BiphenylBiphenyl

By Ashley RegisterBy Ashley Register

OverviewOverview

• Structure, Chemical & Physical Properties

• Uses and Applications• Production History• Mode of Entry• Chemical Reactivity and Speciation• Toxicity to Aquatic Life• Biochemical Metabolism• Bibliography

• Structure, Chemical & Physical Properties

• Uses and Applications• Production History• Mode of Entry• Chemical Reactivity and Speciation• Toxicity to Aquatic Life• Biochemical Metabolism• Bibliography

PropertiesProperties

• 1,1’-biphenyl, diphenyl, phenyl benzene

• Chemical and Physical Properties:– Kow: 4.09– Water Solubility: 7.1 mg/L at 25oC– Henry’s Law Constant: 3E-4 atm

m3/mol

• 1,1’-biphenyl, diphenyl, phenyl benzene

• Chemical and Physical Properties:– Kow: 4.09– Water Solubility: 7.1 mg/L at 25oC– Henry’s Law Constant: 3E-4 atm

m3/mol

Hazard ClassificationHazard Classification

• Classifed as:• EPA:

– Class D carcinogen (not involved in human carcinogenesis)

– Non-teratogenic• EU:

– Irritant (Xi)– Dangerous for the environment (N)

• Classifed as:• EPA:

– Class D carcinogen (not involved in human carcinogenesis)

– Non-teratogenic• EU:

– Irritant (Xi)– Dangerous for the environment (N)

Uses and ApplicationsUses and Applications

• Dye Carrier for Textile dying• Intermediate for PCB’s and PBB’s• Fungicide for citrus fruits• Major component of Heat Transfer

Fluids

• Dye Carrier for Textile dying• Intermediate for PCB’s and PBB’s• Fungicide for citrus fruits• Major component of Heat Transfer

Fluids

Production HistoryProduction History

• Designated for testing in 1982 because 700 million lbs/yr were being produced (Rand)

• US Producers as of 1994:– Chevron Corporation (Baytown, TX)

– Koch Chemical Company (Corpus Christi, TX)

– Monsanto Chemical Company (Anniston, AL)

– Sybron Chemicals Company (Wellford, SC)

• Designated for testing in 1982 because 700 million lbs/yr were being produced (Rand)

• US Producers as of 1994:– Chevron Corporation (Baytown, TX)

– Koch Chemical Company (Corpus Christi, TX)

– Monsanto Chemical Company (Anniston, AL)

– Sybron Chemicals Company (Wellford, SC)

Mode of Entry into Aquatic EnvironmentMode of Entry into Aquatic Environment• Wastewater effluents

– From textile mills that use it as a dye carrier

– From industrial processes

• Leaking heat exchangers• Volatilization and sorption are

important

• Wastewater effluents – From textile mills that use it as a dye

carrier– From industrial processes

• Leaking heat exchangers• Volatilization and sorption are

important

Chemical Reactivity and SpeciationChemical Reactivity and Speciation• Biphenyl tends to partition into the

sediment– Soil sorption coefficients:

• mean value of 4230• Indicates that biphenyl will be practically

immobile in sediment

– But even this effect is minimal, since the majority of biphenyl is volatilized.

• Biphenyl tends to partition into the sediment– Soil sorption coefficients:

• mean value of 4230• Indicates that biphenyl will be practically

immobile in sediment

– But even this effect is minimal, since the majority of biphenyl is volatilized.

Toxicity to Aquatic LifeToxicity to Aquatic Life

• Acute toxicity:– Values as low as 0.36 mg/L

(daphnids) and 1.3 mg/L (rainbow trout).

– LC50 (96h):• Bluegill (L. macrochirus) - 4.7 mg/L• Sheepshead minnow - 4.6 mg/L• Fathead minnow - 6 mg/L

• Acute toxicity:– Values as low as 0.36 mg/L

(daphnids) and 1.3 mg/L (rainbow trout).

– LC50 (96h):• Bluegill (L. macrochirus) - 4.7 mg/L• Sheepshead minnow - 4.6 mg/L• Fathead minnow - 6 mg/L

Toxicity to Aquatic LifeToxicity to Aquatic Life

• Chronic Toxicity:– Done in daphnids and rainbow trout– Daphnids: 275 mg/L

• NOEC: 0.17mg/L

– Trout: 230 mg/L– Indicative of Low Chronic Toxicity– Studies with bacteria indicate no

mutagenic potential

• Chronic Toxicity:– Done in daphnids and rainbow trout– Daphnids: 275 mg/L

• NOEC: 0.17mg/L

– Trout: 230 mg/L– Indicative of Low Chronic Toxicity– Studies with bacteria indicate no

mutagenic potential

Toxic Effects NotedToxic Effects Noted

• In the aquatic environment:– Inhibition of growth

• Noted only in algae (Chlorella)• Slight inhibition at 1 mg/L• Complete inhibition at 10 mg/L

– Inhibition of food intake• Observed in Mytilus edulis• EC50 observed after 40 min of 0.3 mg/L

