Acrylonitrile Quickview (CASRN 107-13-1)

Status of Data for Acrylonitrile

File First On-Line: 09/30/1987; Last Significant Revision: 11/01/1991

Category (section)	Status	Last Revised
Oral RfD Assessment	No data	07/01/1993
Inhalation RfC Assessment	On-line	12/01/1991
Carcinogenicity Assessment	On-line	01/01/1991
Under Re-Assessment

Synonyms

107-13-1 Acritet Acrylnitril Acrylon Acrylonitrile

Acrylonitrile monomer Akrylonitryl Carbacryl Cianuro di vinile more...

Chronic Health Hazard Assessments for Noncarcinogenic Effects

Reference Dose for Chronic Oral Exposure (RfD)

Not Assessed under the IRIS Program.

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Reference Concentration for Chronic Inhalation Exposure (RfC)

Critical Effect	Point of Departure*	UF	MF	RfC
Degeneration and inflammation of nasal respiratory epithelium; hyperplasia of mucous secreting cells	LOAEL (HEC): 1.9 mg/m3	1000	1	2x10-3 mg/m3

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

• Principal and Supporting Studies (Inhalation RfC)
  • Rat 2-year inhalation study, Quast et al., 1980
• Confidence in the Inhalation RfC
  • Study -- Medium
  • Database -- Medium
  • RfC -- Medium

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Carcinogenicity Assessment for Lifetime Exposure

• Weight-of-Evidence Characterization
  • B1 (Probable human carcinogen - based on limited evidence of carcinogenicity in humans)
• Weight-of-Evidence Narrative:
  • The observation of a statistically significant increase in incidence of lung cancer in exposed workers and observation of tumors, generally astrocytomas in the brain, in studies in two rat strains exposed by various routes (drinking water, gavage, and inhalation) forms the basis for this classification.
  • 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
5.4 x10-1 per mg/kg-day	Linearized multistage procedure, extra risk

Drinking Water Unit Risks
1.5x10-5 per ug/L

Risk Level	Concentration
E-4 (1 in 10,000)	6 ug/L
E-5 (1 in 100,000)	6x10-1 ug/L
E-6 (1 in 1,000,000)	6x10-2 ug/L

• Dose-Response Data (Carcinogenicity, Oral Exposure)
  • Tumor Type: Brain and spinal cord astrocytomas, Zymbal gland carcinomas and stomach papillomas/ carcinomas
  • Test Species: Rats (Spartan Sprague-Dawley, males; Fischer 344, males; Sprague-Dawley, males)
  • Route: Oral, Drinking water
  • Reference: Biodynamics, 1980a,b; Quast et al., 1980a

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Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure

Inhalation Unit Risk(s)	Extrapolation Method
6.8 x10-5 per ug/m3	Average relative risk

Inhalation Concentrations at Specified Risk Levels

Risk Level	Concentration
E-4 (1 in 10,000)	1 ug/m3
E-5 (1 in 100,000)	1x10-1 ug/m3
E-6 (1 in 1,000,000)	1x10-2 ug/m3

• Dose-Response Data (Carcinogenicity, Inhalation Exposure)
  • Tumor Type: Respiratory cancer
  • Test Species: Humans
  • Route: Inhalation
  • Reference: O'Berg, 1980