PNNL

Abstract

One federal agency has chosen to use exclusively modern SI units of radiation dose in its regulations: the FDA. While not exactly hot news, this bold move by a U.S. government agency on November 26, 1997, available at http://www.cfsan.fda.gov/~lrd/fr97123a.html, should be noted by those who wish to encourage the switch from curies, working level months, rads, rems, and roentgens to becquerels, joule hours per cubic meter, grays, sieverts, and coulombs per kilogram. The regulation is 21 CFR 179, Irradiation in the Production, Processing, and Handling of Food. Specifically, 21 CFR 179.26 (b) 8. permits meat irradiation up to 4.5 kGy for refrigerated meat and 7.0 kGy for frozen meat. Prior to the 1997 addition, radiation doses had been quoted in grays (kGy) with rad (Mrad) values in parentheses. In the 1997 addition, the Mrads disappeared.