Perchlorate in foods not likely to present a public health threat

Jun 1 2007

The U.S. Food and Drug Administration (FDA) has released a new report, 2004-2005 Exploratory Survey Data on Perchlorate in Food and has indicated that the estimated average exposure to perchlorate in foods is well below the perchlorate reference dose (RfD) suggested by the National Academy of Sciences (NAS).

The RfD is an estimate of a daily oral exposure that is likely to be without an appreciable risk of adverse effects over a lifetime.

The highlights below are not intended to be a comprehensive summary of the FDA report or its conclusions. A complete copy of the report can be viewed at the link above and the FDA has published an updated Q&A for perchlorate on its Web site at http://www.cfsan.fda.gov/~dms/clo4qa.html.

• FDA examined 27 different kinds of foods and beverages in its survey and its updated Q&A document (Question #11) states, "perchlorate levels in the foods and beverages studied are not likely to present a public health risk."
• FDA estimates that the average exposure to perchlorate from the foods studied is less than one-tenth of the NAS reference dose. Estimated average exposure to perchlorate from the foods tested, for anyone aged 2 or above, was 0.053 micrograms per kilogram of body weight per day, well below the NAS reference dose of 0.7 micrograms per kilogram of body weight per day.
• FDA continues to recommend a healthy eating plan that emphasizes fruits, vegetables, whole grains and fat-free or low fat milk and milk products, among other foods.
• FDA did indicate that some sources of uncertainty do exist for its study:
• The foods studied account for only about one-third of U.S. diet, so true average intake of perchlorate could be higher. However, FDA strategically targeted the foods analyzed "to represent high end foods (i.e. foods that would tend to have higher concentrations of perchlorate). Thus, this 'one-third' of the diet likely represents a sizable fraction (considerably larger than 1/3) and 'scaling up' the FDA estimate by a factor of 3 would be inappropriate."
• Many of the produce samples came from regions where water sources are known to contain perchlorate and "thus perchlorate levels are likely to be biased high."

For more information on perchlorate, please visit the Council on Water Quality Web site, http://www.councilonwaterquality.org/ or contact the CWQ news bureau at (916) 448-3152.

The Council on Water Quality is supported by Lockheed Martin, Aerojet, Tronox and American Pacific Corporation. These companies have worked cooperatively with the U.S. Environmental Protection Agency to increase scientific and medical understanding of perchlorate's risk to human health.