Biphenyl By Ashley Register

Overview Structure, Chemical & Physical Properties Uses and Applications Production History Mode of Entry Chemical Reactivity and Speciation Toxicity to Aquatic Life Biochemical Metabolism Bibliography

Properties 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 Kow indicates highly lipid soluble (confirmed by low water solubility) and has potential for sorption into particulate matter Henry’s law constant indicates chemical could undergo volitalization. Estimated volatilization t1/2 of 4.3 hours

Hazard Classification Classifed as: EPA: Class D carcinogen (not involved in human carcinogenesis) Non-teratogenic EU: Irritant (Xi) Dangerous for the environment (N)

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

Production 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) Tested under section 4 of TSCA

Mode 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 T 1/2 in water is 20 days As mentioned earlier, the Henry constant indicates potential volatilazation

Chemical 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.

Toxicity 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 HIGHLY toxic to aquatic life

Toxicity 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 Values greater than 100 mg/L indicate low chronic toxicity Daphnids are most sensitive species

Toxic 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 My sources have lots of info on the interaction with rats and rabbits if you need more information. As mentioned before, adsorption into the soil and degredation are expected to drastically reduce the bioavailability of biphenyl. Therefore, it is of minor importance to aquatic organisms.

Mode of Entry Biphenyl enters an organism through: Diet (accumulates in plants) Since it is lipid soluble, tends to partition into adipocytes Since biphenyl has a higher probability of entering the atmosphere and being air born than it does of becoming part of the water, bioaccumulation and biomagnification is of minor importance (CICAD) Also, biphenyl is rapidly metabolized by bacterium and most species, so the effect is minimal

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 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.

Biochemical 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 Bioconcentration factor is the concentration of a particular chemical in a tissue per concentration of chemical in water (reported as L/kg). This physical property characterizes the accumulation of pollutants through chemical partitioning from the aqueous phase into an organic phase, such as the gill of a fish. Moderate Potential 1000>BCF>250

Defense Mechanisms Phase I and II metabolism Defense mechanisms are not well developed for Biphenyl due to: Low concentrations being present in water and sediment Since biphenyl tends to volatilize, it rarely interacts with the aquatic environment. When it does, bacterium tend to metabolize biphenyl before it impacts higher organisms. Therefore, comprehensive defense is unnecessary. Also, when biphenyl is encountered, it is rapidly metabolized and excreted.

Conclusion Biphenyl has a high acute toxicity but low chronic toxicity Tends to volatilize Low affinity for water Virtually immobile in sediment Quickly metabolized Acute toxicity because it is usually not something they are exposed to and when they are, it is typically in small amounts.

References 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

References OSHA Hazardous Substances Data Bank (HSDB) 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