TM The ToxGuide is developed to be used as a pocket guide. Tear off at perforation and fold along lines. Toxicokinetics and Sources of Exposure Normal Human Environmental Levels Levels/Biomarkers TM General Populations Toxicokinetics Environmental Levels ToxGuide ƒ Human exposure to perchlorate is expected ƒ Perchlorate appears to be readily absorbed Food to occur through the ingestion of food and by the digestive system after oral exposure ƒ Perchlorate has been found in a wide for milk. The Food and Drug Administration and enters the bloodstream within a few variety of foods consumed by the U.S. (FDA) recently estimated that the US hours of ingestion. population. The FDA’s Total Diet Study population ingests from 0.08 to ƒ Perchlorate is rapidly taken up into the revealed that 74% of the foods analyzed Perchlorate 0.39 µg/kg/day perchlorate from food thyroid gland by an active transport had at least one sample of detected items. and mechanism. perchlorate. Estimation of dietary intake ƒ Human exposure to perchlorate also can showed the lowest intake to be 0.08– ƒ Perchlorate does not appear to be modified occur through the ingestion of water, as it 0.11 μg/kg/day for males aged 25–30 years Perchlorate Salts in the body, either by degradation or has been found in drinking water supplies, and the highest intake to be 0.35– covalent binding. CAS# 107-02-8 tap water samples, and groundwater at 0.39 μg/kg/day for children 2 years old. September 2008 some locations. ƒ Perchlorate is rapidly eliminated from the The majority of the perchlorate estimated body in the urine with half-times of intake by infants 6-11 months comes from ƒ Efforts are being made to determine the approximately 8-12 hours in humans. baby foods, such as infant formula and relative contribution of perchlorate from However, recent studies have shown dairy foods. Dairy foods contribute about food and water. widespread exposure to low levels of half of the total estimated daily intake of ƒ Sources of perchlorates include rocket fuel, perchlorate by the general population, so perchlorate by children 2, 6, and 10 years flares, gunpowder, temporary adhesives, exposure may be frequent. old. Vegetables and dairy foods combined U.S. Department of Health and electrolysis baths, batteries, drying agents, account for between 46% and 59% of the etching agents, oxygen generating systems, total estimated intake of perchlorate by Human Services matches, chlorine and chlorine based Normal Human Levels teenagers and adults. Public Health Service cleaners, and pool chlorination chemicals. Urine Water Agency for Toxic Substances ƒ Chewing tobacco could be a source of ƒ In 2,820 participants in a national survey ƒ EPA collected drinking water occurrence and Disease Registry exposure because perchlorate has been (2001-2002), the geometric mean in urine data for perchlorate from 3,865 Public www.atsdr.cdc.gov detected in several brands of chewing was 3.54 µg/L. Water Systems (PWS) between 2001 and tobacco. Biomarkers 2005. EPA found that approximately Contact Information: ƒ Other chemicals, such as thiocyanate (in 160 (4.1%) of the PWSs that sampled and Division of Toxicology ƒ Urine is a convenient testing medium for cigarette smoke and food) and nitrate (in reported had at least 1 analytical detection and Environmental Medicine perchlorate. It might be detectable for only food) are known to inhibit iodide uptake. of perchlorate (in at least 1 entry/sampling Applied Toxicology Branch a few days after exposure because it leaves point) greater than or equal to the reporting Occupational Populations the body so rapidly. Because it is found in limit of 4 µg/L. These 160 are located in 1600 Clifton Road NE, F-32 food and may be present in drinking water, 26 States and 2 territories. ƒ Occupational exposure to perchlorates may Approximately Atlanta, GA 30333 detection would be more likely. 1.9% (or 637) of the 34,331 samples occur through the inhalation of dusts 1-800-CDCINFO collected (by these 3,865 PWSs) had formed during their manufacture and use. ƒ Levels of iodide in serum or urine, and 1-800-232-4636 levels of T3, T4, and TSH in serum, are not positive detections of perchlorate at levels ƒ Deposition of perchlorate dust into the ≥4 µg/L. The average concentration of www.atsdr.cdc.gov/toxpro2.html mouth is also possible. specific biomarkers of effect for perchlorate because other chemicals like perchlorate in those samples in which thiocyanate or nitrate also inhibit iodide perchlorate was detected was 9.85 µg/L uptake. and the median concentration was 6.40 µg/L (the average and median concentrations of perchlorate in all samples was <4 µg/L).

TM The ToxGuide is developed to be used as a pocket guide. Tear off at perforation and fold along lines. Chemical and Physical Information Routes of Exposure Relevance to Public Health (Health Effects)

Perchlorates are colorless salts ƒ Ingestion (drinking contaminated water, Health effects are determined hypothyroidism. The prevalence of eating contaminated food including milk). by the dose (how much), the hypothyroidism is about 5% in the general ƒ Five perchlorates are manufactured in large population of the United States, but there is amounts: magnesium perchlorate, ƒ Inhalation (breathing dusts or suspended duration (how long), and the no evidence that any of this percentage is potassium perchlorate, ammonium particles). route of exposure. due to perchlorate exposure. perchlorate, sodium perchlorate, and ƒ Dermal (contact with contaminated soil). lithium perchlorate. ƒ Because thyroid hormones play a critical Minimal Risk Levels (MRLs) role in the neurological development of the ƒ In water, perchlorate salts dissociate into a fetus, there is concern that hypothyroidism positively-charged cation and the Perchlorate in the Inhalation (maternal and fetal) during pregnancy could negatively-charged perchlorate anion. Environment ƒ No MRLs for inhalation exposure have result in neurodevelopmental effects. ƒ Perchlorates can be very reactive chemicals, ƒ Perchlorate has been found in food, been derived for perchlorate since adequate ƒ It is relevant to point out that other producing large amounts of heat capable of including cow’s milk, and in water. data were not available by this route of chemicals in the diet and in tobacco smoke exploding. exposure. ƒ Factories that make or use perchlorates may also can affect the thyroid gland in ways Oral ƒ Perchlorates are used in rocket motors, release them. similar to perchlorate. fireworks, road flares and explosives and ƒ ATSDR adopted the National Academy of ƒ Perchlorate entered the environment where are produced in the U.S., as well as Sciences chronic reference dose (RfD) of rockets were made, tested, and Children’s Health imported from other countries. 0.0007 mg/kg/day for the chronic oral MRL. disassembled and from fireworks, The MRL protects the most sensitive ƒ The most sensitive population is fetuses of ƒ Ammonium perchlorate is produced in explosives, flares, and similar products. population, the fetuses of pregnant women pregnant women who might have large amounts in the United States because Also, perchlorate is an impurity in certain who might have hypothyroidism or iodide hypothyroidism or iodide deficiency. it is used in solid rocket propellants. industrial and consumer products, such a deficiency, and also provides protection for ƒ Infants and developing children may be ƒ Perchlorate is used to prevent technetium cleansers and bleaches, which also may infants and developing children. uptake during medical imaging; it has also result in its discharge to the environment. more likely to be affected by perchlorate than adults because thyroid hormones are been used to counter the thyroid effects of ƒ Perchlorate also occurs naturally in the the drug amiodarone. Health Effects essential for normal growth and environment. development. ƒ Perchlorates can also form naturally in the ƒ Perchlorate released to the environment is ƒ The main target organ for perchlorate

atmosphere, leading to trace levels of deposited in soil or water (rivers, streams, toxicity in humans is the thyroid gland. perchlorate in precipitation. High levels of lakes, and ponds) and can leach into ƒ Perchlorate inhibits the thyroid’s uptake of Reference perchlorates occur naturally in some groundwater from soil. iodine. Iodine is required as a building Agency for Toxic Substances and Disease locations such as regions of west Texas and block for the synthesis of thyroid hormone. Registry (ATSDR). 2008. Toxicological northern Chile. ƒ Perchlorate has been found in a wide variety of foods including eggs, milk, ƒ Thyroid hormones regulate certain body Profile for Perchlorates. Atlanta, GA: U.S. ƒ Perchlorate has been detected as an vegetables, and fruits. functions after they are released into the Department of Health and Human Services, impurity in certain consumer products such blood. These include metabolism, growth Public Health Services. as bleach. ƒ Perchlorate will persist in water and soil for several years, but may eventually be and neurological development in children. degraded by microorganisms. Exposure of people to excessive amounts of perchlorate for a long time may lower the thyroid activity, leading to a condition called hypothyroidism. ƒ Perchlorate’s inhibition of iodide uptake by the thyroid must be great enough to cause