhold.

Mackay, D., Shiu, W.Y. and Ma, K.C. (1992). Illustrated Handbook of Physical-Chemical Properties and Environmental Fate for Organic Chemicals. BocaRaton: Lewis Publishers.

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LITERATURE SEARCH FOR TOX DATA FOCUSED ON C3-C15 CHEMICALS AND PNAS

The original TPH Criteria Workgroup list had identified 254 chemicals (C3-C26)as possible TPH surrogates and found useful tox studies on about 65 materials. Wescanned the C3-C15 compounds and identified 14 materials on which it wasbelieved there were additional tox studies. Table 1 lists the chemicals we tagged.The search focused on oral and dermal chronic and subchronic studies and, anyinhalation, genetox, reprotox and carcinogenicity studies were included also.Acute studies were excluded. The printouts were arranged by chemical.

There was too much information on biphenyl to do a reasonable search in thetime allotted. We provided the summary printouts (RTECS, HSDB, etc.) andwould fill in missing endpoint gaps later.

For trimethylbenzenes, the search was limited to the past 5 years. However, itwas noticed that the API C9 aromatic hydrocarbons studies were omitted from theWorkgroup list. These studies were done in the mid to late 1980s and would nothave been captured by my search. Therefore, for trimethylbenzenes only, Iexpanded the time range on the search to include the API studies.

In the set of printouts for methylcyclopentane (MCP), you will also find refer-ences on commercial hexane. Since MCP is a component of commercial hexane,I included the published studies and TSCA submissions on commercial hexane inthe search for this material since they may be relevant.

No materials were identified in the C15-C26 range. Most of those materials arePNAs with a few long chain alkanes and cyclic compounds. The ATSDR on PNAsissued in 1994 is a good review of PNA tox. However, I was requested to search forany studies in the 1994 to present time range, and the search was broadened toinclude C13-C26. Table 2 lists the 48 chemicals searched for this part. Note that Idid not search for references on benz(a)pyrene (BAP). A scan of the hits (over2,000) turned up primarily BAP as a positive control in skin-painting studies ofnon-PNA materials.

I found very few significant studies on these compounds from 1994 to present.This is not surprising. The carcinogenicity of PNAs is fairly well established and sincethere is no commercial use for these materials, there is little justification for theirstudy. I found very few studies on the alkanes and cyclics on the list. The availabletox studies on long chain alkanes are old (pre 1980) and are mostly acute studiessince many of these substances were evaluated as possible cosmetic ingredients.

ADDITIONAL SOURCES FOR CHEMICAL/PHYSICAL CONSTANTS WERE LOCATED

Joan Tell provided a list of about 125 chemicals with chemical/physical con-stants such as solubility, Henry’s law constant, etc. The request was to look for pub-lished values for the materials to verify the values provided by the Workgroup andto indicate if the values found were experimental (measured) or theoretical (cal-culated). Beth Meriwether, who did the bulk of this part, did not use the refer-ences cited by the Workgroup in their list since this request was for additionalsources. However, I do recommend that you view the references used by theWorkgroup as an additional source.

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The main source used for this search was Mackay, et.al. (Illustrated Handbookof Physical-Chemical Properties and Environmental Fate for Organic Chemicals).Beth found a good portion of the values in this book. The highlight of this sourceis that it is a compendium of published values and gives parameters and references.Beth used Verschueren, HSDB, and ENVIROFATE to fill in the data gaps.

She did not find all the values, especially diffusion coefficients, and I went on-line to look for other possible, mainly on-line, sources. The numeric property data-bases on STN are very expensive and a search could cost a considerable sum. JoanTell and I discussed this and she decided to use what she had. Variability in diffu-sion coefficients is not significant and she felt reasonably confident with the valuesgiven by the Workgroup.

SEARCH RESULTS WERE ORGANIZED BY CHEMICAL

This writeup covers all the searches done in support of this project. Most of thetox studies printouts were given to you although Deb did direct me to give aportion of the C15-C26 printouts to Michelle. Joan has the chemical and physicalconstants portion of the search.

Please feel free to contact me if you have any questions or need additionalinformation.

/lah

cc: M.D. AndriotD.A. EdwardsA.C. HolladayE.J. MeriwetherJ.G. Tell

49

50

Table A-1. List of 14 Chemicals (C3-C15)isopropylbenzene

n-butylbenzene

p-cymene

1-pentene

methylcyclohexane

n-propylbenzene

t-butylbenzene

tetralin

cyclohexene

biphenyl

trimethylbenzene (all isomers)

diethylbenzene (all isomers)

durene

methylcyclopentane

Table A-2. Additional Materials (C13-C26)

1-t-butyl-3,4,5-trimethylbenzene2,6-dimethylundecanefluorenen-heptylbenzeneheptylcyclohexane4-methylbiphenyln-tridecanetridecene1,4,5-trimethylnaphthaleneanthracene4,4’-dimethylbiphenyl1-methylfluorenen-octylbenzenephenanthrenen-tetradecane

9-methylanthracene2-methylanthracene1-methylphenanthrenen-pentadecane9,10-dimethylanthracene2-ethylanthracenefluroanthenen-hexadecane1-phenylnaphthalene

pyrene1,2-benzofluorene2,3-benzofluorenen-heptadecane1-methylpyrenebenz(a)anthracenechrysenen-octadecanetriphenylene5-methylchrysenen-nonadecanebenz(b)fluroanthenebenz(k)fluoranthenebenz(a)pyrene (not searched)benz(e)pyrene

n-eicosaneperylenebenz(ghi)perylenen-heneicosane3-methylcholanthrene1,2,5,6-dibenzanthracenepicenecoronenen-hexacosane

ATTACHMENT II

EBSI MODIFIED DELIVERABLE

APPENDIX B

Toxicity Summaries for Both Aromatic and Aliphatic Constituents in the C4 to C22 Carbon Range

2-BUTENE (C4)

Male and female Wistar rats were exposed to 2-butene (42.4% cis-2-butene; 55.3%trans-2-butene) in a combined repeat dose and reproductive/developmental toxici-ty study. Animals were exposed at nominal concentrations of 0, 2500 and 5000 ppm2-butene, 6 hours/day, 7 days/week. Actual concentrations were 0, 2476 and 5009ppm or 0, 5.7 and 11.5 g/m3, respectively. Exposure of mated females ended aftertreatment on day 19 of gestation. A significant decrease in body weight was noted inthe high dose females during premating weeks 0 to 2, and one day after parturition.Food consumption was decreased for this group in the first pre-mate week. In males,total white blood cell count and lymphocyte number were significantly increased.However, this increase did not follow a dose relationship and was within historicalcontrol values. Plasma Ca-levels were significantly decreased in males at 11.5 g/m3.No reproductive effects were observed in the parental animals. No effects wereobserved on the number of pups born, sex ratio or viability index. The NOAEL was5.7 g/m3 for the P generation and > 11.5 g/m3 for the F1 generation.

Koten-Vermeulen, J.E.M.v., Plassche, E.J. v.d. 1992. SIDS Dossier on the HPV P1 Chemical: 2-Butene.RIVM, Rijksinstituut Voor Volksgezondheid en Milieuhygiene National Inst.

CYCLOPENTENE (C5) - 99.8%

Wistar II rats (10/sex/group) were exposed to 0, 870 or 8110 ppm cyclopentenevapor, 6 hours/day, 5 days/week for 3 weeks. Body weight gain was decreased infemales at 8110 ppm. Appearance, behavior and gross evaluations were unre-markable.

Wistar II rats (10/sex/group) exposed to 0, 112, 317 or 1139 ppm cyclopentenevapor, 6 hours/day, 5 days/week for 12 weeks tolerated test concentrations withoutany detectable effects. Animals were observed daily and weighed weekly.Hematology, clinical chemistry and urine analyses were unremarkable, as wereanimal appearance and behavior. No macroscopic or histological changes wereobserved. The NOEL was 1139 ppm for this study.

Kimmerle G., Thyssen, J. 1975. Acute, subacute and subchronic inhalation toxicity of cyclopentene. Int. Arch. Arbeitsmed. 34:177-184.

TOLUENE (C7)

An oral RfD of 0.2 mg/kg/day for toluene is currently on IRIS. This value is basedon a subchronic oral gavage study in rats (NTP, 1989). Groups of 10rats/sex/group were administered toluene in corn oil at levels of 0, 312, 625, 1250,2500, or 5000 mg/kg for 5 days/week for 13 weeks. All animals in the 5000 mg/kgdose group died within the first week. At the 2500 mg/kg dose level, one femaleand 8 males died; however, two of these deaths were attributed to gavage errors.No significant changes in hematology or urinalysis were observed in the treatedanimals at any dose level. In females, liver, kidney and brain weights were all sig-nificantly increased at doses of 1250 mg/kg or greater. In males, liver and kidneyweights were significantly increased at the 625 mg/kg dose level and above.Lesions in the liver and nephrosis were observed in animals at 2500 and 5000mg/kg. Histopathological changes were also observed in the brain and urinary

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bladder at 1250, 2500, and 5000 mg/kg dose levels. The NOAEL for this study is312 mg/kg based on liver and kidney weight changes in the male rats at 625mg/kg.

The RfD of 0.2 mg/kg/day was calculated using the NOAEL of 312 mg/kg,which was converted to 223 mg/kg/day based on the gavage schedule of 5days/week. An uncertainty factor of 1000 (10 for animal to human; 10 for mostsensitive; and 10 for subchronic) was applied to the NOAEL (223 mg/kg/day) toobtain 0.2 mg/kg/day.

CYCLOHEXANE (C6)

Under TSCA Section 4, the EPA and cyclohexane producers entered into anEnforceable Consent Agreement in November 1994 to conduct the following studies:

2-generation reproduction study (in progress, report to CMA 2/97); 90-dayinhalation study in mice (report to CMA 6/96); 90-day neurotoxicity study in rats(report to CMA 6/96); 90-day inhalation study in rats (in progress, report to CMA1/97); and a developmental study in rats (pilot completed, study start 3/96).

In the inhalation developmental pilot study conducted under TSCA Section 4,rats were exposed to 0, 3000, 6000 or 9000 ppm cyclohexane. At 6000 and 9000ppm, maternal weight gain and overall food consumption was reduced. There wasan increased incidence of “stain chin” and “stain face,” and generally diminishedresponse of the animals to a sound stimulus while being exposed. No statisticallysignificant differences were noted between control and treated groups in fertility,number of implants, number of resorptions, number of live fetuses, sex ratio, ormean fetal weight. There were no external fetal alterations noted.

Bevan, C. J. (Draft Document). 1995. Cyclohexane Testing Program Update.

Rabbits exposed to 786 ppm cyclohexane, 6 hours/day, 5 days/week for 10 weeksshowed microscopic changes in the liver and kidney. No effects occurred in rabbitsexposed to 434 ppm for either 10 or 26 weeks. No treatment related effectsoccurred in monkeys exposed at 1243 ppm cyclohexane for 10 weeks.

Treon, J.F., Crutchfield, W.E., Jr., and Kitzmiller, K.V. 1943. The physiological response of animals to cyclo-hexane, methylcyclohexane, and certain derivatives of these compounds. J. Ind. Hyg. Toxicol. 25:323-347.

In a study to assess the neurotoxic potential of cyclohexane, rats were exposed to avapor of 1500 or 2500 ppm, 3 to 10 hours/day, 5 to 6 days/week, for periods up to30 weeks. No histopathologic effects were detected in the peripheral nervoussystem; however, the central nervous system was not evaluated.

Frontali, N., Amantini, M.C., Spagnoto, A., Guarcini, A.M., Saltari, M.C., Burgnone, F., and Perbillini, L.Experimental neurotoxicity and urinary metabolites of C5-C7 aliphatic hydrocarbons used as glue sol-vents in shoe manufacture. Clinical Toxicology, 18(12):1357-1367, 1981.

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1-HEXENE (C6)

In a reproduction/developmental screening study (OECD guideline 421), rats(12/sex/group) were administered 1-hexene in corn oil, by oral gavage, at levelsof 0, 100, 500 or 1000 mg/kg/day at a volume of 5 mL/kg. The F0 males weretreated for 28 days prior to mating and until sacrifice (44 days of dosing). The F0females were treated 14 days prior to mating, during mating, throughout gestationand lactation, and until sacrifice (41-55 total days of dosing). F1 pups were sacri-ficed on day 4 of lactation. No mortality or clinical signs of toxicity were observedduring the study. Body weight, body weight gain, food consumption and organweights were unremarkable. Histopathologic evaluations of ovaries, testes, epi-didymides, liver, and peripheral nerve were unremarkable. Kidney effects, indica-tive of hydrocarbon nephropathy, were evident in males at all dose levels. No evi-dence of impaired reproductive capabilities was observed in the F0 parents, and noevidence of developmental toxicity was observed in the F1 pups. A NOAEL forreproductive toxicity was considered to be 1000 mg/kg/day.

Springborn Laboratories (SLS). March 24, 1995. Reproduction/Developmental Toxicity Screening Test inRats with 1-Hexene. Submitted to Chemical Manufacturers Association. SLS Study No. 3325.1.

