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MINUTES OF THE MEETING NFPA

TECHNICAL COMMITTEE on HAZARDOUS MATERIALS PROTECTIVE CLOTHING AND EQUIPMENT

Dallas, TX October 1-2, 2014

Attendance: Principal Members/Staff: Christina Baxter US Department of Defense, Chair Pat Gleason Safety Equipment Institute (SEI), Secretary David Trebisacci NFPA Staff Liaison Jason Allen Intertek Brian Clifford Federal Bureau of Investigation Richard Daly St. Charles Fire Department Russell Greene Battelle Memorial Institute William Haskell NIOSH NPPTL Michael Kienzle W.L. Gore & Associates, Inc. Susan Lovasic The DuPont Company Karen Lehtonen Lion Apparel Inc. Philip Mann Kappler, Inc. Ulf Nystrom Ansell Protective Solutions AB Paul Rogers Fire Department City of New York Jeff Stull International Personnel Protection, Inc. John Wisner United Fire Company No. 3 James Zeigler JP Zeigler, LLC Voting Alternate: Douglas Bledsoe US Federal Bureau of Investigation Dale Beggs Texas Instruments Beth Lancaster US Department of Defense Amanda Newsom UL LLC Bryan Ormand NC State University Kristin Williamson The DuPont Company Absent Principal Members with no Alternate present Ted Buck Orr Safety Todd Haines Dallas/Fort Worth International Airport Bruce Kelly Fairfield County Hazardous Incident John North Alexandria Fire Department Michael O’Loughlin Onguard Industries Lou Ott International Safety Equipment Association Kenneth Pever Guardian Manufacturing Company Samuel Pitts USMC Systems Command Robert Shelton City of Cincinnati Fire Department Richard Shoaf St. Charles Fire Department Steven Torment International Association of Fire Fighters Michael Ziskin Field Safety Corporation

Guests A Shawn Deaton NC State University Elaina Franks Kappler, Inc. William Gabler NC State University Ryan Hirschey Saint Gobain Emiel Den Hartog NC State University Chris Mekeel NCSU/TPACC J.D. Fort Worth FD 1. Call to order. The meeting was called to order at 9:10 a.m. on October 1, 2014 by Technical Committee (TC) Chair, Dr. Christina Baxter. 2. Welcome & Introductions. Dr. Baxter welcomed everyone. Members and guests introduced themselves and their affiliation. Dr. Baxter thanked everyone for their participation in this meeting to address the Testing Task Group input for the draft NFPA 1991. She outlined the plan for this meeting. 3. Minutes Approval. The minutes from the NFPA 1991 First Draft meeting held on February 18-19, 2014 in Raleigh were approved by the TC. 4. NFPA Staff Report and Discussion of Document Revision Process. The NFPA Staff Liaison, Mr. Dave Trebisacci, provided general information on NFPA procedures and timelines in an opening presentation. He addressed NFPA antitrust and patent policies to be adhered to as well as composition and balance of the TC. Mr. Trebisacci stated that the Hazmat TC is in balance. He noted that NFPA 1991 is in the Fall 2015 cycle and the Public Comment period will close November 14, 2014 at 5:00 pm. The Second Draft meeting for NFPA 1991 is planned for January 20-23, 2015 in San Diego. NFPA 1991 is expected to be on the NFPA Standards Council agenda for approval in November 2015. NFPA 1992 and NFPA 1994 Additionally, Mr. Trebisacci reminded the TC that NFPA 1992 and NFPA 1994 are in the Fall 2016 revision cycle. The Public Input stage of the revision process will be open until January 5, 2015, with the First Draft meeting scheduled for January 2015 as noted above. The NFPA standard revision/development process can be found at www.NFPA.org/1991. 5. NFPA 1991 Revision. The attached presentation, NFPA 1991 Task Group Report (see Attachment 1), was provided to share test data and summarize the status of the work being conducted by the NFPA 1991 Task Group. Flame Resistance Following discussion on the Flame Resistance Test, it was decided that a Public Comment would be submitted to clarify the determination for melting for the baseline and flash fire to “melting AND dripping”, to incorporate the ASTM F1358 test method with updated ASTM D6413 equipment and designate a 3 second baseline endpoint and a 12 second flash fire endpoint, and to incorporate a supplemental break open test based on MIL 83480B.

http://www.nfpa.org/1991

Alternate Flash Fire Test Following discussion on alternatives to the overall ensemble flash fire test, it was decided that the Task Group would take the following actions to assist in determining an appropriate test: Provide specific data on measuring heat flux in the current flash fire test and use that information to determine the appropriate time for the manikin tests. Public Comments will also be submitted to allow the use of a full garment configuration for testing on the manikin, and to allow testing of a facsimile garment on the manikin based on use of the ASTM F1930 pattern. MIST vs. SF6 The Task Group reviewed the two tests and the problems associated with the SF6 method. It was noted that the quality issues with PAD’s are close to resolution, and the new supplier information will be provided to the Testing TG. It was noted that there must be supportive data presented for changing the test method from SF6 to a modified MIST. The Testing TG was assigned the task to provide results of verification testing at Intertek and NC State. The Task Group volunteered to validate that the laboratories have the ability to maintain increased concentration of 150 in their chamber (4 subjects / 2 hrs + - 10). This information will be shared with the TC. Public comments will be submitted to increase the concentration to 150 and setting the endpoints. Visor Physical Properties Jason Allen reviewed results on physical property testing conducted on visors using the ANSI Z87.1 standard physical challenges. Additional comparative testing will be performed on samples following removal from a -25 0C environment with an alternative probe using unacceptable material. Public Comments will be submitted based on the results. Visor Field of View A proposed Visor Field of View Test protocol was reviewed. As there may be concerns with variables being created by the type of SCBA being used, those Task Group members attending the upcoming IAB meeting in Arlington, VA will perform testing at off times during the IAB meeting to gain user input into potential endpoints and test design. A public comment will be submitted following the additional testing. Encapsulating vs. Non-Encapsulating The Task Group was charged with the task of identifying a potential path forward following a review of the entire document to address the testing of a respirator face piece in those areas where visor testing has been designated. The Scope statement in 1.1.7 will need to be revised. A modified inflation test must also be proposed. With potential issues regarding limited barrier testing, the TG will also need to propose a potential warning label on the garment stating that the respiratory protection has not been tested against the chemical battery. It was noted that it may be appropriate to create an Annex item stating that the pressure test does not incorporate the face piece (seal). A teleconference of the TG will be scheduled to address these issues. Cumulative vs. Breakthrough Permeation Kristin Williamson reviewed research conducted per the attached presentation Comparison - Cumulative Mass Permeation versus Normalized Breakthrough Time (see Attachment 2).

Following significant discussion, several assignments were made as the Task Group moves forward. Public comments will be submitted to provide greater detail regarding performance requirements and test methods to include testing at 15 minute intervals over a 60 minute period to accommodate for materials which may have “spikes” in breakthrough, and end points will need to be justified. Russ Greene, Chris McKeel and Jeff Stull were asked to provide information related to this issue, liquefied gas and the analytical methodologies required, respectively. Multi-Layer Visor Systems Public Comments will be submitted to add clarification language for multi-layer visor systems. Footwear and Glove Flexing Discussion on the lack of benefit of this test resulted in a plan for Public Comments to be submitted to remove requirements for the flexing of footwear and glove samples. Tech Data Packages It was noted that there is a lack of consistency in Technical Data Packages. Beth Lancaster requested all manufacturers to provide examples of Tech Data Packages to her as soon as possible. Public Comments will be submitted to develop an outline/template of required Technical Data Package elements and their organization. 6. 1992 Path Forward

Consider developing a survey to ask operators what protection they think a 1992 suit provides

Chemical challenge list within 1992 is lacking. Develop a proposed chemical list based upon viscosity, surface tension and chemical degradation methodologies

Review the Flash Fire option as nobody has ever certified to this due to the post flame liquid challenge

Perform a review of the standard and ensure that all test method issues that were addressed in 1991 are incorporated within 1992, where applicable

7. 1994 Path Forward

Further evaluate Chlorine and Acrolein test methods and potential pitfalls as seen by NCSU

Sock and glove testing needs to be re-evaluated

Durability requirements - can/should an optional ruggedized requirement be added 8. Next Meeting. The next meeting of the TC will be held January 20-23, 2015 in San Diego. This will be the Second Draft meeting for NFPA 1991, and the First Draft meeting for NFPA 1992 and NFPA 1994. 9. Adjournment. There being no further business before the TC, the meeting adjourned at 2:00 p.m. on October 2, 2014. Respectfully submitted by: Patricia Gleason Secretary NFPA Technical Committee on Hazardous Materials Protective Clothing and Equipment

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1

NFPA 1991Task Group Report

Technical Committee on HazMat Protective Clothing and EquipmentMeeting – Dallas, 1‐2 October 2014

NFPA 1991 Task GroupJason AllenJeff Stull

1

Primary Working Topics

• Flame resistance test modifications – Stull

• Visor physical properties – Allen

• Visor field of view – Allen

• Alternative flash fire test – Mann

• MIST vs SF6 – Ormond

2

End User Survey Priorities from 2013

238

245

311

325

380

427

450

569

613

630

0 100 200 300 400 500 600 700

Overall durability (10/90)

Flame/heat resistance (9/89)

Wearing comfort (17/115)

Speaking communications (15/107)

Liquid penetration (33/110)

General mobility (19/118)

Field of vision (39/132)

Fine hand function (34/178)

Clarity of vision (66/167)

Physical hazard resistance (60/197)

Number of points based on scaled system (5 pts – 1st priority; 1 pt – 5th priority)Information after priority area (# of first priority responses/# of total responses) 3

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Flame Resistance Test

• Issues:– Compliance may be affected by test practice and interpretations (e.g., determination of melting)

– Test method undergoing change– Baseline criteria may be too severe

• Prior Action Items:– Examine historical compliance data– Establish practice for indicating melting – Review changes to related ASTM D6413 test method

– Revisit existing criteria for baseline tests

4


• Task Group Approach:

– Investigated likely hazards for each response level –incidental flame or heat exposure versus flash fire exposure

• Most likely flame exposures from incidental contact with small flames

– Determined applicability of current test methods

• Majority of tests focus on extreme exposures

– Applied scenario‐based testing on products (simulations)

• Testing:– 10 different materials evaluated

• 2 glove, 2 footwear, and 6 garment materials

– Four industry tests applied in modified format:• ASTM F1358 (folded edge)

• ASTM D6413 (cut edge)

• ASTM D1230, modified, surface impingement

• MIL 83480B, break open

– Modifications involved 3 and 6 second flame exposures in lieu of longer or shorter flame contact


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• Test Materials:


Type Material Description Designation

Glove 17‐18 mil Butyl rubber (unsupported) Glove A

18 mil Neoprene (unsupported) Glove B

Footwear Standard PVC Footwear C

FR PVC alloy Footwear D

Garment Plastic laminate (film/fabric) Garment E

Plastic laminate (film/fabric/film) Garment F

Aluminized fabric over plastic laminate Garment G

Film/textile laminate Garment H

FR file/textile laminate Garment I

Elastomer coated film laminate Garment J

• Small Scale Test Methods:


ASTM F1358 Folded Edge

ASTM D6413 Cut Edge

ASTM D1230 Impingement

MIL 83480B Break Open


Mat’lFlame Simul. ASTM F1358 ASTM D6413 D1230 MIL 83480B

Ignite Drip Ignite Drip Ignite Drip Ignite Hole Drip

A No No Yes Yes Yes Yes No No No

B No No Yes Yes Yes No No No No

C No No Yes No Yes No No No No

D No No Yes No Yes No No No No

E Yes Yes Yes Yes Yes No No Yes Yes

F Yes Yes Yes Yes Yes Yes No Yes No

G No No No No Yes No No No No

H Yes Yes Yes Yes Yes Yes No No No

I ‐‐‐ ‐‐‐ No No No No No No No

J No No Yes No Yes No No No No

Test Results: 3‐Second Exposures

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Mat’lFlame Simul. ASTM F1358 ASTM D6413 D1230 MIL 83480B

Ignite Drip Ignite Drip Ignite Drip Ignite Hole Drip

A Yes Yes Yes Yes Yes Yes No No No

B No No Yes Yes Yes Unk. No No No

C No No Yes No Yes No No No No

D No No Yes No Yes No No No No

E Yes Yes Yes Yes No No Yes Yes Yes

F Yes Yes Yes Yes Yes No No Yes Unk.

