Pentachlorophenol

Synonyms

Sodium pentochlorophenate [ATSDR Case Studies # 23] Dowicide; PCP; Penchlorol; Penta; Penta Plus; Pentachloral; Pentacon; Penwar; Priltox; Santobrite; Santophen; Sinituho; Weedone; [EXTOXNET]

Category

Chlorophenols

Description

Colorless to white, crystalline solid with a benzene-like odor; [NIOSH]

Sources/Uses

Used as an industrial wood preservative for power-line poles, cross arms, fence posts, railroad ties, and wharf pilings; no longer used to treat wood products for log homes, outdoor furniture, or playground equipment; registered by EPA as a restricted-use pesticide since 1984; no longer registered for use as a pesticide (termiticide), fungicide, herbicide, molluscicide, disinfectant, or paint anti-fouling agent; it's use as a slimicide in cooling towers is being phased out; non-wood uses account for less than 2% of US consumption; PCP is manufactured at only one facility in the US (Wichita, Kansas). [ATSDR ToxProfiles] Production in the US ended in 1992; [ACGIH]

Comments

PCP causes the uncoupling of oxidative phosphorylation resulting in the release of cellular energy as heat. Technical grade PCP is contaminated with furans, dioxins, and other chlorinated congeners. Liver injury and mild and transient renal dysfunction associated with pentachlorophenol poisoning have been reported. [ATSDR Case Studies #23] In acute poisoning, PCP causes hyperpyrexia, vascular collapse, and acute renal failure. [LaDou, p. 417] PCP has caused chloracne in exposed workers. TLV Basis: Irritation (upper respiratory and eye); Impairment (CNS and cardiovascular); [ACGIH] Cases of aplastic anemia and leukemia were temporally associated with exposure to pentachlorophenol, but causality was not established. [EPA Pesticides] PCP was manufactured in the US from 1937 to 1980. Twenty percent of production workers developed chloracne as a result of high dioxin (TCDD) exposure. [PMID 19786897] See "TCDD." "PCP was classified by the Working Group as carcinogenic to humans (Group 1), based on sufficient evidence that PCP causes non-Hodgkin lymphoma in humans. In all of the available epidemiological studies, exposure to PCP was positively associated with non-Hodgkin lymphoma." [IARC, News Release, 24 October 2016]

In 1987, EPA restricted the use of PCP to certified applicators.

Reference Link #1

Biomedical References

PCP in urine (with hydrolysis) prior to last shift of workweek: Nq ("Biological monitoring should be considered for this compound based on the review; however, a specific BEI could not be determined due to insufficient data.") [TLVs and BEIs]

Yes

Yes

0.5 mg/m3, inhalable fraction and vapor

1 mg/m3, inhalable fraction and vapor

0.5 mg/m3

2.5 mg/m3

Excerpts from Documentation for IDLHs

Dusts are particularly irritating to the eyes and nose at concentrations greater than 1 mg/m3 but concentrations up to 2.4 mg/m3 have been tolerated by workers that have been conditioned [Clayton and Clayton 1981]. It has been reported that 401 mg/kg is the minimum lethal oral dose [Haley 1977]. [Note: An oral dose of 401 mg/kg is equivalent to a worker being exposed to about 19,000 mg/m3 for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]

0.00011 mm Hg

Explanatory Notes

VP from HSDB;

Median half-life is about 15 days; Urine concentrations reach a steady state after several months in the workplace. [TLVs and BEIs]

Reference Link #2

will not burn

Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

Yes

Chloracne

Established

Anticipated human carcinogen

Confirmed Animal

Other Poison

Uncoupler

Diseases

Occupational diseases associated with exposure to this agent:

• Acute tubular necrosis
• Chloracne
• Lymphoma, Non-Hodgkin
• Pentachlorophenol/Dinitrophenol, acute poisoning

Processes

Industrial Processes with risk of exposure:

• Applying Wood Preservatives
• Leather Tanning and Processing
• Pulp and Paper Processing

Activities

Activities with risk of exposure:

• Woodworking