• Molecular mode of Toxicity:– unknown

• In the aquatic environment:– Inhibition of growth

• Noted only in algae (Chlorella)• Slight inhibition at 1 mg/L• Complete inhibition at 10 mg/L

– Inhibition of food intake• Observed in Mytilus edulis• EC50 observed after 40 min of 0.3 mg/L

• Molecular mode of Toxicity:– unknown

Mode of EntryMode of Entry

• Biphenyl enters an organism through:– Diet (accumulates in plants)– Since it is lipid soluble, tends to

partition into adipocytes

• Biphenyl enters an organism through:– Diet (accumulates in plants)– Since it is lipid soluble, tends to

partition into adipocytes

Biochemical MetabolismBiochemical Metabolism

• Soil:– Biodegredation – S. cerevisiae, Streptomyces, Achromobacter,

Pseudomonas putida, Oscillatoria, gram negative bacteria.

– Oxidize via CytP450 to 2,3 dihydroxybiphenyl– Fungi metabolize biphenyl to 4-hydroxy- or 2-

hydroxy- biphenyl and 4,4’-dihydroxybiphenyl

• Biochemical Metabolism

• Soil:– Biodegredation – S. cerevisiae, Streptomyces, Achromobacter,

Pseudomonas putida, Oscillatoria, gram negative bacteria.

– Oxidize via CytP450 to 2,3 dihydroxybiphenyl– Fungi metabolize biphenyl to 4-hydroxy- or 2-

hydroxy- biphenyl and 4,4’-dihydroxybiphenyl

• Biochemical Metabolism

Biochemical MetabolismBiochemical Metabolism• Water:

– Microbial degradation• Aromatic hydroxylation to 2-, 3-, and 4-

dihydroxybiphenyl• Activated sludge (74% in 14d)• Anaerobic digester (100% in 7d)• Aerated Lagoon (100% in 8h)• Retention Pond (100% in 96h)• Domestic Wastewater (79% in 5d)• Industrial Wastewater (87% in 24h)

– Photolysis• Irradiation with 250 nm light underwent 50%

degradation in 40 hours.

• Water:– Microbial degradation

• Aromatic hydroxylation to 2-, 3-, and 4- dihydroxybiphenyl

• Activated sludge (74% in 14d)• Anaerobic digester (100% in 7d)• Aerated Lagoon (100% in 8h)• Retention Pond (100% in 96h)• Domestic Wastewater (79% in 5d)• Industrial Wastewater (87% in 24h)

– Photolysis• Irradiation with 250 nm light underwent 50%

degradation in 40 hours.

Biochemical MetabolismBiochemical Metabolism

• Biota:– Bioconcentration Factors:

• Rainbow Trout - 436 L/kg• Algae - 540 L/kg• Orfe - 282 L/kg

– Suggests a moderate potential for accumulation in aquatic organisms

– Kow indicates an affinity for lipids

• Biota:– Bioconcentration Factors:

• Rainbow Trout - 436 L/kg• Algae - 540 L/kg• Orfe - 282 L/kg

– Suggests a moderate potential for accumulation in aquatic organisms

– Kow indicates an affinity for lipids

Defense MechanismsDefense Mechanisms

• Phase I and II metabolism• Defense mechanisms are not well

developed for Biphenyl due to:– Low concentrations being present in

water and sediment

• Phase I and II metabolism• Defense mechanisms are not well

developed for Biphenyl due to:– Low concentrations being present in

water and sediment

ConclusionConclusion

• Biphenyl has a high acute toxicity but low chronic toxicity

• Tends to volatilize• Low affinity for water• Virtually immobile in sediment• Quickly metabolized

• Biphenyl has a high acute toxicity but low chronic toxicity

• Tends to volatilize• Low affinity for water• Virtually immobile in sediment• Quickly metabolized

ReferencesReferences

• Rand, G.M. Fundamentals of Aquatic Toxicology: Effects, Environmental Fate, and Risk Assessment. 2nd Edition. CRC Press, New York, NY, 1995.

• Concise International Chemical Assessment Document (CICAD)– www.inchem.org/documents/cicads/cicads/cicad06.htm

• International Program on Chemical Safety (IPCS)– www.inchem.org

• National Pollution Inventory, Australian Government.– www. Npi.gov.au/database/substance-info/profiles/14.html

• Rand, G.M. Fundamentals of Aquatic Toxicology: Effects, Environmental Fate, and Risk Assessment. 2nd Edition. CRC Press, New York, NY, 1995.

• Concise International Chemical Assessment Document (CICAD)– www.inchem.org/documents/cicads/cicads/cicad06.htm

• International Program on Chemical Safety (IPCS)– www.inchem.org

• National Pollution Inventory, Australian Government.– www. Npi.gov.au/database/substance-info/profiles/14.html

ReferencesReferences

• OSHA– www.osha.gov

• Hazardous Substances Data Bank (HSDB)– http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB

• US Environmental Protection Agency (EPA)– www.epa.gov

• TSCA Compliance Guide– www.tsca.info

• OSHA– www.osha.gov

• Hazardous Substances Data Bank (HSDB)– http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB

• US Environmental Protection Agency (EPA)– www.epa.gov

• TSCA Compliance Guide– www.tsca.info