Was it necessary to add Bitrex (denatonium benzoate) to automotive products?

Oregon was the first state to mandate the addition of a bitter aversive agent to consumer automotive products containing > or = 10% ethylene glycol (EG) or > or = 4% methanol (MeOH). The 1995 Toxic Household Products statute required the addition of denatonium benzoate at a concentration of 30-50 ppm with the intent to reduce the frequency of serious pediatric exposures to these products. Retrospective review included Oregon Poison Center (OPC) records of all reported pediatric (< 6 y) exposures to automotive antifreeze (EG) and windshield washer fluid (MeOH) from 1987 through 2003, OPC charts of children treated with ethanol, fomepizole, or hemodialysis for EG or MeOH poisoning from 1987 through 2002, and coroner reports of poisoning deaths for 1994-1997 to identify EG or MeOH deaths not reported to the OPC. OPC recorded 332 EG and 117 MeOH exposures among preschool children from 1987-2003 with no change in annual frequency after 1995. No child died or suffered "major" effects before or after 1995. Ten children received ethanol infusions until laboratory results were available; 9 had no detectable concentration of the suspected agent, and 1 had a sub-toxic concentration. Two children received fomepizole but had no detectable EG. No child underwent hemodialysis. Coroner reports detected no missed pediatric deaths from toxic alcohols in 1994-1997. The mandatory addition of denatonium benzoate was unnecessary as unintentional ethylene glycol or methanol exposures in pre-school age children did not cause measurable toxicity.