Peracetic acid

Carcinogenicity

Key value for chemical safety assessment

Carcinogenicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available data on carcinogenicty of peracetic acid do not meet the criteria for classification according to Regulation (EC) 1272/2008, as amended for the seventeenth time in Regulation (EU) 2021/849, and are therefore conclusive but not sufficient for classification.

Additional information

In general, Peracetic acid has no obvious structural alerts for carcinogenicity and is degraded to innocuous metabolites (water, acetic acid, oxygen).

Thus, no valid carcinogenicity study is available. According to the relevant REACH Annex testing does not appear scientifically necessary because peracetic acid is not classified as mutagen category 1, 2 or 3 and there is no evidence from the repeated dose study(ies) that it is able to induce hyperplasia and/or pre-neoplastic lesions.

In the available subchronic study in rats (Gaou, 2003), the observed toxicological effects can be attributed to the locally irritating properties and the acute toxicity of peracetic acid, i.e. irritating or corrosive effects at the site of first contact (i.e. the mucous membranes of the stomach) and decomposition to hydrogen peroxide, oxygen, and acetic acid. There are no indications of pre-neoplastic lesions and/or hyperplasia in the GI tract of the treated rats which might progress to neoplastic lesions after prolonged period of action. However, it is well known that substances which induce (sustained) local irritation can accelerate the formation of tumours at the sites of contact. This represents an effect secondary to local irritation, rather than indicating a direct carcinogenic effect. Furthermore, this is a common and general effect of many substances with irritating or corrosive properties.

A tumour initiation study was conducted in mice (Bock et al., 1975), which however is not considered valid because of several methodological and reporting deficiencies. Only females, only 30 animals per group were used; examinations were only once a week and only for skin tumours without complete gross necropsy; only one dose of peracetic acid in water without initiator was used; the negative control mice do not seem to have been treated in the same manner as the other groups, in particular the two solvents (acetone and water) seem not to have been applied. Historical control data on tumour incidence in Swiss mice is considerably higher than claimed by the author. The classification of tumours used does not correspond to the current standards.

In this study, peracetic acid was reported to act as a tumour promotor on mouse skin after initiation with DMBA (9,10-dimethyl-1,2-benzanthracene). This effect, however, is caused by sustained irritation which is due to the long-term exposure at irritating concentrations of peracetic acid in combination with a tumour initiator and is considered to be a known reaction towards corrosives, i.e. a mechanism not specific or unique to peracetic acid. If exposure is limited to sub-irritant concentrations in the absence of a tumour initiator, then there is no concern for a possible tumour-promoting effect of equilibrium peracetic acid A. Tumour promotion, as evaluated in the presence of a tumor initiator, is not likely to occur in actual human exposure scenarios.