Rats (40/sex/group) were exposed to a vapor concentration of 1-hexene at 0,300, 1000, or 3000 ppm, 6 hours/day, 5 days/week, for 90-days. No mortalitiesoccurred. Female rats exposed at 3000 ppm had significantly reduced bodyweights. Male rats exposed to 3000 had slightly lower body weights compared tocontrols. Exposure to 1-hexene had no effect on neuromuscular coordination infemales or on sperm count in males. At termination, serum phosphorous levelswere significantly elevated in males at 300 ppm, and in male and female rats at 1000and 3000 ppm. In addition, hematocrit and RBC levels were elevated for males andfemales at 3000 ppm and in females at 1000 ppm. Mean corpuscular hemoglobinand mean corpuscular hemoglobin concentrations were depressed in femalesexposed at 1000 and 3000 ppm. Both absolute and relative testes weights increasedin males at 3000 ppm. However, no gross or histopathologic lesions were observedin any tissue at interim or terminal sacrifice. The NOAEL was determined at 1000ppm. However, based on the effects observed at 1000 ppm, a NOAEL of 300 ppmmay be more appropriate.

APME Monomer Dossier Re: SCF PMN/Reference No. 18820 (1-Hexene), 1995.

Rats (10/sex/group) were administered undiluted 1-hexene by oral gavage, dailyfor 13 weeks at 101, 350, 700 and 1010 mg/kg body weight/day. Some animals died(3 at 350 mg/kg; 7 at 700 mg/kg and 5 at 1010 mg/kg) due to hydrocarboninduced chemical pneumonitis. Food consumption was reduced in rats exposed at700 and 1010 mg/kg 1-hexene, and body weight gain was reduced in males.Hematology, clinical chemistry and urinalysis were generally unremarkable exceptfor some minor changes seen in these values in males exposed at 700 and/or 1010mg/kg. Neurotoxicity evaluations showed some non-dose related differencesbetween control and treated animals. Histologic evaluations were performed onlywith animals that died during the study, to avoid a statistical distortion resultingfrom the aspiration-related deaths. Most treated animals showed effects indicative

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of forestomach irritation from undiluted 1-hexene. The NOAEL for this study wasdetermined to be 350 mg/kg body weight/day.

APME Monomer Dossier Re: SCF PMN/Reference No. 18820 (1-Hexene), 1995.

METHYLCYCLOHEXANE (C7)

Rats, mice, hamsters and dogs were exposed to a vapor of methylcyclohexane at 0,400 or 2000 ppm, 6 hours/day, 5 days per week for 12 months. At 12 months, someof the rats, mice, and hamsters were terminated. The remaining rodents were heldan additional year and the dogs for five years. There was no increase in tumors inany of the exposed animals. The only treatment related finding was kidneynephropathy in the 2000 ppm exposed rats. Hemolysis of blood samples prohibit-ed clinical chemistry evaluations for the female rats.

Kinkead, E.R., Haun, C.C., Schneider, M.G., Vernot, E.H., and Macewen, J.D. (1985) Chronic inhalationexposure of experimental animals to methylcyclohexane. Air Force Aerospace Medical Research ReportAFAMRL-TR-85-03.

Rabbits were exposed to a vapor of methylcyclohexane for 10 weeks. Liver andkidney effects were reported in rabbits exposed to 2880 ppm; however, there wereno effects at 1200 ppm. No treatment related effects were reported in a monkeyexposed to 370 ppm methylcyclohexane for 10 weeks.

Treon, J.F., Crutchfield, W.E., Jr., and Kitzmiller, K.V. (1943). The physiological response of animals tocyclohexane, methylcyclohexane, and certain derivatives of these compounds. J. Ind. Hyg. Toxicol.25:323-347.

ETHYLBENZENE (C8)

The chosen study is a rat 182-day oral bioassay in which ethylbenzene was given 5days/week at doses of 13.6, 136, 408, or 680 mg/kg/day in olive oil gavage (Wolfet al., 1956). There were 10 albino female rats/dose group and 20 controls. Thecriteria considered in judging the toxic effects on the test animals were growth,mortality, appearance and behavior, hematologic findings, terminal concentrationof urea nitrogen in the blood, final average organ and body weights, histopatho-logic findings, and bone marrow counts. The LOAEL of 408 mg/kg/day is associ-ated with histopathologic changes in liver and kidney.

The RfD of 0.1 mg/kg/day was calculated using the NOAEL of 136 mg/kg,which was converted to 97.1 mg/kg/day based on the gavage schedule of 5days/week. An uncertainty factor of 1000 (10 for animal to human; 10 for mostsensitive; and 10 for subchronic) was applied to the NOAEL (97.1 mg/kg/day) toobtain 0.1 mg/kg/day.

STYRENE (C8)

Four beagle dogs/sex were gavaged with doses of 0, 200, 400, or 600 mg styrene/kgbw/day in peanut oil for 560 days (Quast et al., 1979). No adverse effects wereobserved for dogs administered styrene at 200 mg/kg-day. In the higher dosegroups, increased numbers of Heinz bodies in the RBCs, decreased packed cellvolume, and sporadic decreases in hemoglobin and RBC counts were observed. In

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addition, increased iron deposits and elevated numbers of Heinz bodies werefound in the livers. Marked individual variations in blood cell parameters werenoted for animals at the same dose level. Other parameters examined were bodyweight, organ weights, urinalyses, and clinical chemistry. The NOAEL in this studyis 200 mg/kg-day and the LOAEL is 400 mg/kg-day.

The RfD of 0.2 mg/kg/day was calculated using the NOAEL of 200 mg/kg/day.An uncertainty factor of 1000 (10 for animal to human; 10 for most sensitive; and10 for subchronic) was applied to the NOAEL (200 mg/kg/day) to obtain 0.2mg/kg/day.

XYLENES (C8)

Groups of 50 male and 50 female Fischer 344 rats and 50 male and 50 femaleB6C3F1 mice were given gavage doses of 0, 250, or 500 mg/kg/day (rats) and 0,500, or 1000 mg/kg/day (mice) for 5 days/week for 103 weeks (NTP, 1986). Theanimals were observed for clinical signs of toxicity, body weight gain, and mortali-ty. All animals that died or were killed at sacrifice were given gross necropsy andcomprehensive histologic examinations. There was a dose-related increased mor-tality in male rats, and the increase was significantly greater in the high-dose groupcompared with controls. Although increased mortality was observed at 250mg/kg/day, the increase was not significant. Although many of the early deathswere caused by gavage error, NTP (1986) did not rule out the possibility that therats were resisting gavage dosing because of the behavioral effects of xylene. Micegiven the high dose exhibited hyperactivity, a manifestation of CNS toxicity. Therewere no compound related histopathologic lesions in any of the treated rats ormice. Therefore, the high dose is a FEL and the low dose a NOAEL.

The RfD of 2 mg/kg/day was calculated using the NOAEL of 250 mg/kg, whichwas converted to 179 mg/kg/day based on the gavage schedule of 5 days/week. Anuncertainty factor of 100 (10 for animal to human and 10 for most sensitive) wasapplied to the NOAEL (179 mg/kg/day) to obtain 2 mg/kg/day.

ISOPROPYLBENZENE (CUMENE) (C9)

Rats were exposed to cumene vapor at concentrations of 0, 100, 500 and 1200 ppm(0, 0.50, 2.48 and 6.01 mg/L), 6 hours/day, 5 days/week for 13 weeks. A satellitegroup received a single 6-hour exposure, in order to evaluate neurobehavior.Alterations in functional observational battery (FOB) were observed in the satellitegroup at 500 and 1200 ppm, at 1 and 6 hours post exposure, but not at 24 hourspost exposure. Effects included abnormal gaits, increased activity, decreased rectaltemperature, and decreased toe pinch withdrawal reflexes. Necropsies were notperformed in the single exposure study.

In the 13 week inhalation study, no exposure related deaths occurred. No dif-ferences were observed in mean body weight; however, decreased food consump-tion was noted Week 1 for females exposed at 500 and 1200 ppm. A consistentincrease in water consumption was noted in males exposed at 500 and 1200 ppmfrom Week 2 onward. These groups also demonstrated changes in several hema-tologic and clinical chemistry parameters. No exposure-related changes were seenin brain measurements, functional observational battery, or nervous system

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histopathology. Motor activity decreased in males exposed to 500 and 1200 ppm.This effect was not observed in a subsequent 13 week inhalation study, reported bythe same author. There were no exposure-related effects on spermatogenesis.Liver, kidney and adrenal gland weights were increased in the 500 and 1200 ppmgroups. Renal proximal tubular cell hypertrophy, hyperplasia, and hyaline dropletformation was evident in males exposed to 500 and 1200 ppm cumene. Cataractswere observed, however, in a non-dose dependent manner and in both exposedand control animals. Cumene was not considered neurotoxic. The NOAEL forthis study was determined at 100 ppm.

Cushman, J.R., Norris, J.C., Dodd, D.E., Darmer, K.I., and Morris, C.R. 1995. Subchronic inhalation toxi-city and neurotoxicity assessment of cumene in Fischer 344 rats. J. Am. Coll. Tox. 14(2): 129-147.

In a second 13 week inhalation study, conducted to assess the high incidence ofcataracts observed in the first study, rats were exposed to cumene vapor, 6hours/day, 5 days/week at concentrations of 0, 50 (permissible exposure limit),100, 500 and 1200 ppm (0, 0.25, 0.50, 2.50 and 6.00 mg/L), with a 4 week recoveryperiod. No animals died during the study. Body weights were unremarkable.Although some relative and absolute liver, kidney and adrenal gland weights wereincreased in rats exposed at 500 or 1200 ppm, no histopathological evaluationswere conducted. The eyes were the only tissue evaluated histopathologically. Notreatment related ophthalmic effects were observed. No serum chemistry orhematological evaluations were conducted. No changes in functional observation-al battery, auditory brain stem response, or motor activity were observed in anydose group. No treatment related neurotoxic or ototoxic effects were noted. TheNOAEL for this study is 100 ppm, and is in agreement with the initial 13 week studyconducted by Cushman et al. (1995).

Cushman, J.R., Norris, J.C., Dodd., D.E., Darmer, K.I., and Morris, C.R. 1995. Subchronic inhalation tox-icity and neurotoxicity assessment of cumene in Fischer 344 rats. J. Am. Coll. Tox. 14(2): 129-147.

Rats were exposed to cumene vapor at concentrations of 0, 105, 300, or 599 ppm(0, 0.53, 1.5 and 3.0 mg/L), 6 hours/day, 5 days/week for approximately 28 days.No animals died during the study. Hypoactivity and irritation effects were notedduring exposure. Absolute and relative liver and/or kidney weights wereincreased. No changes were reported in mean body weight, clinical, gross ormicroscopic pathology findings. The NOAEL was > 3 mg/L.

EUCLID Data Sheet: Cumene. 1995. Section 5.4 Repeated Dose Toxicity. ICI Chemicals & Polymers. EBSIDocument No. 96MRR 54.

Female rats were exposed to 0, 100, 500 or 1200 ppm cumene vapor, 6 hours/day,on days 6 - 15 of gestation. No dams died, aborted or delivered early. However,body weight gain was significantly reduced throughout the exposure period indams in the 1200 ppm group, and maternal food consumption was reduced at 1200and 500 ppm. Gross observations, body weight, and organ weights were unre-markable except for a significant increase in relative liver weight at 1200 ppm. Nosignificant changes were noted in gestational parameters and no increased inci-dence of either malformations or variations were noted. The NOEL for develop-mental toxicity was greater than 1200 ppm.

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EUCLID Data Sheet: Cumene. 1995. Section 5.9 Developmental Toxicity/Teratogenicity. ICI Chemicals& Polymers. EBSI Document No. 96MRR 54.

Female rabbits were exposed to 0, 500, 1200 or 2300 ppm cumene vapor, 6 hours/day,on days 6 - 18 of gestation. Maternal toxicity occurred in all three treatment groupsas evidenced by maternal deaths, reduced relative liver weight (2300 ppm), andreduced maternal weight gain and food consumption during the exposure period.There were no significant changes in gestational parameters and no increased inci-dence of malformations or variations. However, one significant variation, ecchymosisof the head, was observed at 500 ppm but was within range of historical control values.The NOEL for developmental toxicity was greater than 2300 ppm.

EUCLID Data Sheet: Cumene. 1995. Section 5.9 Developmental Toxicity/Teratogenicity. ICI Chemicals& Polymers. EBSI Document No. 96MRR 54.

Groups of 10 female Wistar rats were administered 139 doses of cumene by gavagein olive oil at 154, 462, or 769 mg/kg/day over a 194-day period; 20 rats given oliveoil served as controls (Wolf et al., 1956). Body weights were measured throughoutthe study. Most hematological evaluations were conducted after the 20, 40, 80, and130th doses, and blood urea nitrogen determinations, and gross and histologicalexaminations (lungs, heart, liver, kidneys, testes, spleen, adrenals, pancreas,femoral bone marrow) were conducted at the end of the study. Effects were notobserved at 154 mg/kg/day but a “slight” but significant increase in average kidneyweight occurred at 462 mg/kg/day. A “moderate” increase in average kidneyweight occurred at 769 mg/kg/day. Therefore, 154 mg/kg/day is the NOAEL and462 mg/kg/day is the LOAEL based on increased kidney weight.

The RfD of 0.04 mg/kg/day was calculated using the NOAEL of 154 mg/kg,which was converted to a 110 mg/kg/day based dosing schedule of 139 doses in194 days. An uncertainty factor of 3000 (10 for animal to human; 10 for most sen-sitive; 10 for subchronic; and an additional 3 for inadequate database) was appliedto the NOAEL (110 mg/kg/day) to obtain 0.04 mg/kg/day.

N-NONANE(C9)

Harlan-Wistar rats were exposed by inhalation to 0, 1900, 3100 or 8400 mg/m3 (0,360, 590, or 1600 ppm) n-nonane 6 hours/day, 5 days/week for 13 weeks. Twodeaths resulted at 1600 ppm. Exposure to 1600 ppm produced excessive salivation,mild coordination loss, and fine tremors throughout the first 4 days of exposure.Salivation and lacrimation continued throughout the study. Mean body weights ormean body weight changes were significantly lower in the 1600 ppm group. Therewere no hematological, serum chemistry or histopathologic changes that were con-sidered treatment-related. No effects were observed at 360 or 590 ppm.

