Americans' exposure to perchlorate in food is below the safe daily dose recommended by the National Research Council, according to a preliminary estimate from FDA. The study released last week by FDA's Center for Food Safety & Applied Nutrition analyzed 27 foods and beverages from areas with water known to be contaminated with perchlorate. The chemical is a water-soluble component of rocket fuel that interferes with thyroid function. FDA found that the average daily dose of perchlorate for the U.S. population age two years and older was 0.053 ??g per kg of body weight. This is lower than the 0.7 ??g/kg safe daily dose that NRC recommended in 2005. The analysis examined perchlorate levels in milk, fruit and fruit juices, vegetables, grains, and farmed fish and shrimp. FDA says it will publish a comprehensive, nationally representative assessment of dietary exposure to perchlorate later this year. EPA will use these data as it decides whether to establish a national limit for allowable levels of perchlorate in public drinking water supplies (C&EN, May 14, page 39). The FDA report is available at www.cfsan.fda.gov/~dms/clo4ee.html.