CASRN 107-13-1 | DTXSID5020029

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (23 pp, 162 K)
Not assessed under the IRIS Program.


Reference Concentration for Inhalation Exposure (RfC) (PDF) (23 pp, 162 K) Last Updated: 11/01/1991

System RfC (mg/m3) Basis PoD Composite UF Confidence
Respiratory 2 x 10-3 Degeneration and inflammation of nasal respiratory epithelium; hyperplasia of mucous secreting cells LOAEL (HEC): 1.9
1000 Medium


Cancer Assessment

Weight of Evidence for Cancer (PDF) (23 pp, 162 K) Last Updated: 09/30/1987

WOE Characterization Framework for WOE Characterization
B1 (Probable human carcinogen - based on limited evidence of carcinogenicity in humans) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986)
  • 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.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (23 pp, 162 K)

Oral Slope Factor: 5.4 x 10 -1 per mg/kg-day
Drinking Water Unit Risk: 1.5 x 10 -5 per µg/L
Extrapolation Method: Linearized multistage procedure, extra risk
Tumor site(s): Gastrointestinal, Other, Nervous
Tumor type(s): Brain and spinal cord astrocytomas, Zymbal gland carcinomas and stomach papillomas/ carcinomas (Biodynamics, 1980a,b Quast et al., 1980a)

Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (23 pp, 162 K)

Inhalation Unit Risk: 6.8 x 10 -5 per µg/m3
Extrapolation Method: Average relative risk
Tumor site(s): Respiratory
Tumor type(s): Respiratory cancer (O'Berg, 1980)

Additional EPA toxicity information may be available by visiting the following sites:

Note: The acrylonitrile (re)assessment has been discontinued. A new/updated assessment will not be added to the IRIS database at this time.

Assessment Manager(s): Andrew Kraft (, Dahnish Shams (

Step Assessment Materials Released to the Public Release Date Public Meeting Date
4 Peer Review Draft 06/2011 N/A
  Discontinued 12/2018  

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