Perchlorate in tap water

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States Affected
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People Affected
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Toxicity Rating
Health Effects

Hormone disruption, harm to fetal growth and child development 

The legal limit is
Health Guideline
1 ppb
what is considered unhealthy
Legal Limit
What is perchlorate?
Perchlorate is a naturally occurring and man-made chemical used in rocket fuel, flares, fireworks, and explosives. This hazardous chemical is also found in bleach and fertilizer, as well as a variety of foods including certain fruits, vegetables, grains, and whole milk.
Why is perchlorate in my tap water?
Perchlorate easily dissolves into water and typically sneaks into public water supplies through soil, groundwater, and irrigation water. It has been found in drinking water in at least 26 states.
Why is perchlorate in my tap water harmful?
Perchlorate can block your thyroid from taking in iodide, which can lead to hypothyroidism. This iodide deficiency can impact brain development in fetuses and infants by interfering with the thyroid’s ability to produce hormones responsible for growth and development.
Can perchlorate cause Hypothyroidism?
Yes. Hypothyroidism occurs when an underactive thyroid does not produce enough thyroid hormones. Remember, the thyroid is powered by iodide, and perchlorate can prevent your thyroid from taking in the iodide it needs to produce hormones.
How much perchlorate is safe?
There is no national regulation on perchlorate in public drinking water systems, as the U.S. Environmental Protection Agency (EPA) claims not enough people are exposed to unsafe levels of the chemical to warrant regulation. However, several states have spoken out against this, and California and Massachusetts have both set their own enforceable standards and guidelines at the state level.
In 2020, the National Resources Defense Council (NRDC) filed suit against the EPA after the organization refused to set a nationwide standard for perchlorate in public drinking water supplies. In the suit, the NRDC stated that more than 16 million people may be affected by perchlorate in their drinking water.
Is perchlorate in bottled water?
Probably. However, since the EPA does not regulate perchlorate in tap water, the FDA is not required to regulate perchlorate in bottled water.
What can I do about perchlorate in my tap water?
Clearly Filtered’s Water Pitcher with Affinity® Filtration Technology removes up to 96.0% of perchlorate from your tap water. Upgrade to our superior water filters so you never have to worry about perchlorate lurking in your water again. Remember, typical carbon or charcoal filters do not remove perchlorate. Nor does boiling water.
How does Clearly Filtered do at Removing Perchlorate in tap water?
Clearly Filtered with
Affinity Filtration Technology Product
Water Pitcher Filter
Under-the-Sink FIlter
Water Bottle Filter
Refrigerator Filter
Perchlorate in tap water Removal

1. U.S. EPA. Perchlorate In Drinking Water Frequent Questions. Accessed April 1, 2021.

2. U.S. FDA. Exploratory Survey Data on Perchlorate in Food 2004-2005. Accessed April 1, 2021.

3. U.S. FDA. Perchlorate Questions and Answers. Accessed April 1, 2021.

4. John Hopkins Medicine. Environmental Pollutant May Be More Hazardous Than Previously Thought. Accessed April 1, 2021.

5. NRDC. NRDC Sues to Protect Kids from Perchlorate in Tap Water. Accessed April 1, 2021.

6. Newsweek via MSN. EPA Sued For Not Regulating Rocket Fuel Chemical in Drinking Water. Accessed April 1, 2021.