Comparison of water quality criterion and lifetime health advisory for hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX).

The U.S. Environmental Protection Agency (USEPA) has recently recommended a lifetime health advisory (HA) for hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The purpose of this brief article is to present the basis for the calculation of the HA so that the reader can compare it with a water quality criterion (WQC) that has been proposed (E. L. Etnier, 1989, Regul. Toxicol. Pharmacol. 9, 147-157). In the earlier article, a water quality criterion of 105 micrograms/liter for RDX in drinking water was proposed, and in the present article the methodology by which USEPA calculated a lifetime HA of 2 micrograms/liter is presented. The differences in the derivation of the WQC and the HA are discussed.