| | Group 1 | Carcinogenic to humans | 107 agents |
| Group 2A | Probably carcinogenic to humans | 58 |
| Group 2B | Possibly carcinogenic to humans | 249 |
| Group 3 | Not classifiable as to its carcinogenicity to humans | 512 |
| Group 4 | Probably not carcinogenic to humans | 1 |
|
For definitions of these groups, please see the Preamble. |
| It is strongly recommended to consult the complete Monographs on these agents, the publication date, and the list of studies considered. Significant new information might support a different classification. |
| For agents that have not been classified, no determination of non-carcinogenicity or overall safety should be inferred. |