Agent Name

Chlorodiphenyl (42% chlorine)

Alternative Name

PCBs (Polychlorinated biphenyls)

CAS Number

53469-21-9

Major Category

Other Classes

Synonyms

PCBs; Polychlorinated biphenyls; Aroclor 1242; Askarel; Eucarel; Pyranol; Dykanol; Clorphen; Asbestol; Diaclor; Nepolin; EEC-18; Kanechlo; UN2315

Category

Halogenated Polyaromatics

Description

Colorless to light-colored, viscous liquid with a mild, hydrocarbon odor; [NIOSH]

Sources/Uses

Exposure to PCBs can occur: 1) from eating contaminated fish, 2) while repairing or maintaining old electrical transformers containing PCBs, and 3) after leakage from old fluorescent lighting fixtures and old appliances such as televisions or refrigerators. [ATSDR ToxFAQs] Also exposed are firefighters of capacitor and transformer fires. [ATSDR Case Studies, PCB Toxicity] Used in elastic polysulfide sealants in prefabricated houses built in Finland between 1959 and 1975, and workers removing sealants may be exposed; [Reference #2]

Comments

This is a family of 209 chemicals, usually mixtures, contaminated with furans and dioxins. They persist in the environment and concentrate upward in the food chain. Primary nonoccupational exposure is from food, especially fish from contaminated water (e.g.. Lake Michigan). PCB's evaporate slowly at room temperature but have increased volatility with small increases in temperature, e.g.. overheated equipment. PCBs can induce chloracne in exposed humans. Abnormal liver function tests may be seen after PCB exposure, but this effect has not been documented in PCB-exposed workers. Serum PCB levels are difficult to interpret, and they are not recommended in the clinical evaluation. "Neonatal PCB syndrome" (low birth weight, hyperpigmentation, eye abnormalities) has been described. PCBs cause fetal loss and low birth weight in experimental animals. [ATSDR Case Studies: PCB Toxicity] A cohort of 7075 capacitor workers, exposed to PCBs in 1946-75 and followed through 1998, has not experienced any excess mortality from cancer or other causes. [PubMed ID: 12661184] "The accepted view is that exposure to PBBs or PCBs leads to hepatic injury only when they are sufficiently contaminated with PCDFs." (PCDFs = polychlorinated dibenzofurans.) [Zimmerman, p. 395] For IARC changes in 2016, see "Polychlorinated biphenyls" and the linked occupational disease.

Restricted

Production of PCBs in the U.S. was banned in 1977.

Reference Link

ATSDR - Index, Polychlorinated Biphenyl (PCB) Case Study

Exposure Assessment
Skin Designation (ACGIH)

Yes

Bioaccumulates

Yes

TLV (ACGIH)

1 mg/m3

PEL (OSHA)

1 mg/m3

MAK

0.003 mg/m3, inhalable fraction

IDLH (NIOSH)

5 mg/m3

Excerpts from Documentation for IDLHs

Other animal data: Chlorodiphenyl (42% Cl) had no discernable effects in cats, rabbits, guinea pigs, rats, and mice after 150 sevenhour exposures to 1.9 mg/m3 over 7 months [Treon et al. 1956]; 17 sevenhour exposures over 24 days at 8.6 mg/m3 also appeared to be noninjurious [Treon et al. 1956]. Slight, reversible, nonspecific liver injury was noted in cats, rabbits, guinea pigs, rats, and mice exposed to 1.5 mg/m3 of chlorodiphenyl (54% Cl) for 7 hours/day for 150 days; 5.4 mg/m3 resulted in more extensive but reversible liver damage [Treon et al. 1956]. Human data: It has been reported that concentrations above 10 mg/m3 were unbearably irritating [Elkins 1959]. Several deaths due to atrophy of the liver have occurred among workers chronically exposed to the fumes of chlorodiphenyls and chloronaphthalenes [von Wedel et al. 1943].

Vapor Pressure

0.001 mm Hg

Explanatory Notes

Flash point = 176-180 deg C;

Half Life

Serum: 1-3 years; [TDR, p. 1035]

Reference Link

Quantitative risk assessment in relation to occupa...[Scand J Work Environ Health. 2005] - PubMed Result

Flammability (NFPA)

1: Must be preheated

Adverse Effects
Hepatotoxin

Hepatotoxin, Secondary

Reproductive Toxin

Yes

Dermatotoxin

Chloracne

IARC Carcinogen

Known Carcinogen

NTP Carcinogen

Anticipated Human Carcinogen

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

Search TOXNET

Chemical Information

Search ChemIDplus

Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure:

Activities

Activities with risk of exposure: