Smarter Living: Chemical Index

Perchlorate is a hormone-disrupting chemical used in rocket fuel. It contaminates the drinking water of more than 20 million Americans.

Health Concerns

Perchlorate interferes with the uptake of iodine into the thyroid gland, which can decrease the production of thyroid hormone. Thyroid hormone is essential for normal brain development. Even subtle changes of thyroid hormone levels during pregnancy have been associated with decreased intellectual and learning capacity in childhood.


Perchlorate is used in rocket fuel as well as fireworks, ammunition and explosives. It contaminates the drinking water of more than 20 million Americans.

A study published in 2009 reported elevated perchlorate levels in powdered infant formula. Infants given formula reconstituted with perchlorate-contaminated drinking water would be consuming unsafe amounts of the chemical, according to EPA standards.

Stay Safe

Check your annual drinking water report to find out if perchlorate contamination is a concern in your area.

If your water system has a problem with perchlorate, use a reverse osmosis water treatment system certified by NSF International. Don't rely on bottled water--it's not necessarily any safer than tap water.

Take Action

Consumers can do only so much to protect themselves from harmful exposures to unsafe chemicals like perchlorate. Congress must act to reform the Toxic Substances Control Act and require the chemical industry to substantially reduce people's exposure to such chemicals of concern. Contact your Congressperson and get them to support reform of the Toxic Substances Control Act in order to keep the public safe.

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NRDC Protecting People from Unsafe Chemicals

Haddow JE, et al. Maternal thyroid deficiency during pregnancy and subsequent neuropsychological development of the child. New Eng J Med 341:549-555, 1999.

Pop VJ, et al. Low maternal free thyroxine concentrations during early pregnancy are associated with impaired psychomotor development in early infancy. Clin Endocrinol. 50:149-155, 1999.

Schier JG et al. Perchlorate exposure from infant formula and comparisons with the perchlorate reference dose. Journal of Exposure Science and Environmental Epidemiology advance online publication 18 March 2009.

last revised 12/27/2011

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