Chromium 6 in tap water

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States Affected
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People Affected
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Toxicity Rating
Health Effects

Cancer, liver damage, reproductive problems, developmental harm

The legal limit is
Health Guideline
< 10 ppb
what is considered unhealthy
Legal Limit
What is chromium 6?
Chromium-6, also known as hexavalent chromium, is a heavy metal categorized as a Group 1 carcinogen by the World Health Organization. Group 1 is their highest and most serious classification. Chromium-6 is a by-product of industrial manufacturing and is known to cause cancer in extremely small amounts. Especially high levels of chromium-6 result from manufacturing done in steel and pulp mills and the leather tanning process. If you’ve ever seen the movie Erin Brokovich, then you’ve heard of chromium-6. This movie documented the poisoning of Hinkley, California, with this toxic substance and the ensuing legal battle and settlement.
Why is chromium 6 in my tap water?
This highly dangerous, cancer-causing tap water contaminant enters drinking water through runoff from industrial plants. Harmful levels of chromium-6 have been found in tap water in all 50 states, affecting 2/3 of all Americans. It should be noted that while chromium-6 is so widespread and so dangerous, it can’t be seen, smelled, or tasted. Even though chromium-6 contamination is a nationwide problem, it is not specifically regulated by the United States Environmental Protection Agency (EPA). Instead, they regulate total chromium, which includes chromium-6 and the much less toxic chromium-3 (chromium-3 is actually an essential element for humans).1 The U.S. EPA limit for total chromium is 5,000 times the level of chromium-6 considered to be safe by the California EPA.2
Why is chromium 6 in my tap water harmful?
Scientific research from a 2-year study done by the National Toxicology Program found that drinking water with chromium-6 definitively caused cancer in test subjects. So far, California is the only state to have a public health goal and an enforceable legal limit on this highly toxic carcinogen. However, this limit is still 500 times higher than what scientific investigators have declared as an ideal public health goal.
How much chromium 6 is safe?
The safe answer is none, although the exact amount is unknown. Scientists in California have suggested that more than 0.02 ppb can potentially cause cancer.2 For reference of just how little an amount that is, 1 part per billion is 1 drop in an Olympic-sized swimming pool. If that single drop was divided into 100 parts, 2 of those parts would equal 0.02 ppb.
What can I do about chromium 6 in my tap water?
Removing chromium-6 from tap water requires sophisticated filtration technology. Clearly Filtered® with Affinity® Filtration Technology gives you the power to remove up to 99.4% of chromium-6, giving you peace of mind that comes from knowing your tap water is finally clean and safe. Standard water filters that rely on simple carbon (like Brita®) or charcoal are only effective at removing unpleasant odors and taste. These filters are not capable of stopping complex heavy metals like chromium-6 and instead allow them to pass right through the filter into the water you're drinking.
How does Clearly Filtered do at Removing Chromium 6 in tap water?
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Chromium 6 in tap water Removal

1. US EPA. National primary Drinking Water Regulations. Accessed August 27, 2019.

2. California Office of Environmental Health Hazard Assessment. Final Public Health Goal for Hexavalent Chromium. July 2011. Accessed August 27, 2019.

3. Stout MD, Herbert RA, Kissling GE, et al. Hexavalent chromium is carcinogenic to F344/N rats and B6C3F1 mice after chronic oral exposure. Environ Health Perspect. 2009;117(5):716-722. doi:10.1289/ehp.0800208