Development and Uses of Acute Reference Values
George Woodall, PhD
National Center for Environmental Assessment, US EPA

There is a need for health-based reference (guideline) values to determine “safe” levels for exposure to a chemical (or mixture of chemicals) for a number of purposes, including regulatory, emergency response, and safeguarding public health. Many such values have been developed for a number of different exposure scenarios. Several different organizations have been developing less-than-lifetime (acute and sub-chronic) reference values, each with its own methods for creating those values, organizational history, and applicability for the use of those values. This talk introduces and compares the “alphabet soup” associated with these organizations (EPA, NAC/AEGL, AIHA, ATSDR, OSHA, NIOSH) and with their respective values (ARE, AEGL, ERPG, MRL, TLV, IDLH, STEL, etc.), then discusses how each is intended to be used. The rather recent efforts of the US EPA, and in particular NCEA, to develop a set of less-than-lifetime reference values will also be discussed, along with how that effort fits in with the existent sets of values. [This abstract does not necessarily reflect EPA policy.]