On April 8, 2016, the California Office of Environmental Health Hazard Assessment published a proposed warning level for ethylene glycol of 8,700 micrograms per day. The deadline for public comments is May 23, 2016.
Ethylene glycol, used in antifreeze products and other applications, was listed as a reproductive toxicant via the authoritative bodies mechanism on June 19, 2015 — meaning that the warning requirement for the substance goes into effect on June 19, 2016. Significantly, the listing was confined to the oral route of exposure.
Even so, the listing presented some scientific controversy. Notwithstanding a number of studies showing that no reproductive effects would be likely to be seen in humans, OEHHA relied on rodent studies. Rodent metabolism of ethylene glycol is markedly different, and more sensitive to the substance’s effects, than human metabolism.
Of the warning levels established by OEHHA for Proposition 65 chemicals, this one is among the highest. That fact perhaps will relegate this substance to a low-level interest for enforcement.