Carpenter et al. 1975. Petroleum hydrocarbon toxicity studies XVII. Animal response to n-nonane vapor.Toxicol. Appl. Pharmacol. 44: 53-61.

N-PROPYLBENZENE (C9)

Rabbits (15/group) were fed n-propylbenzene in the diet at 0, 2.5 and 25 mg/kg/dayfor a 6 month period. Appearance, body weight, organ weights and protein function

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of the liver were unremarkable. Some animals showed mild protein dystrophy of theliver and kidneys. At 25 mg/kg, a non-significant decrease in RBC count was notedwith deposition of hemosiderin in the spleen, indicating red-cell destruction.Leukocyte counts increased (nonsignificant) in both dose groups.

National Research Council. 1977. Drinking Water and Health. p. 763.

1,3,5-TRIMETHYLBENZENE (C9)

Sprague Dawley rats (10/sex/dose group) were administered 1,3,5-trimethyl-benzene in corn oil by oral gavage for a 14 day period at concentrations of 0, 60,150 and 600 mg/kg/day at a constant volume of 5mL/kg/day. A high dose recov-ery group was retained an additional 14 days. All animals survived treatment. Noadverse clinical signs or treatment-related effects were observed in body weight,body weight gain or food consumption. Ophthalmic and necropsy findings wereunremarkable. An increase in cholesterol levels was noted in mid- and high-dosefemales. An increase in white blood cell counts with corresponding increases inneutrophils and lymphocytes was noted in high dose males. At treatment termi-nation, relative liver weights were significantly increased for mid- and high dosefemales and high dose males. In addition, relative adrenal weight was significantlyincreased in high dose males. All high dose animals exhibited centrilobularhepatic hypertrophy following treatment. All noted effects reversed by the end ofthe 14-day recovery period. The NOEL for this study was determined at 60 mg/kg,based on increased cholesterol levels and liver weight at 150 and 600 mg/kg.

IIT Research Institute. 14-Day Oral Gavage Toxicity Study of 1,3,5-Trimethylbenzene in Rats with aRecovery Group. IITRI Project No. L08512. Study 1. February 1995.

Sprague Dawley rats (10/sex/dose group) were administered 1,3,5-trimethylben-zene in corn oil by oral gavage, 5 days per week for a 90 day period at concentra-tions of 0, 50, 200 and 600 mg/kg/day at a constant volume of 5mL/kg/day. Ahigh dose recovery group was retained an additional 28 days without treatment. Alltissues from the control and high dose groups underwent microscopic examina-tion. Lesions and limited tissues were evaluated in the low and mid-dose groups.No histologic evaluations were conducted for the recovery group. All animals sur-vived treatment. No statistically significant effects were reported for body weight,body weight gain or food consumption. However, cumulative body weight gaindecreased by 11% in high dose males. Ophthalmic exams were unremarkable.Phosphorus levels increased for high dose females. Also, a significant increase inabsolute and relative liver weight was reported for high dose females at treatmenttermination. In males, relative liver and kidney weights were significantly increasedat treatment termination. No treatment-related microscopic lesions were observedin any animal. Any treatment-related effect was absent by the end of the 28-dayrecovery period. A NOEL was established at 200 mg/kg based on increased phos-phorous levels, liver and kidney weight reported at 600 mg/kg/day.

IIT Research Institute. 90-Day Oral Gavage Toxicity Study of 1,3,5-Trimethylbenzene in Rats with aRecovery Group. IITRI Project No. L0851. Study 2. May 1995.

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T-BUTYLBENZENE (C10)

t-Butylbenzene did not induce morphological transformation of Syrian hamsterembryo cells.

Rivedal, E., Mikalsen, S.-O., Roseng, L.E., Sanner, T., and Eide, I. 1992, Effects of hydrocarbons on trans-formation and intercellular communication in Syrian hamster embryo cells. Pharm. Tox. 71: 57-61.

t-Butylbenzene was negative in bacterial mutation assays, a mitotic gene conversionassay, and in a cultured rat-liver cell line for structural chromosome damage.

Dean, B.J., Brooks, T.M., Hodson-Walker, G., and Hutson, D.H. 1985. Genetic toxicology testing of 41industrial chemicals. Mutat. Res. 153:57-77.

N-DECANE (C10)

Rats were exposed to 540 ppm n-decane vapor 18 hours/day, 7 days/week for atotal of 123 days. There was a significant weight gain and increase in total leuko-cyte count compared to controls. No changes were noted in polymorphonuclear-lymphocyte ratios, in bone marrow composition, and no significant gross or micro-scopic organ changes were noted. No information was given as to whether thehematological changes were within normal biological variation. Some rats held forone month without additional exposure did not differ from the controls.

Nau, C.A., Neal, J., and Thornton, M. 1966. C9-C12 fractions obtained from petroleum distillates. ArchEnviron. Health 12: 382-393.

DIETHYLBENZENE (C10)

Rats (25 females/group) were administered 0, 20, 100 or 200 mg/kg/day diethyl-benzene in corn oil at 5 mL/kg, on days 6 through 15 of gestation. No treatment-related mortalities or clinical signs of toxicity were observed. Mean maternal bodyweight gain and food consumption were reduced at 100 and 200 mg/kg. Meanfetal body weight gain was reduced at 200 mg/kg, a level which was maternallytoxic. A greenish-blue discoloration of the amniotic sac was evident at 100 and 200mg/kg, and increased in intensity in a dose-dependent manner. No treatment-related malformations or developmental variations were observed. The NOEL formaternal toxicity was considered 20 mg/kg/day and the NOEL for fetal toxicitywas considered 100 mg/kg/day.

Submission from Monsanto Chemical Company to U.S. EPA. TSCA 8(e) Reporting. May 27, 1992. EPADocument No. 88-920003153.

NAPHTHALENE (C10)

Rabbits exposed to naphthalene by oral route at doses up to 400 mg/kg/day ongestation days 6 to 18 showed no apparent adverse reproductive effects (or signs ofdevelopmental toxicity).

Pharmakon Research International (PRI), Inc. 1986. Developmental toxicity study in rabbits:Naphthalene. Report to Texaco, Inc. Beacon, NY. PH 329-TX-001-85.

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Mice exposed to naphthalene (in corn oil) at a dose of 300 mg/kg/day on days 7to 14 of gestation had a decreased number of live pups per litter. No congenitalabnormalities were observed.

Plasterer, M.R., Bradshaw, W.S., Booth, G.M., et al. 1985. Developmental toxicity of nine selected com-pounds following prenatal exposure in the mouse: naphthalene, p-nitrophenol, sodium selenite, dimethylphthalate, ethylene thiourea and four glycol ether derivatives. Toxicol. Environ. Health 15:25-38.

In a 90 day oral gavage study, mice were administered 5.3, 53 or 133 mg/kg naph-thalene. No treatment-related mortalities or body weight changes were reported ineither sex, and no organ weight changes were observed in males. A significantdecrease in absolute brain, liver and spleen weight was noted for females at thehighest dose; however, organ to body weight ratios were significantly different onlyfor the spleen. Although spleen weight decreased, there was no evidence ofimmunotoxicity in any treatment group for either sex. No histopathologic evalua-tions were performed in this study. Exposed mice showed no alterations in hema-tology. Several serum chemistry parameters including BUN levels in females (alldoses) and total serum protein in both sexes (53 and 133 mg/kg), showed signifi-cant dose-related changes. A corresponding increase in albumin levels was notedin males, and an increase in globulin levels was noted in both males and females.Electrolyte values were generally unaffected by treatment, except for decreasedcalcium levels in males administered 53 or 133 mg/kg naphthalene. Althoughthere were some changes, serum chemistry parameters gave little evidence of sig-nificant toxicity at any dose level.

Shopp, G.M., White, K.L., Jr., Holsapple, M.P., et al., 1984. Naphthalene toxicity in CD-1 mice: Generaltoxicology and immunotoxicology. Fund. App. Toxicol. 4:406-419.

Naphthalene was not teratogenic to pregnant rats administered up to 450mg/kg/day, by gavage, on gestation days 6 to 15. However, there was a trendtoward a dose-related increase in malformations.

National Toxicology Program (NTP). 1991a. Developmental toxicity of naphthalene (CAS No. 91-20-3) admin-istered by gavage to Sprague-Dawley (CD) rats on gestational days 6 through 15. Research Triangle Park,NC: National Toxicology Program, National Institute of Environmental Health Sciences, U.S. Department ofHealth and Human Services, Public Health Service, National Institutes of Health. TER-91006.

In a 13 week subchronic oral study, rats and mice exposed to naphthalene at dosesup to 400 and 200 mg/kg/day, respectively, showed no evidence of cardiovascular,gastrointestinal, respiratory, neurologic, renal or hepatic effects. No histopatho-logical lesions of the testes were noted in mice or rats at any dose level.

Battelle’s Columbus Laboratories (Battelle). 1980a. Subchronic toxicity study: Naphthalene (C52904)B6C3F1 mice. Report to U.S. Department of Health and Human Services, National Toxicology Program,Research Triangle Park, NC.

Battelle’s Columbus Laboratories (Battelle). 1980b. Subchronic toxicity study: Naphthalene (C52904),Fischer 344 rats. Report to U.S. Department of Health and Human Services, National ToxicologyProgram, Research Triangle Park, NC.

B6C3F1 mice were exposed to naphthalene vapors at 10 or 30 ppm, 6 hours/day, 5days/week for a 2 year period. Both sexes displayed chronic inflammation andmetaplasia of the olfactory epithelium, hyperplasia of the respiratory epithelium,and a dose-related increase in inflammatory lesions of the lungs. No treatment-

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related effects were observed for gastrointestinal, hematological, renal, hepatic,immunological or neurological systems. Female (but not male) mice exposed to30 ppm naphthalene for a lifetime exhibited a significant increase in pulmonaryalveolar/bronchiolar adenomas. NTP concluded no incidence of carcinogenicityin males and limited evidence in female mice based on increased incidence of pul-monary alveolar/bronchiolar adenomas.

National Toxicology Program (NTP). 1992a. Technical report series No. 410. Toxicology and carcinogen-esis studies of naphthalene (CAS No. 91-20-3) in B6C3F1 mice (inhalation studies). Research TrianglePark, NC: U.S. Department of Health and Human Services, Public Health Service, National Institutesof Health. NIH Publication No. 92-3141.

In a 13 week subchronic dermal study, rats treated with up to 1000 mg/kg/day naph-thalene, 6 hours/day, 5 days/week, showed an increased incidence of excoriated skinlesions and papules. Similar lesions were seen in the control and low dose groups. Atthe high dose, naphthalene exacerbated the severity of the lesions. No reported res-piratory, cardiovascular, gastrointestinal, hematological, hepatic or renal effects.

Frantz, S.W., VanMiller, J.P., and Jengler, W.C. 1986. Ninety-day (subchronic) study with naphthalene inalbino rats. Report to Texaco, Inc., Beacon, NY, by Bush Run Research Center Union Carbide, Export,PA. Project No. 49-539 revised (unpublished).

A provisional RfD for naphthalene of 0.04 mg/kg/day was developed by theUSEPA. This RfD was based on an oral subchronic NTP unpublished study (NTP,1980). In this study, rats were administered naphthalene by gavage 5 days/week for13 weeks. The dose levels used in this study were not published in any of the avail-able summaries. However, the NOEL was identified to be 50 mg/kg/day. The crit-ical effect was decreased body weight. Using the gavage schedule of 5 days/week,the 50 mg/kg/day is converted to 35.7 mg/kg/day. An uncertainty factor of 1000(10 for animal to human; 10 for most sensitive; and 10 for subchronic) is used tocalculate the RfD of 0.04 mg/kg/day.

This provisional RfD is not on IRIS nor is it in HEAST. This value was on IRISbut was pulled pending further review. The value was also removed from HEASTdue to the uncertainty in the calculation of the RfD.

TETRALIN (C10)

Cataracts resulted in guinea pigs (2/2) after 6 days of inhalation exposure, 30minutes/day at a concentration of 71 mg/kg/day tetralin. No details were providedregarding dose, animal weight or test material purity. Saturated vapor (658 ppm) wasassumed. There data are of questionable reliability due to limitations in study design.

Badinand, A., Paufique. L., and Rodier, J. 1947. Experimental intoxication with Tetraline. Arch. Mal. Prof.Med. Trav. Secur. Soc., 8:124.

Cataracts were produced by Day 11 in rabbits exposed by oral route to 118 to 235mg/kg/day tetralin. However, this study lacked controls, used immature animalsand provided no details on test material purity. Therefore, these data are of ques-tionable reliability due to limitations in study design.

G. Basile, 1939. Experiments on the action of some hydrogenation products of naphthalene (Tetralin andDecalin) on the lens and its posterior capsule of the rabbit. Boll. Ocul. 18:951-957.

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METHYLNAPHTHALENE (C11)

Exposure to methylnaphthalene in the diet of mice at concentrations of 0, 0.075 or0.15% for 81 weeks resulted in a high incidence of pulmonary alveolar proteinosis,increased sera lipid and phospholipid levels, and peripheral blood monocytes forboth sexes. The incidence of bronchiolar/alveolar adenomas was significantlyincreased in males in both treatment groups but not in females. The increase wasnot dose-dependant, and was not accompanied by an increase in incidence of bron-chiolar/alveolar carcinomas. The LOAEL for this study was 0.075%.

