In an article published on September 11, 2017 in the peer-reviewed journal Scientific Reports, Enrico Campioli and colleagues from the Research Institute of the McGill University Health Centre, Montréal, Québec, Canada, reported that exposure of pregnant rats to the plasticizer 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH, CAS 166412-78-8) caused liver- and testis-related impairments in the male offspring.
Pregnant dams were exposed orally to 1, 10, or 100 mg/kg of DINCH, the lower dose corresponding to that recommended by the European Food Safety Authority (EFSA) as the tolerable daily intake (TDI). In the male offspring’s liver, effects such as reduced bilirubin levels and albumin/globulin ratio were observed, indicating an “impaired liver metabolic capacity.” Concerning the effects on the male reproductive system, the McGill researchers observed reduced circulating testosterone levels as well as changes in seminal vesicles along with testicular atrophy, what they regarded as signs of “premature aging of the testes.” Based on their results, they called for further studies “to determine the long term consequences of DINCH exposure, and in particular its capacity to induce premature aging of the male reproductive system.”
Two scientists from BASF, Rainer Otter and Angelika Langsch, criticized the McGill study as ‘flawed,’ as reporter Emma Davies summarized in an article published on October 11, 2017 by regulatory news provider Chemical Watch. BASF has been marketing DINCH since 2002 as a safe replacement for several phthalate plasticizers, in particular diethyl hexyl phthalate (DEHP, CAS 117-81-7). In response to the published study, Otter and Langsch said that “the data presented by the authors of this study perfectly confirm at low dose levels what our data, which have been reviewed by competent authorities around the world, indicate at ten times higher dose levels and significantly longer exposure times, that DINCH is a product that does not interfere with testicular function and metabolism.” They further dismissed the reported effects as “either physiologic adaptive responses or ‘toxicologically not meaningful,’” and, in response to the call for more studies, maintained that “there are [already] enough data supporting the substance’s safety.”
Emma Davies (October 11, 2017). “BASF and McGill team clash again over DINCH data.” Chemical Watch
Campioli, E., et al. (2017). “Effect of prenatal DINCH plasticizer exposure on rat offspring testicular function and metabolism.” Scientific Reports 7:11072.