Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock ( Lock A locked padlock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

  • Environmental Topics
  • Laws & Regulations
  • Report a Violation
  • About EPA
IRIS
Contact Us

Advanced Search

Searches using filters for organ/system affected are limited to effects (or tumor sites) used to derive the RfD, RfC, oral slope factor, or inhalation unit risk. Other effects associated with chemicals in the IRIS database that were not used as the basis for a toxicity value are not searchable with organ/system filters. IRIS Advanced Search searches only final IRIS assessments; to look for information on draft assessments, see Quick Check: Assessments in Development. Additional information can be downloaded below by clicking on the “Export to Excel” feature.

  • Chemical Details
  • RfD Toxicity Values
  • RfC Toxicity Values
  • WOE Details
  • WOE Toxicity Values
  • Chemical Revision History

WOE Details

A basic version of this table is available.
ROW CHEMICAL NAME CASRN ROUTE WOE DESCRIPTION WOE TITLE WOE NARRITIVE
1 Acenaphthylene 208-96-8 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Based on no human data and inadequate data from animal bioassays.
2 Acephate 30560-19-1 Undefined C (Possible human carcinogen) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) The classification is based on increased incidence of hepatocellular carcinomas and adenomas in female mice.
3 Acetaldehyde 75-07-0 None 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.
4 Acetone 67-64-1 Undefined Data are inadequate for an assessment of human carcinogenic potential Revised Draft Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1999) In accordance with the Draft Revised Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1999) data are inadequate for an assessment of the human carcinogenic potential of acetone.
5 Acetonitrile 75-05-8 Undefined Carcinogenic potential cannot be determined Proposed Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1996) Under the Proposed Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1996), the carcinogenic potential of ACN following inhalation, oral, or dermal exposure is best characterized as "cannot be determined because the existing evidence is composed of conflicting data (e.g., some evidence is suggestive of carcinogenic effects, but other equally pertinent evidence does not confirm any concern)."
6 Acetonitrile 75-05-8 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Under the Proposed Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1996), the carcinogenic potential of ACN following inhalation, oral, or dermal exposure is best characterized as "cannot be determined because the existing evidence is composed of conflicting data (e.g., some evidence is suggestive of carcinogenic effects, but other equally pertinent evidence does not confirm any concern)."
7 Acetophenone 98-86-2 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Based on no human data and no animal data.
8 Acetyl chloride 75-36-5 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) No human data or animal data.
9 Acrolein 107-02-8 Undefined Data are inadequate for an assessment of human carcinogenic potential Revised Draft Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1999) Under the Draft Revised Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1999), the potential carcinogenicity of acrolein cannot be determined because the existing data are inadequate for an assessment of human carcinogenic potential for either the oral or inhalation route of exposure. There are no adequate human studies of the carcinogenic potential of acrolein. Collectively, experimental studies provide inadequate evidence that acrolein causes cancer in laboratory animals.
10 Acrylamide 79-06-1 Combined Likely to be carcinogenic to humans Guidelines for Carcinogen Risk Assessment (U.S. EPA, 2005) In accordance with the Guidelines for Carcinogen Risk Assessment U.S. EPA, 2005, acrylamide (AA) is characterized as "likely to be carcinogenic to humans."
11 Acrylonitrile 107-13-1 Undefined 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.
12 Adiponitrile 111-69-3 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) No human and no animal cancer data were available. Adiponitrile was negative for mutagenicity in Salmonella with and without activation.
13 Aldicarb 116-06-3 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Aldicarb was not found to induce statistically significant increases in tumor incidence in mice or rats in feeding studies or mice in a skin painting study. In the feeding studies there were, however, significant trends in pituitary tumors in female rats and fibrosarcomas in the male mouse. This evidence, together with the fact that less than maximum tolerated doses were used, indicates that the available assays are inadequate to assess the carcinogenic potential of aldicarb.
14 Aldrin 309-00-2 Undefined B2 (Probable human carcinogen - based on sufficient evidence of carcinogenicity in animals) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Orally administered aldrin produced significant increases in tumor responses in three different strains of mice in both males and females. Tumor induction has been observed for structurally related chemicals, including dieldrin, a metabolite.
15 Allyl chloride 107-05-1 Undefined C (Possible human carcinogen) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Classification is based on a low (but biologically important) incidence of forestomach tumors in female mice and positive results in a variety of genetic toxicity tests. Allyl chloride is an alkylating agent and structurally related to probable human carcinogens.
16 4-Aminopyridine 504-24-5 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) No human data and no animal data available.