Murata, Y., Denda, A., Maruyama, H., and Konishi, Y. (1993) Chronic toxicity and carcinogenicity studiesof 1-methylnaphthalene in B6C3F1 mice. Fund. Appl. Tox. 21: 44-51.

Four groups of CD-1 mice (20/sex/group) were gavaged daily with 0, 175, 350, or700 mg/kg/day acenaphthene for 90 days (USEPA, 1989a). The toxicological eval-uations of this study included body weight changes, food consumption, mortality,clinical pathological evaluations (including hematology and clinical chemistry),organ weights and histopathological evaluations of target organs. The results ofthis study indicated no treatment-related effects on survival, clinical signs, bodyweight changes, total food intake, and ophthalmological alterations. Liver weightchanges accompanied by microscopic alterations (cellular hypertrophy) werenoted in both mid- and high-dose animals and seemed to be dose-dependent.Additionally, high-dose males and mid- and high-dose females showed significantincreases in cholesterol levels. Although increased liver weights, without accom-panying microscopic alterations or increased cholesterol levels, were also observedat the low dose, this change was considered to be adaptive and was not consideredadverse. The LOAEL is 350 mg/kg/day based on hepatotoxicity; the NOAEL is175 mg/kg/day.

The RfD of 0.06 mg/kg/day was calculated using the NOAEL of 175 mg/kg/day.An uncertainty factor of 3000 (10 for animal to human; 10 for most sensitive; 10for subchronic; and an additional 3 for inadequate database) was applied to theNOAEL (175 mg/kg/day) to obtain 0.06 mg/kg/day.

BIPHENYL (C12)

Fifteen weanling albino rats of each sex were placed in each of eight experimentalgroups: 0.0, 0.001, 0.005, 0.01, 0.05, 0.10, 0.50, and 1.0% biphenyl in the diet(Ambrose et al., 1960). Dietary levels of 0.5% biphenyl and greater were associat-ed with kidney damage, reduced hemoglobin levels, decreased food intake, anddecreased longevity. One animal in each of the lower dose groups and controlgroup had detectable blood in the renal pelvis. A NOAEL of 0.1% of diet is chosenbecause of the uncertainty of the significance of the effects observed at lower dosesas compared to the more certain AEL of 0.5% of diet.

The RfD of 0.05 mg/kg/day was calculated using the NOAEL of 0.1%, which wasconverted to 50 mg/kg/day. An uncertainty factor of 100 (10 for animal to humanand 10 for most sensitive) and a modifying factor of 10 were applied to the NOAEL(50 mg/kg/day) to obtain 0.05 mg/kg/day.

Ambrose, A.M., Booth, A.N., DeEds, F., and A.J. Cox, Jr. 1960. A toxicological study of biphenyl, a citrusfungistat. Food. Res. 25: 328-336.

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Pregnant rats were administered biphenyl by oral gavage on days 6 to 15 of gesta-tion, at doses of 125, 250, 500 or 1000 mg/kg. No fetal or maternal toxicity result-ed from exposure at doses < 500 mg/kg. Evidence (nonsignificant) of fetotoxicitywas noted at 1000 mg/kg and consisted of reduced number of live fetuses, reducedfetal weight, and increased resorptions. However, this dose was maternally toxicand produced mortality in five dams. Neither teratogenicity nor maternal toxicitywas evident at doses ranging from 125 to 500 mg/kg biphenyl.

Khera, K.S., Whalen, C., Angers, G., and Trivett, G., 1979. Assessment of teratogenic potential of piper-onyl butoxide, biphenyl and phosalone in the rat. Toxicol. Appl. Pharmacol. 47(2): 353-358.

FLUORENE (C13)

Fluorene (C13) has an RfD of 0.04 mg/kg/day that is on IRIS. This value is based onan oral 13-week study in mice. Mice (25/sex/group) were exposed to 0, 125, 250, or500 mg/kg/day of fluorene suspended in corn oil by gavage for 13 weeks (USEPA,1989b). A significant decrease in the red blood cell count and packed cell volumewere observed in females in the 250 mg/kg/day group and in males and females atthe 500 mg/kg/day dose level. In both high dose males and females, there was a sig-nificant decrease in BUN and a significant increase in total serum bilirubin. At 250and 500 mg/kg/day, there was a significant increase in liver weight. A significantincrease in spleen and kidney weight was observed in males and females at 500mg/kg/day and males at 250 mg/kg/day. Increases in liver and spleen weights inhigh dose animals were accompanied by histopathological increases in the amountsof hemosiderin in the spleen and Kupffer cells of the liver. The LOAEL is 250mg/kg/day based on hematological effects and the NOAEL is 125 mg/kg/day.

The RfD for fluorene was calculated by taking the NOAEL of 125 mg/kg/dayand applying an uncertainty factor of 1000 (10 for animal to human; 10 for mostsensitive; and 10 for subchronic) and a modifying factor of 3 for lack of adequatetoxicity data in a second species and reproductive/developmental data.

US EPA. 1989. Mouse oral subchronic toxicity study. Prepared by Toxicity Research Laboratories, LTD.,Muskegon, MI for the Office of Solid Waste, Washington, DC.

ANTHRACENE (C14)

Anthracene was administered to groups of 20 male and female CD-1 (ICR)BR miceby oral gavage at doses of 0, 250, 500, and 1000 mg/kg/day for at least 90 days(USEPA, 1989c). Mortality, clinical signs, body weights, food consumption, opthal-mology findings, hematology and clinical chemistry results, organ weights, organ-to-body weight ratios, gross pathology, and histopathology findings were evaluated.No treatment-related effects were noted. The no observed-effect level (NOEL) isthe highest dose tested (1000 mg/kg/day).


US EPA. 1989. Subchronic Toxicity in Mice with Anthracene. Final Report. Hazelton LaboratoriesAmerica, Inc. Prepared for the Office of Solid Waste, Washington, DC.

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FLUORANTHENE (C16)

Male and female CD-1 mice (20/sex/group) were gavaged for 13 weeks with 0, 125,250, or 500 mg/kg/day fluoranthene (USEPA, 1988). A fifth group of mice (30/sex)was established in the study for baseline blood evaluations. Body weight, food con-sumption, and hematological and serum parameter values were recorded at regularintervals during the experiment. At the end of 13 weeks, the animals were sacrificedand autopsied, which included organ weight measurement and histological evalua-tion. All treated mice exhibited nephropathy, increased salivation, and increasedliver enzyme levels in a dose-dependent manner. However, these effects were eithernot significant, not dose-related, or not considered adverse at 125 mg/kg/day. Miceexposed to 500 mg/kg/day had increased food consumption and increased bodyweight. Mice exposed to 250 and 500 mg/kg/day had statistically increased SGPTvalues and increased absolute and relative liver weights. Compound-related micro-scopic liver lesions (indicated by pigmentation) were observed in 65 and 87.5% ofthe mid- and high-dose mice, respectively. Based on increased SGPT levels, kidneyand liver pathology, and clinical and hematological changes, the LOAEL is consid-ered to be 250 mg/kg/day, and the NOAEL is 125 mg/kg/day.


US EPA. 1988. 13-Week mouse oral subchronic toxicity study. Prepared by Toxicity ResearchLaboratories, Ltd., Muskegon, MI for the Office of Solid Waste, Washington, DC.

PYRENE (C16)

An oral RfD of 0.03 mg/kg/day for pyrene is currently on IRIS. This value wasbased on a subchronic oral gavage study in mice (USEPA, 1989d). Groups of 20mice/sex/group were administered pyrene in corn oil at levels of 0, 75, 125, or 250mg/kg for 13 weeks. Nephropathy was present in 4 (control), 1 (75 mg/kg/day),1 (125 mg/kg/day), and 9 (250 mg/kg/day) male mice. Similar lesions were seenin female mice: 2 (control), 3 (75 mg/kg/day), 7 (125 mg/kg/day), and 10 (250mg/kg/day). Decreased kidney weights were observed in the 125 and 250mg/kg/day dose groups. The NOAEL was determined to be 75 mg/kg/day andthe LOAEL was 125 mg/kg/day for nephropathy and decreased kidney weights.

The RfD for pyrene was calculated by taking the NOAEL of 75 mg/kg/day andapplying an uncertainty factor of 1000 (10 for animal to human; 10 for most sen-sitive; and 10 for subchronic) and a modifying factor of 3 for lack of adequate tox-icity data in a second species and reproductive/developmental data.

US EPA. 1989. Mouse Oral Subchronic Toxicity of Pyrene. Study conducted by Toxicity ResearchLaboratories, Muskegon, MI for the Office of Solid Waste, Washington, DC.

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BENZ(A)ANTHRACENE (C18)

Classified as a B2 carcinogen - use B(a)P slope factor and a potency factor. Mice (20 male - B6AF1/J) were administered two doses of benz(a)anthracene at a

concentration of 3% by oral gavage (Klein, 1963). Treated animals exhibited anincreased incidence of hepatomas (80%) and pulmonary adenomas (85%) over thecontrol incidence values of 10% and 30%, respectively. In the same study, 40 maleB6AF1/J mice were administered by gavage benz(a)anthracene 15 times at a con-centration of 3%. Animals exhibited elevated incidences of hepatomas (46%) andlung adenomas (95%) over control values of 0% and 30%, respectively (Klein, 1963).

Benzo(a)pyrene and benz(a)anthracene (a range of concentrations) were appliedto the backs of C3H/He mice (sex unspecified) three times a week for 50 weeks (20to 40 mice/dose) (Bingham and Falk, 1969). Benzo(a)pyrene was dissolved indecalin and benz(a)anthracene was dissolved in toluene for application. At 50weeks, animals were sacrificed and tumors were quantitated. Tumors were classifiedas either malignant or benign, but no further details were provided. No solvent con-trols were included in the study. Both compounds produced malignant and benignskin tumors. Benz(a)anthracene appeared to be less potent than benzo(a)pyrene;however, the use of different solvents could be a confounding factor.

Bingham, E. and Falk, H.L. (1969). The modifying effect of carcinogens on the threshold response. Arch.Environ. Health 19:779-783.

Klein, M. (1963). Susceptibility of strain B6AF/J hybrid infant mice to tumorigenesis with 1,2-benzan-thracene, deoxycholic acid, and 3-methylcholanthrene. Cancer Res. 23:1701-1707.

CHRYSENE (C18)

Classified as a B2 carcinogen - use B(a)P slope factor and a potency factor.

BENZO(B)FLUORANTHENE (C20)

Classified as a B2 carcinogen - use B(a)P slope factor and a potency factor. Seven PAHs (benzo(a)pyrene, benzo(b)fluoranthene, benzo(j)fluoranthene,

benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene, cyclopentadieno(cd)pyrene, andcoronene) were tested at varying concentrations to determine their dose-responserelationships as carcinogens when applied topically to the backs of female NMRImice two times a week for the lifetime of the animal (40 mice/dose) (Habs et al.,1980). At death, all animals were dissected and their dorsal skin examined histo-logically for tumor formation. A clear dose-response relationship was observed atthe site of application for benzo(a)pyrene. Benzo(b)fluoranthene showed a clearcarcinogenic effect. Benzo(j)fluoranthene exhibited weak carcinogenic effects,while benzo(k)fluoranthene and indeno(1,2,3-cd)pyrene showed no carcinogeniceffect. In this study, the results were reported as tumors and no other distinctionwas defined. However, it is assumed that the tumors were all carcinomas based onthis statement from the study, “Animals at an advanced state of macroscopicallyclearly infiltrative growth were killed.”

Benzo(a)pyrene, benzo(b)fluoranthene, benzo(j)fluoranthene, benzo(k)fluo-ranthene at concentrations between 0.01% and 0.5% dissolved in acetone wereapplied to the clipped backs of female Swiss mice (20/dose/chemical) three times

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per week for the lifetime of the animals (Wynder and Hoffmann, 1959). Resultsshow that benzo(a)pyrene, benzo(b)fluoranthene, and benzo(j)fluoranthene pro-duced high incidences of skin papillomas and carcinomas at all dose levels.Benzo(k)fluoranthene produced a limited number of papillomas only at the highdose level (0.5%). There were no control groups in the study.

Habs, M., Schmahl, D., and Misfeld, J. (1980). Local carcinogenicity of some environmentally relevantpolycyclic aromatic hydrocarbons after lifelong topical application to mouse skin. Arch.Geschwulstforsch. 50:266-274.

Wynder, E.L. and Hoffmann, D. (1959). The carcinogenicity of benzo(b)fluoranthene. Cancer. 12:1194.

BENZO(K)FLUORANTHEN (C20)


BENZO(GHI)PERYLENE (C20)

Female Ha/ICR/mil Swiss albino mice (20/dose level) received three weeklytopical applications of B(a)P, benzo(ghi)perylene, or indeno(1,2,3-cd)pyrene forone year at various concentrations (Hoffmann and Wynder, 1966). B(a)P andbenzo(ghi)perylene were dissolved in dioxane and indeno(1,2,3-cd)pyrene wasdissolved in acetone. There were dioxane controls but no acetone controls.Tumors were observed at 30 and 35% in the higher dose groups (0.1 and 0.5%,respectively) of indeno(1,2,3-cd)pyrene but not in the two lower dose groups (0.01and 0.05%). B(a)P produced tumors in 85 and 95% of the animals at concentra-tions of 0.05 and 0.1%, respectively.

Hoffmann, D. and Wynder, E.L. (1966). Beitrag zur carcinogen Wirkung von Dibenzopyrenen. Z.Krebsforsch. 68:137-149.

