The Facts About Perchlorate and Food

On November 26, 2004, the Food and Drug Administration (FDA) posted new information on its Web site regarding exploratory data on perchlorate and food, particularly milk and lettuce (www.cfsan.fda.gov/~dms/clo4data.html). Placing the new detections in perspective, the FDA stated, "These data are exploratory and should not be understood to be a reflection of the distribution of perchlorate in the U.S. food supply."

The agency also provided a dietary recommendation for the general public: "Until more is known about the health effects of perchlorate and its occurrence in food, FDA continues to recommend that consumers eat a balanced diet, choosing a variety of foods that are low in trans fat and saturated fat, and rich in high fiber grains, fruits and vegetables. FDA does not recommend at this time that consumers should alter their infants' and children's diets and eating habits to avoid exposure to perchlorate". (bold added)

Some important considerations regarding this information:

  1. Food and milk are safe, and continue to be recommended as part of a healthy diet.

    • FDA findings that perchlorate has been detected in milk and some agricultural products are consistent with reports issued earlier this year. A press release from the American Thyroid Association notes the weight of scientific evidence indicates it's highly unlikely the levels of perchlorate detected have any measurable health effect.
    • FDA has recommended that no one should change their diet. FDA, as the agency with primary jurisdiction over food safety, recommends milk and vegetables as important parts of a healthy diet. See FDA's Questions and Answers…
    • To put these most recent findings in common sense terms, a person would drown in milk, for example, before perchlorate could pose a health risk. The highest level detected in some samples of milk was 11.3 parts per billion (ppb). According to Dr. Michael Payne, a toxicologist at the University of California at Davis, a person would have to drink an impossible 2,000 eight-ounce glasses of milk a day at least, for weeks or months, before there could be any risk of adverse health effects from perchlorate. Read more about health effects…

  2. Levels of perchlorate found in the FDA research have no measurable effect on the body, and are indistinguishable from the presence of natural elements in a serving of common vegetables.

    • Milk, lettuce, broccoli and other products have always contained naturally-occurring compounds called nitrates and thiocyanates, which are considered safe at the levels found in the environment. These elements act exactly the same way as perchlorate in the body, and like perchlorate, they have no adverse impact on the body at low levels. At levels found naturally in foods, they can partially block the thyroid gland's ability to absorb iodine, which it uses to make hormones. It is a widely-held scientific view that this in itself is harmless.
    • This iodine blockage is a natural process that happens every day. As a result of a normal and healthy diet, 50 to 70 percent of the average person's iodine is blocked from their thyroid every day. Experts report that people can experience up to 90 percent of this blockage for a long period of time before there is any risk of negative effects.
    • Perchlorate has no measurable effect on the body at levels below 245 ppb. Even at 245 ppb, perchlorate's incremental contribution to blocking iodine would not exceed two-to-three percent. In other words, at the levels found in FDA's research, perchlorate plays an almost insignificant role in blocking iodine compared to the safe and healthy impact of foods in our everyday diet.

  3. Detection of perchlorate in more places underscores the need to get the science right when taking regulatory action.

    • New analytical tools have led to the discovery of previously undetectable levels of perchlorate. In some cases, even a source for the presence of the compound is unknown. This discovery - combined with the widely-held scientific view that exposure to the trace amounts now being detected is unlikely to pose a health risk - led the federal government to undertake the deliberative NAS process to obtain the best possible data for setting standards.
    • At the request of the EPA NAS convened a world-class panel of experts to review the best available science on the issue. Fortunately, there are 50 years of research available; dating back to the time perchlorate was used as a medicine in dosages much higher than those being found in the environment. Read More…
    • After nearly two years of reviewing and analyzing the most recent scientific studies, research and data on perchlorate, the NAS issued its report on the health implications of perchlorate in January 2005. The NAS committee concluded that a reference dose of perchlorate at 0.0007 milligrams per kilogram per day is appropriate and protective for all populations, including the most sensitive population - the fetuses of pregnant women who might have hypothyroidism or iodide deficiency.
    • In February 2005, the EPA established its official reference dose of perchlorate at 0.0007 milligrams per kilogram per day, and translated that number to a Drinking Water Equivalent Level of 24.5 ppb.