2,4-dinitrophenol

Carcinogenicity

Description of key information

Two studies on dermal exposure were performed by skin painting on mice.  2,4-DNP was not effective as a tumor promotor.

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 adverse effect observed

Justification for classification or non-classification

Inconclusive

Additional information

In a study of Stenback F, Garcia H. 1975 three different experiment was performed. In the first experiment several applications by skin painting solution of 2,4- dinitrophenol in female mice, in combination with DMBA (Dimethylbenz(a)anthracene), acetone and croton oil as promoter. The treatment with the promotor 7,12-dimethyl-1,2-benzanthracene (DMBA) in acetone developed skin tumors in 23 of 30 mice (18 of 30 had papillomas an 12 of 30 had squamous cell carcinomas).In a second experiment: A single dose of 100 µg of 7,12-dimethyl-1,2-benzanthracene (DMBA) followed by application of other compounds or in a combination of other compounds were applied to female Swiss mice twice for 50 weeks. No squamous cell carcinomas were induced by any of these treatment. The incidence of papillomas was essentially no different or lower in mice receiving DMBA followed by 2,4-DNP and acetone, compared with mice receiving DMBA followed by acetone alone, and in mice receiving DMBA followed by 2,4-DNP and croton oil, compared with mice receiving DMBA followed by croton oil alone, 2,4-DNP did not appear to be a promoter for DMBA.   In the third experiment, 2,4-DNP was applied after initiation with DMBA, followed by promotion with croton oil. 2,4-DNP was applied 2 days before initiation with DMBA, during initiation, and 2 days after initiation, followed by promotion with croton oil. The incidence of papillomas was 32 of 50 in this group compared with 30 of 50 in the group receiving DMBA alone followed by croton oil. 2,4-DNP had no significant influence on DMBA initiation of tumors promoted by croton oil.

 In another study (Boutwell RK, Bosch DK. 1959), a single application of initiator 9,10-dimethyl-1,2-benzanthracene (DMBA); After, the test substance 2,4-dinitrophenol was applied to the same area of the initiator twice weekly for 12 weeks (time-weighted average (TWA) dose= 80 mg/Kg/day). Other animals were similar treated only with phenols. The survival rate after treatment with 2,4 -dinitrophenol was 100%. No evidence of skin papillomas or carcinomas was observed. As indicated in the study, 2,4-dinitrophenol is clearly not effective as a tumor promotor. The authors concluded that the introduction of nitro groups into the phenol ring destroyed the promoting effect of phenol, and that 2,4-DNP was not effective as a tumor promotor. 2,4-DNP was not tested as an initiator.