DIBENZ(AH)ANTHRACENE (C22)


BENZO(A)PYRENE (C20)

Classified as a B2 carcinogen- slope factor 7.3 (mg/kg/day)-1.Male and female CFW mice were administered dietary doses of B(a)P at con-

centrations up to 1000 ppm for varying lengths of time (23 to 238 days) (Rigdonand Neal 1966, 1969). Treated mice exhibited an increased incidence of forestom-ach tumors. At the 250 ppm level, 64% of the animals developed papillomas or car-cinomas of the forestomach, while 100% of the mice fed 1000 ppm exhibitedtumors of the forestomach.

Male and female CFW mice were fed B(a)P at concentrations of 0, 1, 10, 20, 30,40, 45, 50, 100, and 250 ppm in the diet (Neal and Rigdon, 1967). The food wasgiven ad libitum and the amount of food ingested per day was not measured andwas assumed to be 4 g per day. The number of mice per exposure level rangedfrom 23 to 73 and the length of exposure varied from 70 8 to 197 days. There werealso variations in the age of the animals at the beginning of the experiment (17 to101 days) and the interval between the end of exposure and death (2 to 101 days).

96

There were 289 mice in the control group. At autopsy, the stomachs were removedand washed with tap water and macroscopically examined. Select specimens werefixed for histological analysis. No forestomach tumors were reported in the 0, 1,and 10 ppm dose groups. The incidence of forestomach tumors in the 20, 30, 40,45, 50, 100, and 250 ppm dose groups were 1/23, 0/37, 1/40, 4/40, 24/34, 19/23,and 66/73, respectively. There is no indication of any other organ being evaluat-ed either macro- or microscopically.

Brune et al. (1981) exposed five groups of Sprague-Dawley rats (32/sex/group)to B(a)P at a concentration of 0.15 mg/kg. Three of the groups were exposed bygavage with different exposure regimens: 5 times/week, every 3rd day, or every 9thday. The remaining two groups were exposed through the diet either 5times/week or every 9th day. Exposures lasted for the lifetime of the animals whichvaried from 87 to 131 weeks. This study focused on the development of tumors inthe gastrointestinal tract. The combined incidence of tumors of the forestomach,esophagus, and larynx was 3/64, 3/64, and 10/64 for the control group, the groupfed B(a)P in the diet every 9th day, and the group fed B(a)P in the diet 5times/week, respectively. Tumors at other sites (i.e., mammary gland, kidney, pan-creas, lung, urinary bladder, testes) were determined to be spontaneous becausethey were observed at similar incidence levels in control animals. However, thedata on the number of tumors in treated and control animals at these other loca-tions were not reported in the study.

Thyssen et al. (1981) exposed (nose only) Syrian golden hamsters to an averageconcentration of 2.2, 9.5, and 46.5 mg/m3 of B(a)P for 4.5 hours/day, 7 days/weekfor the first 10 weeks and 3 hours/day for the remainder of the treatment time.Animals exposed to 0, 2.2, 9.5 and 46.5 mg/m3 were exposed for a total 96.4, 95.2,96.4, and 59.5 weeks, respectively. The numbers of animals per group were 27, 27,26, and 25 for controls, low-, mid-, and high-dose groups, respectively. Animalswere sacrificed and organs were fixed and sections for histology were prepared.Tumor data were presented for respiratory tract, digestive tract, and other sites. Inthe other sites category, tumors from the pituitary gland, harderian gland, thyroidgland, parathyroid gland, liver, pancreatic islets, pancreatic ducts, kidneys, adrenalgland, and colon were combined. The incidences of respiratory tract tumors were0/27 for controls, 0/27 for the low-dose group, 9/26 for the mid-dose group, and13/25 for the high-dose group. The highest exposure level did have an impact onsurvival time when compared with controls (59.5 weeks for high-dose vs. 96.4 weeksfor control).

Brune, H., Deutsch-Wenzel, R.P., Habs, M., Ivankovic, S., and Schmahl, D. (1981). Investigation of thetumorigenic response to benzo(a)pyrene in aqueous caffeine solution applied orally to Sprague-Dawleyrats. J. Cancer Res. Clin. Oncol. 102:153-157.

Neal, J. and Rigdon, R.H. (1967). Gastric tumors in mice fed benzo(a)pyrene: A quantitative study. Tex.Rep. Biol. Med. 25: 553-557.

Rigdon, R.H. and Neal, J. (1966). Gastric carcinomas and pulmonary adenomas in mice fedbenzo(a)pyrene. Tex. Rep. Biol. Med. 24:195-207.

Rigdon, R.H. and Neal, J. (1969). Relationship of leukemia to lung and stomach tumors in mice fedbenzo(a)pyrene. Proc. Soc. Exp. Biol. Med. 130:146-148.

Thyssen, J., Althoff, J.K.G., and Mohr, U. (1981). Inhalation studies with benzo(a)pyrene in Syrian goldenhamsters. J. Natl. Cancer Inst. 66:575-577.

97

APPENDIX C

Review of American Petroleum Institute’s (API’s)Toxicity Data on Selected Refinery Streams

SUMMARY

REVIEW OF AMERICAN PETROLEUM INSTITUTE’S (API’S) TOXICITY DATA ON SELECTEDREFINERY STREAMS

The objective of this section was to review the API’s toxicity data on selected refin-ery streams in order to:

1. determine whether any of the refinery streams were similar inoverall composition to the equivalent carbon ranges of the sur-rogate fractions

2. determine whether any of the toxicity studies on the refinerystreams could be used to develop oral reference doses (RfDs).

Analytical data were available for each of the streams which were tested.However, the compositional analysis varied depending on the stream. Detailed GC-MS data were available for each of the nine naphtha streams. From this data, theweight percent of the individual hydrocarbons with differing carbon numbers wasdetermined. However, for the remaining 28 streams, the only analytical data avail-able were information from the distillation curve for the material (i.e., the volumepercent distilled off at differing temperatures) and the total percent of saturates,olefins, and aromatics in the stream. Using the distillation data, the carbonnumbers of the compounds distilling off at different temperatures was estimated.It was then assumed that each boiling range had the same percentage of aliphaticsand aromatics. In this way, the percent of aliphatics and aromatics in the variousfractions was estimated. However, it must be noted that since the analytical datawere limited, the estimates of the percent aliphatics and aromatics in the carbonranges of interest remain highly uncertain.

During the next phase of the review, the toxicity data on the refinery streamswere evaluated in order to determine whether the data could be used to developoral reference doses (RfDs). The data reviewed included 26 chronic dermal car-cinogenicity studies, 5 subchronic inhalation studies, and 30 subchronic dermalstudies. There were no chronic or subchronic oral studies available for any of therefinery streams. Based on the review, it was determined that only two subchronicinhalation studies would be considered appropriate by the US EPA for the devel-opment of oral RfDs. The chronic data were deemed unacceptable for the devel-opment of RfDs because in these studies only a single dose was tested and systemiceffects were not evaluated. The subchronic dermal studies could not be usedbecause no absorption data were available. In addition, only two of the five sub-chronic inhalation studies were done using multiple doses and could be used todevelop oral RfDs. However, in order to develop oral RfDs from the subchronicinhalation studies, route-to-route extrapolation was required. It should be notedthat recently, the EPA has expressed concern regarding the use of route-to routeextrapolation due to the uncertainties associated with this methodology.

In conclusion, based on the review it was determined that the refinery streamswere not similar in composition to any of the surrogate fractions. Furthermore, ofthe available data, only two subchronic inhalation studies would be consideredappropriate by the US EPA for the development of oral RfDs.

101

I. INTRODUCTION

A. PURPOSE OF THE DOCUMENT

The review of the American Petroleum Institute’s data on selected refinery streamswas undertaken in order to determine:

• whether, based on composition, any of the refinery streams aresimilar in overall composition to the carbon ranges of the surro-gate fractions

• whether any of the toxicity studies on the refinery streams can beused to develop oral reference doses (RfDs)

II. EPA METHODOLOGY FOR THE DEVELOPMENT OF ORAL REFERENCE DOSES (RfDs)

The US EPA issued The Risk Assessment Guidelines of 1986 in which methods fordeveloping reference dose (RfD) values were given. Since then, ProposedGuidelines for Neurotoxicity; Guidelines for Developmental Toxicity RiskAssessment; and Guidelines for Reproductive Toxicity Risk Assessment have beenpublished, which also discuss the development of RfDs. In addition, the IRIS data-base provides guidance for developing RfD values in Background Document 1(Reference Dose: Use in Health Risk Assessment), last revised March 15, 1993.Information on the development and use of RfDs is also provided in the RiskAssessment Guidance for Superfund Volume 1 Human Health Evaluation. Areview of the available information shows that US EPA’s methods for determiningthe RfDs remains unchanged.

A. DEFINITION OF THE REFERENCE DOSE (RfD)

The RfD is “an estimate (with uncertainty spanning perhaps an order of magni-tude) of daily exposure to the human population, including sensitive subgroups,that is likely to be without appreciable risk of deleterious effects during a lifetime”(USEPA, 1989). The RfD is used to evaluate potential noncarcinogenic effects ofexposure to a given compound. It is not used to evaluate carcinogenic endpoints.The RfD is operationally derived from a no-observed-adverse-effect-level (NOAEL)by application of uncertainty factors (UFs) that reflect various types of data setsused to estimate a reference value and application of a modifying factor (MF),which reflects the completeness of the database.

B. APPROPRIATE DATA FOR DEVELOPMENT OF AN ORAL RfD

The first step in developing an RfD is to choose a critical study and determine theNOAEL. The NOAEL is the highest dose at which no adverse effects are observed.If a NOAEL is not available, a lowest-observed-adverse-effect-level (LOAEL) can beused; however, this adds an additional uncertainty factor into the equation. Themost appropriate source of the NOAEL for the oral RfD (or LOAEL) is from a

102

chronic oral study. If there is no chronic oral data, subchronic oral data can alsobe used, but this also adds another level of uncertainty into the derivation of theRfD. In some cases, chronic and subchronic inhalation studies can be utilized inthe development of oral RfDs when there are no oral data available. However, thisis not common practice because there is a great deal of uncertainty surroundingthe use of inhalation data in this respect.

Most other toxicity data (i.e., dermal, acute, or genotoxic) are not recommendedfor use in the development of oral RfDs. Acute oral LD50s have been used to develop“tentative” RfDs, which represent a dose that the “true” RfD will fall below. TheseRfDs are calculated by taking the oral LD50 and dividing it by 100,000 or 1,000,000.

The use of dermal data to develop oral RfDs is an area currently being reviewedby the US EPA. The biggest concern centers around the lack of data on theamount of the compound absorbed through the skin which causes the toxic end-point. Because this is an ongoing issue with US EPA, there is no regulatory guid-ance on the methodology to be used in the calculation process.

In a published document by Ryer-Powder and Sullivan (1994), an oral RfD wasderived from a dermal carcinogenicity study. In the development of the RfD, anabsorption factor of 1% was incorporated into the equation. However, no datawere provided that support the use of this extremely conservative value.Information on absorption of various compounds through the skin is available inthe literature. In a report on the bioavailability of petroleum constituents, defaultdermal absorption values from soil were recommended for benzo(a)pyrene,benzene, toluene, and xylene of 3 - 30%, 10%, 10%, and 75%, respectively(Brainard and Beck, 1992). Another report investigated the absorption of radio-labeled benzo(a)pyrene from lubricants of different viscosities and found a rangeof 18 to 23% for dermal absorption (CONCAWE, 1990). More reasonable esti-mates of absorption can be obtained from these studies.

C. DERIVATION OF AN ORAL RfD

The RfD is calculated using the following equation:

RfD = NOAEL (or LOAEL)/(UF x MF)

where the RfD is expressed in mg/kg/day; the NOAEL (or LOAEL) representsa critical effect; the uncertainty factor (UF) can range from 1 to 10,000; and themodifying factor (MF) can range from 1 to 10 based on the completeness of thedata set.

D. UNCERTAINTY AND MODIFYING FACTORS

Following are explanations of the different uncertainty factors used in the deriva-tion of RfDs:

• Use a 10-fold factor when extrapolating from valid experimentalresults in studies using prolonged exposure to average healthyhumans. This factor is intended to account for the variation insensitivity among the members of the human population and isreferenced by the EPA as “10H.”

103

• Use an additional 10-fold factor when extrapolating from validresults of long-term animal studies when results of humansstudies are either not available or inadequate. This factoraccounts for the uncertainty involved in extrapolating fromanimal data to humans and is referenced by the EPA as “10A.”

• Use an additional 10-fold factor when extrapolating from lessthan chronic results on experimental animals when there are nouseful long-term human data. This factor is intended to accountfor the uncertainty involved in extrapolating from less thanchronic NOAELs to chronic NOAELs and is referenced by theEPA as “10S.”

• Use an additional 10-fold factor when deriving an RfD from aLOAEL, instead of a NOAEL. This factor is intended to accountfor the uncertainty involved in extrapolating from LOAELs toNOAELs and is referenced by the EPA as “10L.”

The modifying factor is an additional uncertainty factor and is applied based onthe strength of the database and professional judgment. The MF can range from1 to 10.

III. DESCRIPTION OF THE API DATA ON REFINERY STREAMS

A. CONTENT OF API DATA ON REFINERY STREAMS

During the past 15 years, the API has conducted a series of toxicological studies onselected refinery streams. The streams which were tested represent high volumerefinery processes. These streams vary widely in composition and range from mate-rials in the naphtha range having carbon numbers predominantly in the C4 to C11

range (light ends) to heavy vacuum residuums which have carbon numbers pre-dominantly greater than C34. The names of the refinery streams, their API codenumbers, and description of their composition (i.e., predominant carbon numberrange, percent aliphatics and aromatics) are provided in Table C-1. In order todetermine their toxicity, a battery of toxicity tests was carried out on each stream.In addition to acute toxicity testing, some of the streams were tested to evaluatetheir genotoxic potential (see Table C-2). In some cases, subchronic dermal andinhalation studies as well as chronic dermal studies were also conducted (see TableC-3). However, it should be noted that no subchronic or chronic oral studies werecarried out on any of the streams.

