What to Know About Perchlorate and Your Health

Medically Reviewed by Brunilda Nazario, MD on April 04, 2022
4 min read

Perchlorate is a chemical that’s used in things like rocket fuel, explosives, road flares, and fireworks. Small amounts of it can also form naturally in dry states in the Southwest. It has no color or odor.

Perchlorate shows up in some public drinking water systems and in certain foods. This concerns some people and public health experts, because taking in high amounts of the chemical might throw your thyroid gland out of whack. Perchlorate may also be linked to brain-related problems in fetuses and babies.

Research shows that it’s common to get exposed to low levels of this chemical in the U.S. Here are answers to questions you might have.

The U.S. Environmental Protection Agency (EPA) says perchlorate doesn’t show up often enough and at levels of concern in tap water, so it hasn’t set a limit on the chemical. Some environmental and health experts and groups question or dispute that conclusion, though.

States can set their own standards about perchlorate in drinking water, and the EPA says its decision won’t affect those.

Scientists often spot perchlorate in water supplies that are close to places where companies make or use solid rocket fuel. But sometimes experts can’t find an obvious source of the chemical.

You may be able to find out if perchlorate is in your drinking water by talking to your water supplier. (If you don’t know who it is, you might find the info on your water bill.) You can also ask whether they’re taking any steps to limit your exposure to it.

If you get your drinking water from a private well, the EPA recommends you get the water tested for perchlorate by an approved lab.

If you’re concerned about the amount of perchlorate in your tap water, you could consider using bottled water.

You can’t remove the chemical by heating or boiling your water. But the EPA says you could get rid of it with a water filter system called a point-of-use reverse osmosis device. You connect this device to a single fixture (like under your kitchen sink), and it gets rid of contaminants from the water that goes to that fixture.

It can happen in few different ways:

Food. Scientists have found perchlorate in items like milk and leafy greens. That doesn’t mean you should avoid these foods.

Where you live. You’re more likely to be exposed to the chemical if you live close to:

  • A factory that makes fireworks, flares, or other explosive devices
  • A waste site or rocket-making or -testing facility that has high levels of perchlorate in the soil or groundwater

If you live in an area like this and you have children, don’t let them play in the dirt or eat dirt. And make sure they wash their hands a lot, especially before they eat.

Some other things that could expose you to perchlorate are:

  • Chewing tobacco
  • Fireworks shows
  • Using certain cleaning products and pool chemicals

High levels of perchlorate can affect your thyroid, a butterfly-shaped gland in your neck that makes important hormones. Thyroid hormones control things like how quickly you burn calories and how fast your heart beats. In babies, those hormones are very important for brain development – and they influence how well your brain works throughout your life.

Your thyroid needs iodine, a mineral found in some foods, to make hormones. But perchlorate gets in the way of your thyroid’s ability to absorb iodine.

Being exposed to higher levels of perchlorate for a long time may bring on a condition called underactive thyroid (or hypothyroidism), where your thyroid doesn’t make enough hormones. Without treatment, hypothyroidism can lead to heart issues, mental health conditions like depression, birth defects, and many other problems.

Perchlorates are more likely to affect babies and young children, compared to adults, since thyroid hormones are crucial for healthy growth and development.

The risk may be highest if you’re pregnant and you have hypothyroidism or you’re low on iodine. Your baby needs enough thyroid hormones in the womb for its central nervous system to develop right during the first and second trimesters. A low-producing thyroid in a pregnant or breastfeeding person (due to not getting enough iodine) has been linked to development delays and less learning ability in their babies and children.

If you’re pregnant or breastfeeding, work with your doctor to make sure you’re getting enough iodine. Breast milk and infant formulas are good ways for nursing babies to get iodine. Talk to your doctor before you or your infant tries any new supplement, so they can make sure it’s safe.

Otherwise, the FDA says most people in the U.S. get enough iodine from their diets and don’t need to take supplements to protect themselves from perchlorate in water and foods. Talk to your doctor if you’re concerned that you’re not getting enough iodine.

Even though the EPA has decided not to regulate the levels of perchlorate in drinking water for now, the agency says it will keep considering new information about the health effects of perchlorate.

The EPA says it’s also taking other steps, like:

  • Cleaning up existing sites contaminated with perchlorate
  • Possibly revising standards for the open burning and open detonation of waste explosives and bulk propellants, which are linked to perchlorate contamination
  • Improving labeling requirements for hypochlorite solutions (which are used to disinfect drinking water). The EPA says it’s possible for perchlorate to form while these solutions are stored if people storing and handling the solutions don’t follow best practices.
  • Giving water systems resources and recommendations to lower perchlorate in drinking water
  • Doing more research on perchlorate in open waters like rivers, lakes, and streams
  • Creating an online information “toolkit” about perchlorate that’s meant to help drinking water systems and communities concerned about their tap water