The Office of Environmental Health Hazard Assessment (OEHHA) is releasing two draft documents for public review, summarizing the toxicity and derivation of proposed Reference Exposure Levels (RELs) for Hexamethylene Diisocyanate (HDI) and toluene. RELs are airborne concentrations of a chemical that are not anticipated to result in adverse non–cancer health effects for specified exposure durations in the general population, including sensitive subpopulations.