17 Ammonium acetate 631-61-8 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) No human data and no animal data
18 Ammonium methacrylate 16325-47-6 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) No human data and no animal data
19 Aniline 62-53-3 Undefined B2 (Probable human carcinogen - based on sufficient evidence of carcinogenicity in animals) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Induction of tumors of the spleen and the body cavity in two strains of rat, and some supporting genetic toxicological evidence.
20 Anthracene 120-12-7 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Based on no human data and inadequate data from animal bioassays.
21 Apollo 74115-24-5 Undefined C (Possible human carcinogen) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Based on an increase in thyroid gland follicular cell tumors in male rats and supportive findings in pituitary/thyroid hormone activity.
22 Aramite 140-57-8 Undefined B2 (Probable human carcinogen - based on sufficient evidence of carcinogenicity in animals) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Based on no human data and sufficient data from animal bioassays including increased incidence of liver tumors and/or neoplastic nodules in three strains of male and female rats and males of one strain of mice, and extrahepatic biliary system tumors in dogs following chronic oral exposure.
23 Arsenic, Inorganic 7440-38-2 Undefined Carcinogenic to humans Guidelines for Carcinogen Risk Assessment (U.S. EPA, 2005) Bladder and lung cancer are acknowledged as known hazard outcomes for inorganic arsenic (ATSDR, 2007; ATSDR, 2016; Health Canada, 2006; IARC, 2004; IARC, 2012; NRC, 2013; NTP, 2016; WHO, 2011; WHO, 2011), and the strength of evidence for these health outcomes was considered robust (as described in Section 3.2 and Appendix A of the IRIS Toxicological Review). Bladder cancer and lung cancer were classified as carcinogenic to humans in the 1995 IRIS Toxicological Review based on epidemiologic evidence (U.S. EPA, 1995), and that classification is retained in the current assessment.
24 Asbestos 1332-21-4 Undefined A (Human carcinogen) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Observation of increased mortality and incidence of lung cancer, mesotheliomas and gastrointestinal cancer in occupationally exposed workers are consistent across investigators and study populations. Animal studies by inhalation in two strains of rats showed similar findings for lung cancer and mesotheliomas. Animal evidence for carcinogenicity via ingestion is limited (male rats fed intermediate-range chrysotile fibers; i.e., >10 um length, developed benign polyps), and epidemiologic data in this regard are inadequate.
25 Assure 76578-14-8 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Based on no human data and inadequate animal data.
26 Azobenzene 103-33-3 Undefined B2 (Probable human carcinogen - based on sufficient evidence of carcinogenicity in animals) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Azobenzene induced invasive sarcomas in the spleen and other abdominal organs in male and female F344 rats following dietary administration. It is genotoxic and may be converted to benzidine, a known human carcinogen, under the acidic conditions in the stomach.
27 Barium and Compounds 7440-39-3 Inhalation Carcinogenic potential cannot be determined Proposed Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1996) Under EPA's 1986 Guidelines for Carcinogen Risk Assessment, barium would be classified as Group D, not classifiable as to human carcinogenicity. Under the Proposed Guidelines for Carcinogenic Risk Assessment (U.S. EPA, 1996), barium is considered not likely to be carcinogenic to humans following oral exposure and its carcinogenic potential cannot be determined following inhalation exposure.
28 Barium and Compounds 7440-39-3 Undefined D (Not classifiable as to human carcinogenicity) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Under EPA's 1986 Guidelines for Carcinogen Risk Assessment, barium would be classified as Group D, not classifiable as to human carcinogenicity. Under the Proposed Guidelines for Carcinogenic Risk Assessment (U.S. EPA, 1996), barium is considered not likely to be carcinogenic to humans following oral exposure and its carcinogenic potential cannot be determined following inhalation exposure.
29 Barium and Compounds 7440-39-3 Oral Not likely to be carcinogenic to humans Proposed Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1996) Under EPA's 1986 Guidelines for Carcinogen Risk Assessment, barium would be classified as Group D, not classifiable as to human carcinogenicity. Under the Proposed Guidelines for Carcinogenic Risk Assessment (U.S. EPA, 1996), barium is considered not likely to be carcinogenic to humans following oral exposure and its carcinogenic potential cannot be determined following inhalation exposure.
30 Bentazon (Basagran) 25057-89-0 Undefined E (Evidence of non-carcinogenicity for humans) Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) Under EPA's 1986 Guidelines for Carcinogen Risk Assessment, Bentazon would be classified as evidence of non-carcinogenicity for humans, or a Group E chemical. Under EPA's proposed guidelines for carcinogen risk assessment (U.S. EPA, 1996), Bentazon would be characterized as not likely to be carcinogenic to humans by any route of exposure.
31 Bentazon (Basagran) 25057-89-0 Undefined Not likely to be carcinogenic to humans Proposed Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1996) Under EPA's 1986 Guidelines for Carcinogen Risk Assessment, Bentazon would be classified as evidence of non-carcinogenicity for humans, or a Group E chemical. Under EPA's proposed guidelines for carcinogen risk assessment (U.S. EPA, 1996), Bentazon would be characterized as not likely to be carcinogenic to humans by any route of exposure.
32 Benz[a]anthracene