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FDA finds no overall change in perchlorate levels in food between 2005 and 2012

Perchlorate is a naturally occurring and manmade chemical that is present in the environment and occurs in some drinking water systems and in foods. Perchlorate levels may vary widely even within a single food based on where it is grown and the amount of perchlorate in the water.

Between 2008 and 2012, the FDA collected and tested a total of 5,464 food samples for perchlorate and found no overall change in perchlorate levels across foods compared to 937 samples collected between 2005 and 2006. A further analysis of perchlorate levels per year between 2008 and 2012 also found no consistent change in perchlorate levels across foods from year to year.

The 2008 – 2012 dataset contained higher average levels of perchlorate in some foods such as bologna, salami, and collard greens, and lower average levels of perchlorate in other foods such as plain bagels, boxed macaroni and cheese, and milk chocolate, when compared to the 2005 – 2006 dataset. These differences may be due to a number of factors, including variances in the region or season when the samples were collected and/or the increase in sampling in 2008-2012.

The FDA collected these samples as part of its Total Diet Study (TDS), which analyzes samples of about 280 types of foods, including 40 types of baby food, every year from different parts of the country.

The agency used these datasets to conduct exposure assessments, which took into account average perchlorate concentrations within food categories to estimate perchlorate exposure for the populations studied. The results of the exposure assessments were published in two studies; the 2005-2006 data in 2008 (1) and the 2008-2012 data in 2016 (2).

The estimated average intakes of perchlorate for the populations studied in both these exposure assessments were below the EPA’s perchlorate Reference Dose (RfD) of 0.7 µg/kg body weight (bw)/day. For example, the estimated average intake of perchlorate for infants/toddlers based on the 2008-2012 data ranges from 0.36 to 0.48 µg/kg bw/day, approximately half the EPA’s RfD. The RfD is an estimate of a daily oral exposure to the human population (including sensitive subgroups) that is not likely to result in adverse health effects during a lifetime.

(1) Murray CW, Egan SK, Kim H, Beru N, Bolger PM. US Food and Drug Administration’s Total Diet Study: Dietary intake of perchlorate and iodine. J Expo Sci Environ Epidemiol 2008: 18:571-580.

(2) Abt E, Spungen J, Pouillot R, Gamalo-Siebers M, Wirtz M. Update on dietary intake of perchlorate and iodine from U.S. Food and Drug Administration’s Total Diet Study: 2008-2012. J Expo Sci Environ Epidemiol December 2016 (online).

For additional information, see Perchlorate Questions and Answers. 

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