G No No No No No No No No No

H Yes Yes Yes Yes Yes No Yes No No

I ‐‐‐ ‐‐‐ Yes No Yes No No No No

J Yes No Yes No Yes No No No No

Test Results: 6‐Second Exposures

• Flame Exposure Simulation:– UL94 adapted for holding glove, footwear, or garment samples for simulating short‐term contact with pilot flame

• 3 and 6 second exposures

• Observation of ignition, if occurred

• Observations of item response to flame exposure

– Deformation, distortion or hole formation

– Dripping

– Burning until consumption


Glove suspended in chamber over burner


• Observations:– 6 second test exposures almost always more severe than 3 second test exposures

– ASTM F1358 and ASTM D6413 similarly rate materials for ignition and dripping with some exceptions

• Multiple layer materials

• Longer after flame times usually for folded edge

– Flame simulation less severe than either ASTM F1358 or ASTM D6413 tests

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• Radiant Heat Exposure Simulation:– Procedure based on NFPA 1981, Lens Radiant Heat Test (Section 8.28)

• Fuel‐fed radiant panel

• Heat flux of 15 kW/m2

• Distance of 7 in.

• Total exposure of 5 min (reduced to 6, 10 seconds for simulation)

– Alternative techniques used to hold clothing samples


Radiant panel and test apparatus used to expose samples


Item 6 sec Ignition 6 sec Melting 10 sec Melting Observations

Glove A No No No

Glove B No No No

Footwear C No No No

Footwear D No No No

Garment E No Yes Yes Shrinkage; pinholes*

Garment F No No Yes

Garment G No No No

Garment H No No No Slight shrinkage*

Garment I No No No

Garment J No No No

* Observed for both 6 and 10 second exposures

Test Results: Radiant Heat Exposure Simulation


Material6s Flame Sim. 3‐s F1358 3‐s D6413 10‐s RS 3‐s MS

Ignite Drip Ignite Drip Ignite Drip Melt Hole

Glove A Yes Yes Yes Yes Yes Yes No No

Glove B No No Yes Yes Yes No No No

Footwear C No No Yes No Yes No No No

Footwear D No No Yes No Yes No No No

Garment E Yes Yes Yes Yes Yes No Yes Yes

Garment F Yes Yes Yes Yes Yes Yes Yes Yes

Garment G No No No No Yes No No No

Garment H Yes Yes Yes Yes Yes Yes No No

Garment I ‐‐‐ ‐‐‐ No No No No No No

Garment J Yes No Yes No Yes No No No

Analysis: Small Scale Methods versus Simulations

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• Further Test Methods Issues:– Update equipment specifications, apply procedures for small samples

– Determination of melting: Use “melting or and dripping”

• Suggested Flame Resistance Testing Approach:– Specify ASTM F1358 with updated ASTM D6413 equipment

– Differentiate baseline versus flash fire tests• 3 versus 12 second exposure time• Break open test supplements baseline flame resistance test• Measurement of burn distance for flash fire criteria only• Less rigorous melt definition for baseline criteria

Visor Physical Properties

• Issue:– Rigid visor materials cannot be tested for physical properties without breaking apparatus

• Prior Action Items:– Establish basis for determining visor material as rigid

– Identify and validate alternative methods for evaluating visor physical properties

17


• Current Test Methods:

Burst Strength Puncture Propagation Tear

Cold Temperature Bend

18

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• Initial Possible Solutions:– Characterize visor material rigidity by selected method and establish threshold level

• Bending length (ASTM D1388)

– Apply other industry methods to rigid visors

• Falling dart (ASTM D1709)

• Drop ball or high mass impact tests (ANSI Z87.1)

19


• Task Group Direction:

– Apply other ANSI Z87.1 methods to all visors

• Drop ball, Puncture (penetration), High Mass

– Build special fixture to hold visors for tests

This image cannot currently be displayed.

