- IRIS Summary (PDF) (23 pp, 162 K)
- Status: Acrylonitrile is in step 4 at this time; see Quick Check.
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||
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 (US 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.
Oral Slope Factor:
5.4 x10 -1 per mg/kg-day
Drinking Water Unit Risk: 1.5 x10 -5 per µg/L
Extrapolation Method: Linearized multistage procedure, extra risk
Tumor site(s): Other, Nervous, Gastrointestinal
Tumor type(s): Brain and spinal cord astrocytomas, Zymbal gland carcinomas and stomach papillomas/ carcinomas (Biodynamics, 1980a,b Quast et al., 1980a)
Inhalation Unit Risk:
6.8 x10 -5 per µg/m3
Extrapolation Method: Average relative risk
Tumor site(s): Respiratory
Tumor type(s): Respiratory cancer (O'Berg, 1980)
Acrylonitrile is being reassessed.
|Step||Assessment Materials Released to the Public||Release Date||Public Meeting Date|
|1||Problem Formulation Materials||N/A||N/A|
|1||Preliminary Assessment Materials||N/A||N/A|
|4||Public Comment Draft||TBD||TBD|
|4||Peer Review Draft||TBD||TBD|
|7||Post Final Assessment||TBD|
Please note: Any future dates displayed under Release Date are estimates and subject to change.
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