California’s Office of Environmental Health Hazard Assessment (OEHHA) has approved its proposed No Significant Risk Level (NSRL) for Diisononyl phthalate (DINP).
The agency proposed its safe harbor level of 146 micrograms per day in December 2014.
Several interested parties that submitted public comments regarding the proposed NSRL argued that the studies OEHHA relied upon in the agency’s risk assessment is based on data that is not relevant to humans.
“The OEHHA derivation of an NSRL for DINP includes mononuclear cell leukemia (MNCL) data from these two chronic studies. The NSRL should not be based on these data because, as discussed below, MNCL observed in F344 rats is not relevant to humans and therefore is not an appropriate animal model of carcinogenesis,” The American Chemistry Council wrote in omments submitted to OEHHA in March 2015.
The trade group argues that “MNCL in F344 rats is a common finding in aging F344 rats and that the increased incidence in rats treated with DINP is not relevant to humans.”
Despite heavy opposition to the NSRL, OEHHA submitted the regulation to the state’s Office of Administrative Law, which approved the Safe Harbor Level on Feb. 8.
The American Chemistry Council challenged the December 2013 listing of DINP by the state’s Carcinogen Identification Committee (CIC) last year, but a Sacramento Superior Court Judge ruled the CIC and OEHHA did not abuse their discretion by listing the chemical.
The trade group filed an appeal following the ruling.
The DINP NSRL takes effect on April 1, 2016.