Arsenic, Inorganic
CASRN 7440-38-2 | DTXSID4023886
Noncancer Assessment
Reference Dose for Oral Exposure (RfD) (PDF)
(29 pp, 186 K)
Last Updated: 09/01/1991
| System | RfD (mg/kg-day) | Basis | PoD | Composite UF | Confidence |
|---|---|---|---|---|---|
| Cardiovascular, Dermal | 3 x 10 -4 | Hyperpigmentation, keratosis and possible vascular complications |
NOAEL
:
8
x 10-4 mg/kg-day |
3 | Medium |
Reference Concentration for Inhalation Exposure (RfC) (PDF)
(29 pp, 186 K)
Not assessed under the IRIS Program.
Cancer Assessment
Weight of Evidence for Cancer (PDF)
(29 pp, 186 K)
Last Updated: 06/01/1995
| WOE Characterization | Framework for WOE Characterization |
|---|---|
| A (Human carcinogen) | Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) |
- Based on sufficient evidence from human data. An increased lung cancer mortality was observed in multiple human populations exposed primarily through inhalation. Also, increased mortality from multiple internal organ cancers (liver, kidney, lung, and bladder) and an increased incidence of skin cancer were observed in populations consuming drinking water high in inorganic arsenic.
- This may be a synopsis of the full weight-of-evidence narrative.
Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (29 pp, 186 K)
Oral Slope Factor:
1.5
per mg/kg-day
Drinking Water Unit Risk:
5
x 10-5
per µg/L
Extrapolation Method: Time- and dose-related formulation of the multistage model
Tumor site(s): Dermal
Tumor type(s): Skin cancer (Tseng, 1977; Tseng et al., 1968; U.S. EPA, 1988)
Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (29 pp, 186 K)
Inhalation Unit Risk:
4.3
x 10-3
per µg/m3
Extrapolation Method: Absolute-risk linear model
Tumor site(s): Respiratory
Tumor type(s): Lung cancer (Brown and Chu, 1983a,b,c; Lee-Feldstein, 1983; Higgins, 1982; Enterline and Marsh, 1982)
Program Outlook Details
| Public Assessment Materials | Date |
|---|---|
| Problem Formulation Materials/IRIS Assessment Plan | Nov-2012 |
| Preliminary Assessment Materials/Systematic Review Protocol | May-2019 |
| Public Comment | Oct-2023 |
| External Peer Review | FY24/Q1 |
| Post Final Assessment | TBD |
Note: Any future dates displayed in the table above should be considered estimates and are subject to change. Once the external peer review is complete, estimated dates for release of the final assessment will be published. For the latest information on the status of this assessment, please refer to the IRIS Program Outlook. To access assessment documents, meeting materials or other supporting documents related to this assessment, visit the Chemical Documents tab. For more information about the development process, visit the IRIS Process page.
Oct 2023: IRIS Toxicological Review of Inorganic Arsenic (Public Comment and External Review Draft) (Report)
Apr 2014: IRIS Toxicological Review of Inorganic Arsenic (Preliminary Assessment Materials, 2014) (Report)
Jan 2013: Inorganic Arsenic Workshop (Jan 2013) (Other)
Sep 2012: Inorganic Arsenic Meetings & Webinars (Sep 2012 - Jul 2019) (Other)
Feb 2010: IRIS Toxicological Review of Inorganic Arsenic (Cancer) (External Review Draft, 2010) (Report)
Jul 2005: IRIS Toxicological Review of Ingested Inorganic Arsenic (SAB External Review Draft, 2005) (Report)
- Human Health Benchmarks for Pesticides (HHBP). This database provides human health benchmarks for pesticides that may be present in drinking water.
- Office of Pesticide Programs Pesticide Chemical Search. This database provides links to health effects information and registration status for pesticides.
- Chemistry Dashboard. This database provides information on chemical structures, experimental and predicted physicochemical, and toxicity data.
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Critical Effect Systems
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Chemical Structure for
Arsenic, Inorganic