B. EVALUATION OF GENETOX DATA

Genotoxicity assays are used to assess the potential of a test article to cause muta-genicity, clastogenicity (chromosome damage), or DNA damage in either in vitro orin vivo test systems. The results of these assays can assist in the assessment of thecarcinogenicity potential of a compound. Typically, compounds that are carcino-genic are also genotoxic. So, conversely, compounds that are genotoxic couldpotentially go on to produce cancer.

104

105

TABLE C-1. Description of API Refinery Streams

API Refinery Predominant Carbon Percent PercentStream Code Name Number Range Aliphatic Aromatic

78-02 Home heating oil Medium catalytic cracked stock (30%) C10 - C24

a NAb NAb

78-03 Home heating oil Low catalytic cracked stock (10%) C10 - C24

a NAb NAb

78-04 Home heating oil High catalytic cracked stock (50%) C10 - C22

a NAb NAb

78-05 Naphthenic base stock C15 - C30 76.2 23.8

78-09 Paraffinic base stock C15 - C25a 89.8 10.2

78-10 Paraffinic base stock > C19a 86.2 13.8

79-01 Naphthenic base stock C20 - C50 62.3 37.7

79-03 Paraffinic base stock C20 - C50 71.9 28.1



81-03 Light catalytically cracked naphtha C4 - C11 91.4 8.6

81-04 Light catalytically cracked naphtha C4 - C11 79.7 20.3

81-07 Hydrodesulfurized kerosine C9 - C16 82 18

81-08 Sweetened naphtha C4 - C12 96 4

81-09 Hydrodesulfurized middle distillate C11 - C25 75 25

81-10 Hydrodesulfurized middle distillate C11 - C25 69.1 30.9

81-13 Vacuum residuum > C34 NAb NAb

81-14 Vacuum residuum > C34 29.5 34.7

81-15 Catalytically cracked clarified oil > C20 8 58.3

83-01 Home heating oil Light catalytic cracked stock (10%) C10 - C19

a 75.6 24.4


a 70.5 29.5


a 72.7 27.3

83-04 Light catalytically reformed naphtha C5 - C11 60.5 39.5

83-05 Full range catalytically reformed naphtha C4 - C12 37.5 62.5

83-06 Heavy catalytically reformed naphtha C7 - C12 8.7 91.3

83-07 Light catalytically cracked distillate C9 - C25 27.6 72.4

83-08 Light catalytically cracked distillate C9 - C25 31.7 68.3

83-09 Straight run kerosine C9 - C16 82 18

83-11 Straight run middle distillate C11 - C20 78.8 21.2

83-12 Hydrotreated light naphthenic distillate C15 - C30 67.3 31.9

83-15 Hydrotreated heavy naphthenic distillate C20 - C50 53.1 46.9

83-16 Light paraffinic distillate solvent extract C15 - C30 39.1 60.9

83-18 Heavy catalytically cracked naphtha C6 - C12 36.2 63.8

83-19 Light alkylate naphtha C7 - C10 99.9 <0.1

84-01 Light paraffinic distillate C15 - C30 79.1 20.9

84-02 Heavy thermally cracked naphtha C6 - C12 84.3 15.7

85-01 Stoddard solvent C9 - C11 85.5 14.5aValue is estimated because data are not provided.bNo data are available for this parameter.

106

TABLE C-2. Genotoxicity Data Available for Selected Refinery Streamsa

API In vitro In vivo Refinery Mouse Rat Bone Modified In vivo In vitroStreamsb Lymphoma Marrow Ames Ames SCEc SCEc

78-0278-0378-04 + +f E78-05 - - - -78-09 Ed - - -78-10 E - - -79-01 - - - -79-03 E + - -79-04 E - - -79-05 E - - -81-0381-04 1) E (w A)e

- (w/o A)2) - -

81-07 - - - + (w A)- (w/o A)

81-08 - -81-09 -81-10 - - E (w A)

- (w/o A)81-1481-15 + + (w A)

- (w/o A)83-0183-0283-0383-04 - -83-05 + (w A)

- (w/o A) -83-06 1)+ (w A)

- (w/o A)2) E -

83-07 + (w A)- (w/o A) - + E

83-08 + -83-09 E (w A)

+ (w/o A) -83-11 1) + (w A)

- (w/o A)2) +

83-12 +83-15 -83-16 +83-18 +83-19 - -84-01 + (w A)

- (w/o A)84-02 +85-01 + -a Descriptions of the genotoxicity assays can be found in Table C-4.b Data on the composition of the refinery streams can be found in Table C-1.c Sister chromatid exchange d Equivocal results e Activation f Results questionable

107

TABLE C-3. Subchronic and Chronic Toxicity Data Available for Selected Refinery Streams

Subchronic Chronic___________________________________ ___________________________________API RefineryStreamsa Oral Inhalation Dermal Oral Inhalation Dermal

78-02 X

78-03 X

78-04 X X

78-05 X X

78-09 X X

78-10 X X

79-01 X X

79-03 X X

79-04 X

79-05 X X

81-03 X X

81-04 X

81-07 X X X

81-08 X

81-09 X X X

81-10 X X X

81-13 X

81-14 X

81-15 X

83-01 X

83-02 X

83-03 X

83-04 X

83-05 X

83-06 X X

83-07 X

83-08 X

83-09 X X

83-11 X X

83-12 X X

83-15 X

83-16 X X

83-18 X X

83-19 X X

84-01 X X

84-02 X X

85-01 XaData on the composition of refinery streams can be found in Table C-1.

With the API refinery streams, there have been several different genotoxicityassays performed to assess the potential for these streams to cause mutagenicity orclastogenicity (chromosomal damage) in both in vivo and in vitro test systems (seeTable C-4). However, there have been no assays conducted which look at the poten-tial for these streams to cause DNA damage. In looking at the results of these assays(see Table C-2), the majority of the results were either negative or equivocal.Equivocal results mean that the results of the assay were uncertain and a conclusionon genotoxicity could not be made. There were some positive results for severalstreams, but these results were not conclusive because either only one genotoxicityassay was performed or there were mixed results on several genotoxicity assays. Forexample, API refinery stream 83-12 (hydrotreated light naphthenic distillate) hadpositive results in an in vitro mouse lymphoma assay. However, this was the only assayperformed on this stream and there was no other supporting evidence.

In the OECD guidelines for genetic toxicology testing, it is recommended that abattery of tests be performed to assess the genotoxic potential of a compoundbecause the results from one test are inconclusive and have low confidence. Forseveral of the API refinery streams, there were multiple genotoxicity assays andthere were both positive and negative results obtained. For example, with APIrefinery stream 79-03 (paraffinic base stock), two of the assays were negative, onewas equivocal, and one assay had positive results. The interpretation of theseresults would be equivocal because of the mixed results. Further testing would beneeded to ascertain the genotoxic potential of this refinery stream.

Genotoxicty tests are not typically used by the US EPA in the development ofRfDs. As mentioned previously, data from these types assays are typically used toassess the potential of compound to be carcinogenic. Because the majority of thegenotoxicity data for the API refinery streams was negative, this indicates a lowpotential of the streams to cause genotoxicity and a low concern for carcinogenicpotential of the streams.

C. EVALUATION OF SUBCHRONIC AND CHRONIC DATA

As stated above, the API conducted a number of subchronic inhalation and dermalstudies as well as some chronic dermal carcinogenicity studies on selected refinerystreams (Table C-3). In order to develop oral RfDs, the EPA currently recommendsthat these values be developed from chronic oral or inhalation studies.Alternatively, subchronic oral or subchronic inhalation studies can be used.However, to date, dermal studies (either chronic or subchronic) have not beenused by the EPA to develop oral RfDs for petroleum hydrocarbons due to theuncertainty associated with the amount test material absorbed and problems withthe protocols (e.g., studies do not follow TSCA or OECD guidelines).Furthermore, in the majority of cases the only effects observed in these dermalstudies are local effects such as erythema and/or edema. Repeated dermal expo-sure protocols with severely irritating materials are not representative of humanexposure scenarios. In those studies where systemic effects were evaluated, theywere typically not observed. Thus, the use of dermal studies for the developmentof oral reference doses remains questionable.

108

IV. ANALYTICAL COMPOSITION OF REFINERY STREAMS

Although analytical data are available for each of the streams that were tested, theextent of the compositional analysis varies depending on the specific stream. Forexample, detailed GC-MS data are available for each of the nine naphtha streams.From this data, the weight percent of individual hydrocarbons with differingcarbon numbers can be determined (e.g., API 81-03, API 84-01, Attachment I).However, in other cases, the only analytical data available on the stream are theinformation from the distillation curve for the material (i.e., the volume percentdistilled off at differing temperatures) and the total percent of saturates, olefinsand aromatics in the stream. Using the distillation data, the carbon numbers of thecompounds distilling off at different temperatures can be estimated. If one thenassumes that each boiling range has the same percentage of aliphatics and aro-matics, the percent of aliphatics and aromatics in the various fractions can be esti-mated (e.g., API 81-07, Attachment I). However, it must be recognized that theseassumptions may, at times, result in either significant overestimates or underesti-mates of these fractions.

109

TABLE C-4. Description of Genotoxicity Tests Conducted on API Refinery Streams

Genotoxicity Test Objective

Mutagenic Assays

In vitro mouse lymphoma Evaluate test article for its ability to induce forwardmutation in the mouse lymphoma cell line. Aforward mutation alters the gene and inactivatesit. With this type of mutation, there is a detectablechange in appearance or structure.

Ames and modified Ames Evaluate the test article for mutagenic activity in abacterial mutation system , Salmonella, with andwithout a mammalian S9 activation component.

Clastogenic (chromosome damage) Assays

In vivo rat bone marrow Evaluate test article for its ability to induce chro-mosome aberrations, which are changes in chro-mosome structure, in somatic (body) cells. First,animals are treated with the test article and thenthe cells are removed and analyzed.

In vivo sister chromatid exchange (SCE) Evaluate the ability of the test article to induceSCEs in rodent bone marrow, spleen, or sper-matagonia cells. An SCE is when segments of twochromatids of a chromosome are exchanged.First, animals are treated with the test article andthen the cells are removed and analyzed.

In vitro SCE Evaluate the ability of the test article to induceSCEs in Chinese hamster ovary (CHO) cells, withand without metabolic activation.

For the purpose of illustration, the composition of API Stream 81-03 (LightCatalytic Cracked Naphtha) which was determined by GC-MS and API 81-07(Hydrodesulfurized Kerosine) whose composition was determined based on distil-lation curve data are presented in tabular form in Tables C-5 and C-6, respectively.In order to better compare these data to the surrogate fractions, simpler tableswere prepared from the information presented in Tables C-5 and C-6. As shown inTables C-7 and C-8, the total weight percent of compounds with carbon numbersin the various ranges (both aliphatic and aromatic) were added together. Forexample, as shown in Table C-3, API 81-03 contains 30.1% C5 aliphatics and 29.1%C6 aliphatics for a total of 59.2% aliphatics in the C5 - C6 range (Table C-5), etc.

V. DEVELOPMENT OF RfDs FOR SELECTED REFINERY STREAMSBASED ON THE BEST AVAILABLE CHRONIC OR SUBCHRONIC DATA

A. CHRONIC DATA

For certain streams, the only data available are from 2-year chronic dermal car-cinogenicity studies. Although one can attempt to develop oral RfDs from suchstudies, it is doubtful that this is appropriate for the following reasons:

• Only a single dose level is used in these studies. Thus, they donot provide a dose response assessment and therefore an accu-rate determination of toxicity is not possible.

• When tumors are observed, they occur only at the site of appli-cation (i.e., skin tumors).

• Systemic effects are typically not evaluated.

• Protocols not consistent with TSCA and OECD guidelines.

Based on the reasons stated above, such data should not be used to develop anoral RfD, which will protect against systemic effects. Therefore, oral RfDs were notdeveloped from these studies.

B. DEVELOPMENT OF RFDs FROM SUBCHRONIC INHALATION AND SUBCHRONICDERMAL STUDIES

1. Subchronic Inhalation Studies.

As shown in Table C-3, subchronic inhalation studies were conducted on five refin-ery streams. Of these five studies, only two were appropriate for the developmentof an oral RfD. These two studies were API 81-03 (Light Catalytic CrackedNaphtha) and 85-01 (Stoddard Solvent); both were 13-week inhalation studies withmultiple dose levels. The remaining three subchronic inhalation studies (API 81-07 Hydrodesulfurized Kerosene, 81-09 and 81-10 Hydrodesulfurized MiddleDistillate) were inappropriate because they were conducted using a single doselevel and hence no dose response information was available. The examples of thedevelopment of oral RfDs from API 81-03 (Light Catalytic Cracked Naphtha) and85-01 (Stoddard Solvent) are shown on the following pages.

110

111

TAB

LE C

-5.

Ligh

t C

atal

ytic

Cra

cked

Nap

htha

(AP

I 81-

03)

wt

%w

t %

wt

%w

t %

Alip

hati

cAr

omat

icAl

ipha

tic

Arom

atic

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

GC

/MS

ID

C#

(GC

/MS

)C

#(G

C/M

S)

BP

R

ange

BP

Ran

geB

P R

ange

Ben

zene

Tolu

ene

Et.b

enze

neXy

lene

snC

6nC

7nC

9N

apht

hale

neP

yren

e(C

16

)P

NAs

C4s

2.4

>nC

3-<

/=nC

41.

