Cas No. 1336-36-3

Polychlorinated Biphenyls

(PCBs, Aroclors)

Cas No. 1336-36-3

Potential exposure

Polychlorinated biphenyls (PCBs) are a family of man-made chemicals that

contain 209 individual compounds (referred to as congeners). Some commercial

PCB mixtures are referred to by their industrial trade name, Aroclor. Due to their

thermal stability, inflammability, and dielectric capability, PCBs were used in

electrical capacitors and transformers. Although PCBs are no longer

manufactured or used in this country, they have entered the environment from

accidental spills, leaks from transformers or capacitors, or mismanaged electrical

equipment wastes. Due to their chemical properties, PCBs are persistent in the

environment; they do not readily break down and are bioconcentrated in the food

chain. Humans might be exposed to PCBs in contaminated air, water, soils or

food, such as fish.

Physical and chemical properties

Property

Value

For Aroclor 1260

Molecular weight

375.7 g/mol

Water solubility

0.0027 mg/L

4.05 10-5 mm Hg at 25 oC

Vapor pressure

Koc

no data available

log Kow

6.8

4.6 10-3 atm-m3/mol at 25 oC

Henry's Law Constant

Toxicity

Exposure to PCBs has caused dermatologic effects, in particular, chloracne.

Cases of severe chloracne were reported in by workers exposed for 2 to 4 years

in which PCB air levels were between 5.2 and 6.8 mg/m3 (ATSDR 1991). Other

effects might include dry sore throat, skin rash, gastrointestinal disturbances, eye

irritation, and headache with inhalation exposures below 0.15 mg/m3 PCB. There

is some evidence of liver cancer in humans when exposed to PCBs via the

inhalation, gastrointestinal, or dermal pathways. Confounding factors in these

studies include the simultaneous exposure to polychlorinated dibenzofurans.

Higher blood PCB levels are associated with elevated serum triglyceride and/or

cholesterol levels, as well as elevated blood pressure. Some of these effects are

D63

Appendix D Toxicological Profiles