0ba0c9c5_t_Red_104___Environment_Canada_Summary_table_Response
[Comment] The government has placed excessive reliance on in vitro studies (for genotoxicity), which are not relevant to human exposure to C.I. Pigment Yellow 34 and C.I. Pigment Red 104. Their concern focused particularly on the dissolved nature or test particle size of the substances used in the studies as they were of the opinion the test substances would not be relevant surrogates for the actual pigments moving through commerce. [Response] 
The results from in vitro genotoxicity testing, although not exposure routes directly relevant to human exposure, provides insight into the genotoxic potential of the pigments. Although limited data were available for the pigments themselves, positive results were obtained in in vitro assays, even in cases where strong dissolution methods were not used (i.e. Levis and Majone 1981, Venier et al. 1985). As well, in the Nestmann and Zhang 2007 study, a small increase in chromosomal aberrations was also observed although the results were not statistically significant.
Public comments for C.I. Pigment Red 104 - Environment Canada