CASRN 50-00-0 | DTXSID7020637

Noncancer Assessment

Reference Dose for Oral Exposure (RfD) (PDF) (17 pp, 133 K) Last Updated: 09/01/1990

System RfD (mg/kg-day) Basis PoD Composite UF Confidence
Urinary, Gastrointestinal, Other 2 x 10-1 Reduced weight gain, histopathology in rats NOAEL : 1.5 x 101
100 Medium


Reference Concentration for Inhalation Exposure (RfC) (PDF) (17 pp, 133 K)
Not assessed under the IRIS Program.


Cancer Assessment

Weight of Evidence for Cancer (PDF) (17 pp, 133 K) Last Updated: 05/01/1991

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)
  • Based on limited evidence in humans, and sufficient evidence in animals. Human data include nine studies that show statistically significant associations between site-specific respiratory neoplasms and exposure to formaldehyde or formaldehyde-containing products. An increased incidence of nasal squamous cell carcinomas was observed in long-term inhalation studies in rats and in mice. The classification is supported by in vitro genotoxicity data and formaldehyde's structural relationships to other carcinogenic aldehydes such as acetaldehyde.
  • This may be a synopsis of the full weight-of-evidence narrative.

Quantitative Estimate of Carcinogenic Risk from Oral Exposure (PDF) (17 pp, 133 K)

Not Assessed under the IRIS Program.

Quantitative Estimate of Carcinogenic Risk from Inhalation Exposure (PDF) (17 pp, 133 K)

Inhalation Unit Risk: 1.3 x 10 -5 per µg/m3
Extrapolation Method: Linearized multistage procedure, additional risk
Tumor site(s): Respiratory
Tumor type(s): Squamous cell carcinoma (Kerns et al., 1983)

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

Formaldehyde is being reassessed.

Assessment Manager(s): Thomas Bateson (, Andrew Kraft (

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 04/2022 06/2023
4 Peer Review Draft 10/2022 06/2023
7 Post Final Assessment TBD

Please note: Any future dates displayed under Release Date are estimates and subject to change.

Oct 2022: EPA’s IRIS Assessment of Formaldehyde (Inhalation). Presentation to the NASAM External Peer Review Panel (Other)

Apr 2022: IRIS Toxicological Review of Formaldehyde-Inhalation (External Review Draft, 2022) (Report)

Dec 2021: IRIS Toxicological Review of Formaldehyde-Inhalation (Interagency Science Consultation Draft, 2021) (Report)

Jun 2021: IRIS Program Outlook Jun 2021-Unsuspended Assessment (Other)

Apr 2019: IRIS Program Outlook April 2019-Suspended/Discontinued Assessment (Other)

Jun 2010: IRIS Toxicological Review of Formaldehyde (Inhalation) (External Review Draft, 2010) (Report)

May 2010: IRIS Toxicological Review of Formaldehyde (Interagency Science Consultation Draft, 2010) (Report)

Jan 2010: Formaldehyde and LeukemiA: Epidemiology, Potential Mechanisms and Implications for Risk Assessment (Journal)

Dec 2009: Statistical Inferences from Formaldehyde Dna-Protein Cross-Link Data (Journal)

Jul 2008: Analysis of the Sensitivity and Uncertainty in 2-Stage Clonal Growth Models for Formaldehyde with Relevance to Other Biologically-Based Dose Response (BBDR) Models (Report)


Oct 2005: Two-Stage Modeling of Formaldehyde-Induced Tumor Incidence in the Rat—analysis of Uncertainties (Other)

Feb 2003: IRIS Toxicological Review and Risk Characterization of Formaldehyde/Vinyl Acetate/Acetaldehyde: Based on Mode of Action (Other)

Sep 1985: Health and Environmental Effects Profile for Formaldehyde (Report)

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