2

C5s

30.1

>nC

4-<

/=nC

521

.6

C6s

29.1

2.9

>nC

5-<

/=nC

628

.22.

871.

9

C7s

16.8

4.7

>nC

6-<

/=nC

722

.32.

94.

660.

69

C8s

5.8

3.8

>nC

7-<

/=nC

810

.24.

70.

673.

17

C9s

1.3

1.4

>nC

8-<

/=nC

92.

23.

80.

09

C10

s0.

210.

26>

nC9-

</=

nC10

0.23

1.3

0.1

C11

s0.

140.

1>

nC10

-</=

nC11

0.24

0.25

C12

s>

nC11

-</=

nC12

0.18

8613

8613

HC

Typ

e/S

umm

ed

99<

0.00

01~

0.1

99 HC

Typ

e/M

S90

10H

C T

ype/

D13

1991

9

112

TAB

LE C

-5.

Con

tinue

d

D-1

319

Vol %

Sat

urat

es56

Ole

fins

35Ar

omat

ics

9-<

/=nC

646

4.5

>nC

6-<

/=nC

727

2.7

>nC

7-<

/=nC

812

1>

nC8-

</=

nC9

>nC

9-<

/=nC

105

0.5

>nC

10-<

/=nC

11>

nC11

-</=

nC12

D-8

6 D

ISTI

LLAT

ION

DAT

A:

vol %

Dis

tille

d of

f:de

gFde

gC~

~~

C#

IBP

9334

nC5

5%10

641

10%

113

4520

%12

351

30%

133

5640

%14

362

50%

153

67nC

660

%16

876

70%

185

8580

%20

898

nC7

90%

244

118

nC8

95%

280

138

nC8

EP(9

9%)

350

177

nC10

D-1

319

Vol %

Sat

urat

es56

Ole

fins

35Ar

omat

ics

9

API G

ravi

ty:

70D

ensi

ty:

0.70

05

113

TAB

LE C

-6.

Hyd

rode

sulfu

rized

Ker

osen

e (A

PI 8

1-07

)D

etai

led

hydr

ocar

bon

data

not

ava

ilabl

e, t

hus

the

tabl

e w

ith C

# d

istr

ibut

ion

and

BP

rang

e ca

nnot

be

gene

rate

d

wt

%w

t %

wt

%w

t %

Alip

hati

cAr

omat

icAl

ipha

tic

Arom

atic

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

GC

/MS

ID

C#

(GC

/MS

)C

#(G

C/M

S)

BP

R

ange

BP

Ran

geB

P R

ange

Ben

zene

Tolu

ene

Et.b

enze

neXy

lene

snC

6nC

7nC

9N

apht

hale

neP

yren

e(C

16

)P

NAs

C4s

>nC

3-<

/=nC

4

C5s

>nC

4-<

/=nC

5

C6s

>nC

5-<

/=nC

6

C7s

>nC

6-<

/=nC

70.

1

C8s

>nC

7-<

/=nC

8

C9s

>nC

8-<

/=nC

90.

80.

13

C10

s>

nC9-

</=

nC10

C11

s>

nC10

-</=

nC11

C12

s>

nC11

-</=

nC12

HC

Typ

e/S

umm

ed0.

00.

00.

00.

0

00.

0002

~0.

9

0 HC

Typ

e/M

S71

29H

C T

ype/

D13

1978

22

114

TAB

LE C

-6.

Con

tinue

d

D-1

319

Vol %

Sat

urat

es77

.3O

lefin

s0.

5Ar

omat

ics

22.2

API G

ravi

ty:

41.8

Den

sity

: 0.

8157

D-8

6 D

isti

llati

on D

ata:

vol %

Dis

tille

d of

f:de

gFde

gC~

~~

C#

IBP

310

154

nC9

5%38

219

4nC

1110

%39

520

220

%40

920

930

%42

021

5nC

1240

%42

922

150

%43

622

460

%44

322

870

%45

223

3nC

1380

%46

424

090

%48

024

995

%49

325

6nC

14EP

(99.

5%)

533

278

nC15

Assu

me

that

eac

h bo

iling

ran

ge h

as t

he s

ame

% o

f al

ipha

tics

and

% o

f ar

omat

ics:

(78

vol%

)(2

2 vo

l%)

vol %

vol %

Alip

hati

cAr

omat

icB

P

Ran

geB

P R

ange

BP

Ran

ge

>nC

8-<

/=nC

90

0>

nC9-

</=

nC10

>nC

10-<

/=nC

113.

91.

1>

nC11

-</=

nC12

19.5

5.5

>nC

12-<

/=nC

1331

.28.

8>

nC13

-</=

nC14

19.5

5.5

>nC

14-<

/=nC

153.

51

115

TABLE C-8. API SAMPLE 81-07(Hydrodesulfurized Kerosine)

Wt% Aliphatic Wt% Aromatic

C4

C5-C6

C7-C8

C9-C10

C11-C12 23.4 6.6

C13-C16 54.2 14.4

C17+ -

TABLE C-7. API SAMPLE 81-03(Light Catalytic Cracked NAPHTHA)


C4 2.4

C5-C6 59.2 2.9

C7-C8 22.6 8.5

C9-C10 1.5 1.7

C11-C12 0.14 0.1

C13-C16 - -

C17+ -

2. Subchronic Dermal Studies

As shown in Table C-3, subchronic dermal studies were conducted on 30 refinerystreams. However, absorption data were not available for any of the these studies.Thus, a default assumption would be required to estimate the amount of materialabsorbed. Because of the uncertainties inherent in such default assumptions, theuse of dermal data to develop oral RfDs remains highly controversial and is cur-rently not accepted by the USEPA. Therfore, oral RfDs were not developed fromthe dermal data on these refinery streams.

VI. CONCLUSIONS

The API Refinery Stream Data cannot be used to develop oral RfDs for the follow-ing reasons:

• The composition of the refinery streams does not adequatelymatch the equivalent carbon ranges of the surrogate fractions.

• The chronic dermal carcinogenicity studies were conductedwith a single dose and systemic effects were not evaluated.

• The development of oral RfDs from the two multidose sub-chronic inhalation studies required route-to-route extrapola-tion; although currently acceptable, route-to-route extrapolationis not recommended by the USEPA.

• Absorption data were not available for any subchronic dermalstudy so a default value (50%) was used; due to the uncertaintiesinherent in such default assumptions, the use of dermal data todevelop oral RfDs remains controversial and is currently notaccepted by the USEPA.

116

117

EXAMPLE 1.API 81-03

Light Catalytical Cracked Naptha

In this study, rats were exposed to 1510, 2610 or 4520 ppm for five days/week for13 weeks. There was a dose-related increase in liver weights for both males andfemales in the high-level group. These liver weight changes were associated witha trace severity of cellular hypertrophy. Thus, 2610 ppm was considered to be theNOAEL in this study. In order to calculate an oral RfD from this study, the inhala-tion NOAEL must first be converted to an equivalent oral dose.

DEVELOPMENT OF AN ORAL RFD FROM SUBCHRONIC INHALATION STUDY:

1. Convert inhalation NOAEL to Oral NOAEL

• Inhalation NOAEL = 2610 ppm = 8753 mg/m3 (MW = 82)

• Daily exposure period = 6 hr/24 hr

• Assumed daily respiratory volume for a 0.31 kg rat = 0.2 m3 /day

• Conversion of 5 day/week dosing regimen to 7 day/week con-tinuous exposure = 5/7

• Estimated ratio of inhaled dose systemically absorbed = 0.5(Pepelko and Withey 1985)

Equivalent Oral Dose =

8753 mg/m3 x 6hr/24 hr x 0.2 m3/day x 5d/7d x 0.5 = 520 mg/kg/day0.3 kg

Calculation of RfD:

Equivalent Oral DoseUncertainty Factor

Uncertainty Factor = 1000 (to account for use of subchronic study, variationwithin species, variation between species).

520 mg/kg/day = 0.521 mg/kg/day1000

118

EXAMPLE 2API 85-01

Stoddard Solvent

Development of an oral RfD from a 13-week inhalation toxicity study in the rat(animals dosed 6 hr/day, 5 days/week x 13 weeks - Tox. Appl. Pharmacol. 32:282-297, 1975).

1. Convert inhalation NOAEL to oral NOAEL

• Inhalation NOAEL = 1.9 mg/L = 1900 mg/m3

• Daily exposure period = 6 hr/24 hr

• Assumed daily respiratory volume for a 0.3 kg rat = 0.2 m3/day

• Conversion of 5 day/week dosing regimen to 7 day/week con-tinuous exposure = 5/7

• Estimation of ratio of inhaled dose systemically absorbed = 0.5

Equivalent Oral Dose:

1900 mg/m3 x 6 hr/24hr x 0.2m3/day x 5 d/7 d x 0.5 = 113 mg/kg/day0.3 kg

Calculation of Oral RfD: (uncertainty factor = 1000)

113 mg/kg/day = 0.11 mg/kg/day1000

REFERENCES

API Health Environ. Sci. Dep. Rep.

Brainard, J. and Beck, B.D. (1992). A review of bioavailability of petroleum constituents. Submitted tothe Association of the Environmental Health of Soils. Presentation at 1992 West Coast Soils andGroundwater Conference.

Carpenter, C.P., Kincead, E.R., Geary, D.L., Sullivan, L.J., and King, J.M. (1975). Petroleum hydrocarbontoxicity studies III. Animal and human response to vapors of Stoddard solvent. Tox. Appl. Pharmacol.32:282-297.

CONCAWE (1990). Factors Affecting the Skin Penetration and Carcinogenic Potency of PetroleumProducts Containing Polycyclic Aromatic Hydrocarbons. Report No. 90/55.

IRIS CD-Rom, Vol. 27. Expiration: January 31, 1996.

Pepelko, W.E. and Withey, J.R. (1985). Methods for route-to-route extrapolation of dose. Tox. Ind.Health 1:153-175.

Ryer-Powder, J.E., and Sullivan, M.J. (1994). Chapter 2: Update on the Derivation of an Oral ReferenceDose for Diesel Fuel No. 2. In Principles and Practices for Diesel Contaminated Soils, Vol III, (P.T.Kostecki; E.J. Calabrese and C.P.L Barkan, Eds.). Amherst, MA, Amherst Sc. Publ.

USEPA (1987). The Risk Assessment Guidelines of 1986 (EPA600/08-87-045), August.

USEPA (1989). Risk Assessment Guidance for Superfund Volume 1 Human Health Evaluation Manual.(EPA/540/1-89/002), December.

USEPA (1990) Review Draft, Interim Methods for Development of Inhalation Reference Concentrations(EPA/600/8-90/006A), August.

USEPA (1991). Guidelines for Developmental Toxicity Risk Assessment, Federal Register Vol. 56 No. 234,December 5.

USEPA (1994). Review Draft Guidelines for Reproductive Toxicity Risk Assessment (EPA600.AP.94.001),February.

USEPA (1995). Proposed Guidelines for Neurotoxicity, Federal Register Vol. 60, No. 192, October 4,1995.

119

ATTACHMENT I

Composition Data on Selected API Refinery Streams

123

Tabl

e I-

1. L

ight

Cat

alyt

ic C

rack

ed N

apht

ha (

API 8

1-03

)

wt

%w

t %

wt

%w

t %

Alip

hati

cAr

omat

icAl

ipha

tic

Arom

atic

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

GC

/MS

ID

C#

(GC

/MS

)C

#(G

C/M

S)

BP

R

ange

BP

Ran

geB

P R

ange

Ben

zene

Tolu

ene

Et.b

enze

neXy

lene

snC

6nC

7nC

9N

apht

hale

neP

yren

e(C

16

)P

NAs

C4s

2.4

>nC

3-<

/=nC

41.

2

C5s

30.1

>nC

4-<

/=nC

521

.6

C6s

29.1

2.9

>nC

5-<

/=nC

628

.22.

871.

9

C7s

16.8

4.7

>nC

6-<

/=nC

722

.32.

94.

660.

69

C8s

5.8

3.8

>nC

7-<

/=nC

810

.24.

70.

673.

17

C9s

1.3

1.4

>nC

8-<

/=nC

92.

23.

80.

09

C10

s0.

210.

26>

nC9-

</=

nC10

0.23

1.3

0.1

C11

s0.

140.

