Pentachlorophenol Quickview (CASRN 87-86-5)

Status of Data for Pentachlorophenol

File First On-Line: 01/31/1987; Last Significant Revision: 03/01/1991

Category (section)	Status	Last Revised
Oral RfD Assessment	On-line	02/01/1993
Inhalation RfC Assessment	No data
Carcinogenicity Assessment	On-line	07/01/1993
Under Re-Assessment

Synonyms

Chem-tol Cryptogil ol Dowcide 7 DP-2, technical Durotox Glazd penta

1-Hydroxy- 2,3,4,5,6-pentachlorobenzene lauxtol a Liroprem NCI-C55389 PCP more...

Chronic Health Hazard Assessments for Noncarcinogenic Effects

Reference Dose for Chronic Oral Exposure (RfD)

Critical Effect	Point of Departure*	UF	MF	RfD
Liver and kidney pathology	NOAEL : 3 mg/kg-day	100	1	3 x10-2 mg/kg-day

* The Point of Departure listed serves as a basis from which the Oral RfD was derived. See Discussion of Conversion Factors and Assumptions for more details.

• Principal and Supporting Studies (Oral RfD)
  • Rat oral chronic study, Schwetz et al., 1978
• Confidence in the Oral RfD
  • Study -- High
  • Database -- Medium
  • RfD -- Medium

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Reference Concentration for Chronic Inhalation Exposure (RfC)

Not Assessed under the IRIS Program.

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Carcinogenicity Assessment for Lifetime Exposure

• Weight-of-Evidence Characterization
  • B2 (Probable human carcinogen - based on sufficient evidence of carcinogenicity in animals)
• Weight-of-Evidence Narrative:
  • The classification is based on inadequate human data and sufficient evidence of carcinogenicity in animals: statistically significant increases in the incidences of multiple biologically significant tumor types (hepatocellular adenomas and carcinomas, adrenal medulla pheochromocytomas and malignant pheochromocytomas, and/or hemangiosarcomas and hemangiomas) in one or both sexes of B6C3F1 mice using two different preparations of pentachlorophenol (PeCP). In addition, a high incidence of two uncommon tumors (adrenal medulla pheochromocytomas and hemangiomas/hemangiosarcomas) was observed with both preparations. This classification is supported by mutagenicity data, which provides some indication that PeCP has clastogenic potential.
  • This may be a synopsis of the full weight-of-evidence narrative. See IRIS Summary.

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Quantitative Estimate of Carcinogenic Risk from Oral Exposure

Oral Slope Factor(s)	Extrapolation Method
1.2 x10-1 per mg/kg-day	Linearized multistage procedure

Drinking Water Unit Risks
3x10-6 per µg/L

Risk Level	Concentration
E-4 (1 in 10,000)	3x101 µg/L
E-5 (1 in 100,000)	3 µg/L
E-6 (1 in 1,000,000)	3x10-1 µg/L

• Dose-Response Data (Carcinogenicity, Oral Exposure)
  • Tumor Type: Hepatocellular adenoma/carcinoma, pheochromocytoma/ malignant pheochromocytoma, hemangiosarcoma/ hemangioma (pooled incidence)
  • Test Species: Mouse/ B6C3F1, female
  • Route: Oral, Diet
  • Reference: NTP, 1989

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Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure

• Not Assessed under the IRIS Program.