20


• Test Fixture

• ANSI Z87.1 Physical Challenges

Drop Ball Puncture Probe High Mass

21

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• Summary of Test Results:

Challenge Visor A Visor B* Visor C Visor D Visor E

Visor Type Rigid formed visor

Non‐NFPAvisor

Flexible 1991 Visor

Flexible 1991 Visor

Flexible 1991 Visor

Drop Ball No visible change

No visible change

No visible change

No visible change

No visible change

Puncture Small dent; surface damage

Full puncture Full puncture Full puncture Full puncture

High Mass Visible indent Elongation; no hole; significant movement**

Small dent, 1‐inch movementafter impact

Small dent Small dent

* Non‐NFPA 1991 visor; ** ½ inch hole formed in one specimen with no movement

22


• Observations:

– Additional work is needed to get more significant sample size, but appears repeatable

– All current NFPA 1991 products tested passed

– Need to define allowable movement upon impact to improve consistency. i.e. less than 6mm or ¼” movement

• Cold temperature impact needed?

23


• Due to the lack of visible damage, the drop ball test was removed and testing will be performed for puncture resistance and high mass impact only.

• Puncture testing for this round will be performed using a probe profile like what is utilized in current PPT testing and at a similar kinetic energy.

• All testing will be performed on a sample upon removal from a ‐25C environment

• Need some additional materials from some mfrs if available

24

Testing Round 2:

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Visor Field of View

• Issues:

– Highly ranked priority identified in 2013 survey

– Not addressed in NFPA 1991

25

Visor Field of View

• Proposed Method:

1. Test Subject stands upright looking forward with the SCBA on but without the suit against the wall:

26

Visor Field of View


27

2. Tape Measure is mounted to the floor at the intersection of the Coronal and Sagittal Planes

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Visor Field of View


28

3. With back straight and the SCBA against the wall the test subject bends at neck only and looks down determining the closest point on the measuring tape they can see

Visor Field of View


29

4. Suit is donned and test subject stands in the same location with SCBA against the wall

Visor Field of View


30

5. With back straight and SCBA against the wall the test subject bends at neck only and looks down determining the closest point on the measuring tape they can see

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Visor Field of View

• Establishment of Proposed:

– Difference between Pre‐suit point observed on the floor and post suit point observed shall be less than X mm

– Shall be able to see X distance from the intersection point of the Coronal and Sagittal planes

31

Visor Field of View 2.0

• User Suggestions:

– Consider using NFPA Placards vs. Distance seen

– FOV Upwards equally important. Ex: Looking upwards into back of tractor trailer

32


‐Attempted to correlate NFPA 704 placard/letter height to SnellenEyechart currently used in Form, Fit and Function

‐Settled on 1” letter height = 50’ Placard size

33

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1. Test Subject without the suit stands upright looking forward with the SCBA on but against the wall.

2. Test Subject dons suit. NFPA 704‐based placards with randomized numbers are placed at the specified locations measured from between the users eyes. Placard shall be perpendicular to the users viewing angle.

3. Test Subject reads each number clockwise from the blue diamond. Proposed Pass/fail at each location‐ 3 out 3 letters successfully identified

34

Visor Field of View REV2

‐Additional Work Needed to determine Pass/Fail:

‐Propose working with IAB users at upcoming meeting in October to suggest values

35

Location Distance (m) Horizontal Angle Vertical Angle

Downward 2.0 0° TBD

Temporal 6.0A TBD 0°

Upwards 2.0 0° TBD

Overall Ensemble Flash Testvs.

Thermal ManikinOverall Ensemble Flash Test

• PRO’s– More labs can run test– Less expense– Ability to test garment post

flash– Tests the full system

• CON’s– Limited environmental test

window– Repeatability issues– Does not address user

survivability via skin burn

Thermal Manikin

• PRO’s– Measures heat flux for skin

burn evaluation

– Good repeatability

• CON’s– Must cut hole in garment to

route sensor wiring

– Not testing actual system with components

– Redundant testing

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Proposal• Instrument the manikin in the current ensemble flash test

• 15 copper calorimeters located similar to MIST locations, address contact and non‐contact

• Pass thru device for routing cables out of garment, plug hole for post flash pressure test

• Discussions with UL and ITS indicate capability to test and evaluate data

• Kappler will fund the construction of test instrumented test manikin

Flash Fire Performance Test

• Issues:– Difficulty in achieving consistent test conditions; test repeatability

– Variation in test practice between laboratories

• Prior Action Items:– Compare lab test practices (ITS/UL) – Investigate test method changes (chamber cover, dummy SCBA, igniter, visual acuity measurement)

– Measure gas concentrations to determine chamber uniformity

– Increase from 1 to 3 replicates

38

Overall Ensemble Inward Leakage• Issues:

– Test is complicated and difficult to run– Corrections are needed to address errors and

differences in lab practice

• Prior Action Items:– Provide corrections to test method for flow rate

tolerance, sampling port configuration, and equation

– Consider MIST as alternative test

Return air

Pump B

Pump A

Sample Bag

Sample Bag

Test ChamberSampling Valves

1

2

3

4

Sampling Locations1 – Middle of back2 – Sternum 3 – Forearm or calf4 – Crotch NOTE – All tubing enters suit at same location to make wearer movement possible; origin of tubes inside suit show sampling location NOT point of suit entry. 39

Comparison - Cumulative Mass Permeation versus Normalized Breakthrough TimeReview for NFPA 1991 Committee (Oct. 1-2, 2014)

Kristin Williamson, Ph.D.DuPont

ASTM F739 Test Cell

Liquid Level

Test ChemicalTo Analyzer

Purpose: Evaluate the conclusion from the recent Battelle

theoretical study…

“Cumulative sampling offers the most reliable and accurate method of sampling.”

… with actual lab testing.

Experimental: Tychem® SL fabric was tested against 5 chemicals

with known permeation breakthrough times (@ 0.1µg/cm2/min) of <80 minutes at Intertek via two protocols using NFPA 1991 method and conditions: Test A: Tested for NBT with 5 minute interval sampling for

60 minutes

Test B: Tested for Cumulative Mass at end of 60 minutes

ChemicalsNFPA 1991 Chemical

Typical Permeation NBT @ 0.1 Test A Test B

Acetone (99%) X <10 X XAcetonitrile (99%) X 68 X XAcetyl Chloride (98%) 37 X XBenzene (99%) <10 X XDimethyl Formamide (N,N‐) (99%) X 78 X X

Study Objectives:1. Determine if sampling at 5 minute intervals is

possible at the laboratory.

2. Determine if cumulative mass reported is statistically different using method A vs. method B for the same chemical.

3. Determine if maximum permeation rate reported is statistically different using method A and method B for the same chemical.

Note: Acetonitrile (99%) & Benzene (99%) Lab had difficulties obtaining the data from the

MiniCams for Acetonitrile and Benzene because the accumulated concentration was above the detection limit. This was true for both the Test A and Test B scenarios. Therefore data for these chemicals was not analyzed for this study.

Conclusions1. Determine if sampling at 5 minute intervals is

possible at the laboratory.Yes.

2. Determine if cumulative mass reported is statistically different using method A vs. method B.

Chemical Test A vs. Test B

Acetone Statistically Significant Difference

Acetyl Chloride Not Statistically Significant Difference

Dimethyl Formamide (N,N-) Not Statistically Significant Difference

Conclusions3. Determine if maximum permeation rate reported is

statistically different using method A and method B.

Chemical Test A vs. Test B

Acetone Statistically Significant Difference

Acetyl Chloride Not Statistically Significant Difference

Dimethyl Formamide (N,N-) Statistically Significant Difference

Results Example: N,N-dimethyl Formamide (99%) - Overall

Dimethyl Formamide (N,N-)

BT (min)@ 0.1

Cumulative Permeation

Mass (µg/cm2)

Maximum Permeation Rate

(µg/cm2/min.)

Test A

Cell 1 10 197.31 34.48Cell 2 10 200.57 33.11Cell 3 10 236.8 36.56Average 10 211.56 34.72

Test B

Cell 1 <60 182.42 3.04Cell 2 <60 162.28 2.70Cell 3 <60 166.81 2.78Average <60 170.5 2.84

0

5

10

15

20

25

30

35

40

0 20 40 60 80

Per

mea

tio

n (

µg/cm

/min)

Time (minute)

Test A

Sample #1

Sample #2

Sample #3

0

0.5

1

1.5

2

2.5

3

3.5

0 20 40 60 80

Per

mea

tio

n (

µg

/cm

/min

)

Time (minute)

Test B

Sample #1

Sample #2

Sample #3

Results Example: N,N-dimethyl Formamide (99%) – Cumulative Permeation While the means seem to

be different, the differences are not significant at 95% CI because the interval bars overlap.

The two sample t-test confirms this with a p-value of 0.100 indicating the difference in the means is not statistically significantly.