1>

nC10

-</=

nC11

0.24

0.25

C12

s>

nC11

-</=

nC12

0.18

8613

8613

HC

Typ

e/S

umm

ed

99<

0.00

01~

0.1

99 HC

Typ

e/M

S90

10

HC

Typ

e/D

1319

919

124

Tabl

e I-

1. C

ontin

ued

D-1

319

Vol %

Sat

urat

es56

Ole

fins

35Ar

omat

ics

9

API G

ravi

ty:

70D

ensi

ty:

0.70

05

Assu

me

that

eac

h bo

iling

ran

ge h

as t

he s

ame

% o

f al

ipha

tics

and

% o

f ar

omat

ics:

(91

vol%

)(9

vol

%)

vol %

vol %

Alip

hati

cAr

omat

icB

P

Ran

geB

P R

ange

BP

Ran

ge

>nC

3-<

/=nC

40

0>

nC4-

</=

nC5

00

>nC

5-<

/=nC

646

4.5

>nC

6-<

/=nC

727

2.7

>nC

7-<

/=nC

812

1>

nC8-

</=

nC9

>nC

9-<

/=nC

105

0.5

>nC

10-<

/=nC

11>

nC11

-</=

nC12

D-8

6 D

ISTI

LLAT

ION

DAT

A:

vol %

Dis

tille

d of

f:de

gFde

gC~

~~

C#

IBP

9334

nC5

5%10

641

10%

113

4520

%12

351

30%

133

5640

%14

362

50%

153

67nC

660

%16

876

70%

185

8580

%20

898

nC7

90%

244

118

nC8

95%

280

138

nC8

EP(9

9%)

350

177

nC10

125

Table I-2. API Sample 81-03 (Light Catalytic Cracked Naphtha)


C4 2.4

C5-C6 59.2 2.9

C7-C8 22.6 8.5

C9-C10 1.5 1.7

C11-C12 0.14 0.1

C13-C16 - -

C17+ -

126

Tabl

e I-

3. S

todd

ard

Sol

vent

, M

iner

al S

pirit

s (A

PI 8

5-01

)

wt

%w

t %

wt

%w

t %

Alip

hati

cAr

omat

icAl

ipha

tic

Arom

atic

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

GC

/MS

ID

C#

(GC

/MS

)C

#(G

C/M

S)

BP

R

ange

BP

Ran

geB

P R

ange

Ben

zene

Tolu

ene

Et.b

enze

neXy

lene

snC

6nC

7nC

9N

apht

hale

neP

yren

e(C

16

)P

NAs

C4s

>nC

3-<

/=nC

4

C5s

>nC

4-<

/=nC

5

C6s

>nC

5-<

/=nC

6

C7s

>nC

6-<

/=nC

7

C8s

0.21

0.52

>nC

7-<

/=nC

80.

13N

DN

D0.

030.

49N

DN

D

C9s

10.4

6.4

>nC

8-<

/=nC

99.

10.

525.

3

C10

s36

.86.

5>

nC9-

</=

nC10

35.6

6.0

0.61

C11

s27

.42.

3>

nC10

-</=

nC11

28.5

5.5

C12

s8.

10.

49>

nC11

-</=

nC12

9.7

3.7

C13

s0.

44>

nC12

-</=

nC13

0.52

0.27

HC

Typ

e/S

umm

ed83

1683

16

99<

0.00

01~

0.7

99 HC

Typ

e/M

S83

.516

.5

HC

Typ

e/D

1319

83.6

16.4

127

Tabl

e I-

3. C

ontin

ued

D-8

6 D

ISTI

LLAT

ION

DAT

A:

vol %

Dis

tille

d of

f:de

gFde

gC~

~~

C#

IBP

321

161

>nC

95%

327

164

10%

329

165

20%

332

167

30%

337

169

40%

342

172

50%

345

174

nC10

60%

349

176

70%

354

179

80%

361

183

90%

374

190

95%

385

196

nC11

EP(9

8.5%

)40

420

7<

nC12

Assu

me

that

eac

h bo

iling

ran

ge h

as t

he s

ame

% o

f al

ipha

tics

and

% o

f ar

omat

ics:

(83.

5 vo

l%)

(16.

5 vo

l%)

vol %

vol %

Alip

hati

cAr

omat

icB

P

Ran

geB

P R

ange

BP

Ran

ge

>nC

3-<

/=nC

40

0>

nC4-

</=

nC5

>nC

5-<

/=nC

6>

nC6-

</=

nC7

>nC

7-<

/=nC

8>

nC8-

</=

nC9

>nC

9-<

/=nC

1042

.08.

3>

nC10

-</=

nC11

37.6

7.4

>nC

11-<

/=nC

124.

20.

83

D-1

319

Vol %

Sat

urat

es83

.5O

lefin

s<

0.1

Arom

atic

s16

.5

API G

ravi

ty:

48.3

Den

sity

: 0.

7870

128

Table I-4. API Sample 85-01 (Stoddard Solvent)


C4

C5-C6

C7-C8 0.21 0.52

C9-C10 47.2 12.9

C11-C12 35.5 2.8

C13-C16 0.44 -

C17+ -

TABLE I-5. API Sample 83-15 (Hydrotreated Heavy Naphthenic Distillate)


C4

C5-C6

C7-C8

C9-C10

C11-C12

C13-C16

C17+ (c20+) 58.7 37.2

129

Tabl

e I-

6. L

ight

Par

rafin

ic D

istil

late

(AP

I 84-

01)

wt

%w

t %

wt

%w

t %

Alip

hati

cAr

omat

icAl

ipha

tic

Arom

atic

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

GC

/MS

ID

C#

(GC

/MS

)C

#(G

C/M

S)

BP

R

ange

BP

Ran

geB

P R

ange

Ben

zene

Tolu

ene

Et.b

enze

neXy

lene

snC

6nC

7nC

9N

apht

hale

neP

yren

e(C

16

)P

NAs

C4s

2.2

>nC

3-<

/=nC

40.

72

C5s

19.6

>nC

4-<

/=nC

513

.9

C6s

19.8

0.9

>nC

5-<

/=nC

618

.40.

941.

18

C7s

14.3

5.0

>nC

6-<

/=nC

718

.70.

94.

970.

6

C8s

9.4

8.9

>nC

7-<

/=nC

811

.85.

01.

647.

29

C9s

5.7

9.1

>nC

8-<

/=nC

97.

68.

90.

39

C10

s1.

91.

7>

nC9-

</=

nC10

2.4

8.3

0.04

C11

s0.

9>

nC10

-</=

nC11

0.9

2.4

C12

s>

nC11

-</=

nC12

HC

Typ

e/S

umm

ed74

2674

26

99nd

~0.

02

100

HC

Typ

e/M

S78

22

HC

Typ

e/D

1319

7921

130

Tabl

e I-

6. C

ontin

ued

D-1

319

Vol %

Sat

urat

es48

.4O

lefin

s30

.6Ar

omat

ics

21

API G

ravi

ty:

60.4

Den

sity

: 0.

7366

Assu

me

that

eac

h bo

iling

ran

ge h

as t

he s

ame

% o

f al

ipha

tics

and

% o

f ar

omat

ics:

(79

vol%

)(2

1 vo

l%)

vol %

vol %

Alip

hati

cAr

omat

icB

P

Ran

geB

P R

ange

BP

Ran

ge

>nC

3-<

/=nC

40

0>

nC4-

</=

nC5

>nC

5-<

/=nC

616

4.2

>nC

6-<

/=nC

724

6.3

>nC

7-<

/=nC

816

4.2

>nC

8-<

/=nC

916

4.2

>nC

9-<

/=nC

104.

01.

1>

nC10

-</=

nC11

2.0

0.5

>nC

11-<

/=nC

12

D-8

6 D

isti

llati

on D

ata:

vol %

D

isti

lled

off:

degF

degC

~~

~C

#

IBP

100

38nC

55%

122

5010

%13

356

20%

152

67nC

630

%17

077

40%

187

8650

%21

199

nC7

60%

236

113

70%

260

127

nC8

80%

283

139

90%

316

158

~nC

995

%34

017

1~

nC10

EP(9

7.5%

)35

918

2

131

TABLE I-7. API Sample 84-01 (Light Parrafinic Distillate)


C4 2.2

C5-C6 39.4 0.9

C7-C8 23.7 13.9

C9-C10 7.6 10.8

C11-C12 0.9 -

C13-C16 - -

C17+ -

132

Tabl

e I-

8. F

ull R

ange

Cat

alyt

ical

ly R

efor

med

Nap

htha

(AP

I 83-

05)

wt

%w

t %

wt

%w

t %

Alip

hati

cAr

omat

icAl

ipha

tic

Arom

atic

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

GC

/MS

ID

C#

(GC

/MS

)C

#(G

C/M

S)

BP

R

ange

BP

Ran

geB

P R

ange

Ben

zene

Tolu

ene

Et.b

enze

neXy

lene

snC

6nC

7nC

9N

apht

hale

neP

yren

e(C

16

)P

NAs

C4s

0.01

>nC

3-<

/=nC

40.

01

C5s

4.0

>nC

4-<

/=nC

53.

9

C6s

7.1

3.0

>nC

5-<

/=nC

66.

73.

02.

0

C7s

1019

.6>

nC6-

</=

nC7

10.3

3.0

19.6

2.16

C8s

4.9

27.3

>nC

7-<

/=nC

85.

119

.64.

4522

.84

C9s

1.1

18.4

>nC

8-<

/=nC

91.

427

.30.

24

C10

s0.

114.

2>

nC9-

</=

nC10

0.11

16.8

0.2

C11

s>

nC10

-</=

nC11

5.7

C12

s>

nC11

-</=

nC12

HC

Typ

e/S

umm

ed27

.272

.527

.572

.4

100

0.00

05~

0.4

100

HC

Typ

e/M

S36

64

HC

Typ

e/D

1319

3763

133

TAB

LE I

-8.

Con

tinue

d

D-8

6 D

ISTI

LLAT

ION

DAT

A:

vol %

D

isti

lled

off:

degF

degC

~~

~C

#

IBP

136

585%

168

76~

~nC

610

%18

283

20%

213

101

nC7

30%

230

110

40%

245

118

50%

259

126

nC8

60%

271

133

70%

286

141

80%

306

152

nC9

90%

326

163

95%

351

177

nC10

EP(9

7.5%

)39

220

0nC

11

Assu

me

that

eac

h bo

iling

ran

ge h

as t

he s

ame

% o

f al

ipha

tics

and

% o

f ar

omat

ics:

(37

vol%

)(6

3 vo

l%)

vol %

vol %

Alip

hati

cAr

omat

icB

P

Ran

geB

P R

ange

BP

Ran

ge

>nC

3-<

/=nC

40

0>

nC4-

</=

nC5

>nC

5-<

/=nC

61.

93.

2>

nC6-

</=

nC7

5.6

9.5

>nC

7-<

/=nC

811

.118

.9>

nC8-

</=

nC9

11.1

18.9

>nC

9-<

/=nC

105.

69.

5>

nC10

-</=

nC11

1.9

3.2

>nC

11-<

/=nC

12

D-1

319

Vol %

Sat

urat

es36

Ole

fins

0.5

Arom

atic

s63

API G

ravi

ty:

44D

ensi

ty:

0.80

45

134

TABLE I-9. API Sample 83-05 (Catalytic Reformed Naphtha)


C4 0.01 -

C5-C6 11.1 3.0

C7-C8 14.9 46.9

C9-C10 1.2 22.6

C11-C12 - -

C13-C16 - -

C17+ -

TABLE I-10. API Sample 81-15 (Catalytic Cracked Clarified Oil)


C4

C5-C6

C7-C8

C9-C10

C11-C12

C13-C16

C17+ (C20+) 8.0 58.3

135

Tabl

e I-

11.

Hyd

rode

sulfu

rized

Ker

osen

e (A

PI 8

1-07

)D

etai

led

hydr

ocar

bon

data

not

ava

ilabl

e, t

hus

the

tabl

e w

ith C

# d

istr

ibut

ion

and

BP

rang

e ca

nnot

be

gene

rate

d

wt

%w

t %

wt

%w

t %

Alip

hati

cAr

omat

icAl

ipha

tic

Arom

atic

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

wt

%w

t %

GC

/MS

ID

C#

(GC

/MS

)C

#(G

C/M

S)

BP

R

ange

BP

Ran

geB

P R

ange

Ben

zene

Tolu

ene

Et.b

enze

neXy

lene

snC

6nC

7nC

9N

apht

hale

neP

yren

e(C

16

)P

NAs

C4s

>nC

3-<

/=nC

4

C5s

>nC

4-<

/=nC

5

C6s

>nC

5-<

/=nC

6

C7s

>nC

6-<

/=nC

70.

1

C8s

>nC

7-<

/=nC

8

C9s

>nC

8-<

/=nC

90.

80.

13

C10

s>

nC9-

</=

nC10

C11

s>

nC10

-</=

nC11

C12

s>

nC11

-</=

nC12

HC

Typ

e/S

umm

ed0.

00.

00.

00.

0

00.

0002

~0.

9

0 HC

Typ

e/M

S71

29

HC

Typ

e/D

1319

7822

136

TAB

LE I

-11.

Con

tinue

d

D-1

319

Vol %

Sat

urat

es77

.3O

lefin

s0.

5Ar

omat

ics

22.2

API G

ravi

ty:

41.8

Den

sity

: 0.

8157

D-8

6 D

ISTI

LLAT

ION

DAT

A:

vol %

D

isti

lled

off:

degF

degC

~~

~C

#

IBP

310

154

nC9

5%38

219

4nC

1110

%39

520

220

%40

920

930

%42

021

5nC

1240

%42

922

150

%43

622

460

%44

322

870

%45

223

3nC

1380

%46

424

090

%48

024

995

%49

325

6nC

14EP

(99.

5%)

533

278

nC15

Assu

me

that

eac

h bo

iling

ran

ge h

as t

he s

ame

% o

f al

ipha

tics

and

% o

f ar

omat

ics:

(78

vol%

)(2

2 vo

l%)

vol %

vol %

Alip

hati

cAr

omat

icB

P

Ran

geB

P R

ange

BP

Ran

ge

>nC

8-<

/=nC

90

0>

nC9-

</=

nC10

>nC

10-<

/=nC

113.

91.

1>

nC11

-</=

nC12

19.5

5.5

>nC

12-<

/=nC

1331

.28.

8>

nC13

-</=

nC14

19.5

5.5

>nC

14-<

/=nC

153.

51

137

TABLE I-12. API Sample 81-07 (Hydrodesulfurized Kerosine)


C4

C5-C6

C7-C8

C9-C10

C11-C12 23.4 6.6

C13-C16 54.2 14.4

C17+ -

tphcwg volume 4

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