- IRIS Summary (PDF) (20 pp, 147 K)
Reference Dose for Oral Exposure (RfD) (PDF) (20 pp, 147 K)
Not assessed under the IRIS Program.
Reference Concentration for Inhalation Exposure (RfC) (PDF) (20 pp, 147 K)
last updated: 10/01/1991
|System||RfC (mg/m3)||Basis||PoD||Composite UF||Confidence|
|Nervous, Respiratory||9 x 10-3||Degeneration of olfactory epithelium||
Weight of Evidence for Cancer (PDF) (20 pp, 147 K)
last updated: 06/30/1988
|WOE Characterization||Framework for WOE Characterization|
|B2 (Probable human carcinogen - based on sufficient evidence of carcinogenicity in animals)||Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986)|
- Based on increased incidence of nasal tumors in male and female rats and laryngeal tumors in male and female hamsters after inhalation exposure.
- This may be a synopsis of the full weight-of-evidence narrative.
Not Assessed under the IRIS Program.
Inhalation Unit Risk:
2.2 x 10 -6 per µg/m3
Extrapolation Method: Linearized multistage-variable exposure input form (extra risk)
Tumor site(s): Respiratory
Tumor type(s): Nasal squamous cell carcinoma or adenocarcinoma (Woutersen and Appleman, 1984)
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