Test A and Test B methods do not result in statistically significant different cumulative permeation results.

Test BTest A

275

250

225

200

175

150

TestD

MF

(99%

) - C

umul

ativ

e Pe

rm

Interval Plot of DMF (99%) - Cumulative Perm95% CI for the Mean

Individual standard deviations were used to calculate the intervals.

Two-Sample T-Test and CI: DMF (99%) - Cumulative Perm, Test Two-sample T for DMF (99%) - Cumulative Perm Test N Mean StDev SE Mean Test A 3 211.6 21.9 13 Test B 3 170.5 10.6 6.1 Difference = μ (Test A) - μ (Test B) Estimate for difference: 41.1 95% CI for difference: (-19.4, 101.5) T-Test of difference = 0 (vs ≠): T-Value = 2.92 P-Value = 0.100 DF = 2

Results Example: N,N-dimethyl Formamide (99%) – Maximum Permeation Rate The bars do not overlap;

therefore, the difference in the means is statistically significant at 95% CI.

This is confirmed in the two sample t-test with a p-value of 0.001 indicating the difference in the means is statistically significant.

The actual maximum permeation rate was not accurately reflected in the cumulative permeation method (Test B).

Test BTest A

40

30

20

10

0

Test

DM

F (9

9%) -

Max

. Per

m. R

ate

Interval Plot of DMF (99%) - Max. Perm. Rate95% CI for the Mean

Individual standard deviations were used to calculate the intervals.

Two-Sample T-Test and CI: DMF (99%) - Max. Perm. Rate, Test Two-sample T for DMF (99%) - Max. Perm. Rate Test N Mean StDev SE Mean Test A 3 34.72 1.74 1.0 Test B 3 2.840 0.178 0.10 Difference = μ (Test A) - μ (Test B) Estimate for difference: 31.88 95% CI for difference: (27.54, 36.21) T-Test of difference = 0 (vs ≠): T-Value = 31.62 P-Value = 0.001 DF = 2

Maximum Permeation Rate Examples

Experimental Two Tychem® fabrics were submitted to ICS

Laboratories for ASTM F739 testing with Diethylenetriamine (99%) and Ethylbenzene (99%) as part of another program.

Interesting results were obtained.

Results: Diethylenetriamine (99%) –Tychem® CPF3

Sampling was every 3 minutes

Results: Cumulative Mass for Diethylenetriamine (99%) vs Tychem® CPF3

1.8 ug/cm2 is the 120 minute result

A fabric with an actual breakthrough time and normalized (0.1) breakthrough time of 3 minutes (which would have failed the existing NFPA 1991 requirements) would easily pass the proposed cumulative permeation mass requirement of <6 ug/cm2.

Results: Ethylbenzene (99%) - Tychem® SL

Sampling was every 3 minutes

Results: Cumulative Mass for Ethylbenzene vs Tychem® SL

3.0 ug/cm2 is the 120 minute result

A fabric with an actual breakthrough time of 6 minutes and a normalized (0.1) breakthrough time of 8 minutes (which would have failed the existing NFPA 1991 requirements) would easily pass the proposed cumulative permeation mass requirement of <6 ug/cm2.

Summary This ICS Lab data represents examples of

permeation “spiking” behavior that would have failed the 0.1 µg/cm2/min criteria but would pass the <6.0 µg/cm2 cumulative mass permeation threshold that is proposed in Draft #1 of NFPA 1991-2015.

Conclusions Based on this Testing There is insufficient data to support the theory that “cumulative sampling offers

the most reliable and accurate method of sampling” when compared to a 5 minute interval sampling technique.

Sampling at 5 minute intervals during 60 minute testing Can closely approximate the cumulative permeant mass which was determined after

60 minutes. Can detect spikes of permeation which may then subside for rest of the test period.

This study highlights the deficiency of the proposed cumulative mass permeation method (only sampling at the end) to identify the maximum permeation rate (e.g. spike). Both types of performance responses are important for assessing NFPA 1991 material

performance for chemical permeation

Since end-users are accustomed to assessing suit performance using normalized breakthrough times, why should NFPA 1991 now switch from discrete sampling for breakthrough time to only using cumulative mass? If improved accuracy is needed, then increased sampling frequency of the normalized

breakthrough test method should be required in the new revision of NFPA 1991.

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