Perchlorate in Baby Formula Fact Sheet

Purpose

This fact sheet answers questions about CDC’s recent study of perchlorate in infant formula published in The Journal of Exposure Science and Environmental Epidemiology¹. It explains what the study looked at, what it found, and what CDC’s next steps will be. The fact sheet also reviews CDC’s established recommendation about how to best feed infants. This study does not change those existing recommendations.

Background

Perchlorate is a chemical that occurs naturally in the environment and is also used in explosives, fireworks, road flares, and rocket propellant. A combination of human activity and natural sources has led to the widespread presence of perchlorate in the environment.

Previous CDC studies have shown that nearly everyone in the U.S. is exposed regularly to low levels of perchlorate. People are exposed through eating food, and drinking milk and water that contain perchlorate. Trace levels of perchlorate have been found in both breast milk and infant formula.

High levels of perchlorate (thousands of times higher than the doses estimated to result from consumption of infant formula or breast milk) affects the thyroid gland by blocking its ability to use iodine. The thyroid gland needs iodine to make thyroid hormone. Thyroid hormone is important for proper development of fetuses and infants, and regulates how the body uses energy.

What did the study look at?

This study was intended to increase understanding of how infants may be exposed to perchlorate; it did not examine the potential health effects of perchlorate exposure.

CDC tested to see whether perchlorate could be measured in commercially available powdered infant formulas, including cow’s milk-based formulas with and without lactose, soy-based formulas, and elemental formulas, which are typically made with synthetic amino acids.

CDC researchers then used those findings, along with estimates of baby weight at different ages and estimates of the amount of formula typically consumed, to determine several hypothetical exposure situations involving formula mixed with drinking water containing perchlorate.

Finally, for each hypothetical situation CDC calculated how much perchlorate would need to be in water to cause the mixed formula to exceed the U. S. Environmental Protection Agency’s reference dose, a level set to estimate the daily exposure levels over a lifetime that would cause no ill effects. It is not known whether exceeding the reference dose might have ill effects.

What did the study find?

All of the powdered infant formulas tested contained perchlorate. Cow’s milk-based formula with lactose had a significantly higher concentration of perchlorate than the other types.

The hypothetical dosing situations showed that for most infants the amount of perchlorate in the formula product itself would not result in exposures higher than the U. S. Environmental Protection Agency's reference dose. The actual dose would depend on the baby's weight, the amount of formula consumed, the type of formula, the amount of perchlorate in other foods consumed by the infant, and the amount of perchlorate in the water mixed with the formula.

Most foods used for infant feeding are likely to contain trace amounts of perchlorate at levels below those shown to be harmful. This small study assessed whether perchlorate could be measured in a diverse set of formula products, and it adds to our knowledge of how infants could be exposed to perchlorate. However, because it tested small numbers of samples and made use of hypothetical exposure scenarios, the findings cannot be generalized to entire brands or types of formula. The study also did not assess potential health effects of exposure. For all of these reasons, this study does not change CDC’s existing recommendations for infant feeding.

• Table of Perchlorate Levels in Powdered Infant Formula [PDF - 93 KB]

Does this study have limitations?

Many foods used for infant feeding are likely to contain trace amounts of perchlorate, at levels below those shown to be harmful. This small study assessed whether perchlorate could be measured in a diverse set of formula products and adds to our knowledge of how infants could be exposed to perchlorate. However, because it tested small numbers of samples and made use of generally conservative hypothetical exposure scenarios, the findings cannot be generalized to entire brands or types of formula. The study also did not assess potential health effects of exposure. For all of these reasons, this study does not change CDC’s existing recommendations for infant feeding.

What other studies might be needed?

The study identifies a potential source of exposure of infants to perchlorate and raises questions of how much perchlorate might be absorbed by infants drinking formula. CDC will next undertake research to help answer that question by measuring the levels of perchlorate in infants’ urine.

Once we understand how much perchlorate is absorbed into infants’ bodies, future studies can explore the potential health effects of exposure to low levels of perchlorate over time.

What are CDC’s recommendations for feeding infants?

CDC continues to recommend breastfeeding as optimal for both mothers and babies. Breastfed babies have a lower risk of infections and various chronic diseases. Mothers who breastfeed have a lower risk of breast cancer, ovarian cancer and type II diabetes

Parents who do use infant formula should be aware that the U. S. Food and Drug Administration requires that all baby formulas include iodine, which may offset any potential effects of perchlorate in the formula.

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