Chromium-6 in Drinking Water: Health Risks + Filtration Options

Walk into any health food store, and you’ll probably spot chromium on the shelves. Research suggests it supports healthy carb metabolism and fat utilization, and though I prefer to get this particular trace mineral from food, it serves a beneficial purpose.

So, when I first heard there might be chromium-6 in my water, I thought “Why would that be a bad thing?”

Turns out, chromium 6 is the highly toxic chemical that poisoned an entire town – the one featured in the movie about Erin Brockovich. So yeah, it’s definitely a bad thing, and the Environmental Working Group says that more than 2/3rds of all Americans (218 million people) are at serious risk of encountering it in their drinking water. (1)

So what exactly is chromium 6, how did it get into our water supply, and what can we do to minimize our exposure?

Let’s start with a quick chemistry cheat sheet

There are two main forms of chromium:

Trivalent chromium, also known as chromium 3, is a naturally occurring essential trace mineral that supports metabolism. Look for it in grass-fed beef, tomato juice, apples and green beans.
Hexavalent chromium, also known as chromium 6, is a highly toxic form that occurs naturally, but is mainly present in our environment due to industrial pollution. (2)

Health Effects of Chromium-6

After Erin Brockovich successfully won a $333 million class action lawsuit against Pacific Gas and Electric Company (PG&E) for exposing an entire town to chromium 6, something weird happened.

A Chinese scientist appeared to reverse his original finding that chromium-6 ingestion was strongly linked to stomach cancer – but that’s not what really happened.

Consultants hired by PG&E bought his data, did some “special math” to hide the causal link, then published the revised study without disclosing PG&E’s involvement. (1)

The revised study was eventually retracted, and the epidemiologist used the authentic study to guide public health goals for California. (3)

Based on that work and others, here’s what we know:

Chromium 6 is categorized as a Group 1 carcinogen according to the World Health Organization. Group 1 means it can cause cancer. Not “probably carcinogenic” (Group 2A) or “possibly carcinogenic” (Group 2B). Class 1 means “There is enough evidence to conclude that it can cause cancer in humans.” (4)
When inhaled or ingested, it can also cause liver damage, reproductive problems and developmental harm. (5)

Certain groups – such as children, people who take antacids and people with poor liver function – may be at higher risk. (6l)

Just One Drop

There is an old toxicology saying that says “The dose makes the poison.” Most things – even water – can be toxic if consumed in large enough quantities. But with chromium-6, the threshold is shockingly small.

After Erin Brockovich successfully proved that chromium 6 is toxic, the California Office of Environmental Health Hazard Assessment began the process of regulating it. They asked scientists to identify the maximum safe level, and after a thorough review set a public health goal of 0.02 parts per billion. (7) That’s not a typo. One part per billion is roughly equivalent to a single drop in an Olympic-sized swimming pool.

Unfortunately, industries that contribute heavily to the pollution and some water utilities that would be tasked with removing it pushed hard against setting exposure limits. So, in order to get any legislation passed, California legislators had to raise the maximum allowable limit to 10 parts per billion, which is 500 times the health goal set by the researchers. (8)

Why isn’t the EPA regulating chromium 6?

As of now, California is the only state with an enforceable drinking water standard specifically for chromium-6. There’s no federal limit, and no other state has stepped in with one of their own.

That might sound surprising, especially considering the health risks. But here’s the bigger picture: the EPA hasn’t added a single new contaminant to the Safe Drinking Water Act in nearly 20 years, despite a growing number of what they call “contaminants of emerging concern.”

Instead of regulating chromium-6 directly, the EPA only sets limits for total chromium – a number that lumps together both the beneficial form (chromium-3) and the toxic form (chromium-6), without distinguishing between them.

The current federal limit for total chromium is 100 parts per billion. For comparison, California’s public health goal for chromium-6 alone is just 0.02 parts per billion—a difference of nearly 5,000 times.

It’s not that chromium-6 can’t be removed on a large scale or that it’s health impacts are unknown. Through its Integrated Risk Information System (IRIS), the EPA classifies hexavalent chromium (Cr VI) as “likely to be carcinogenic via oral exposure.” (9)

It’s that it hasn’t been made a priority.

The EPA has followed a similar pattern with other contaminants—acknowledging the risks, but delaying or rolling back enforcement

Take PFAS, for example. In May 2025, the EPA announced that it’s rolling back key regulations on these so-called “forever chemicals” and delaying enforcement on others—even after previously declaring them toxic at “near zero” levels.

Why the shift? Most likely because setting legally enforceable limits would require water utilities to admit they can’t meet them – and upgrading infrastructure to meet those standards would be costly and complex.

How do I know if chromium 6 is in my water?

Chromium-6 is completely tasteless and odorless, making it impossible to detect without lab testing. The only reliable way to know if your water is affected is through advanced analysis at a certified water quality lab.

That’s likely part of the reason the issue remains hidden in plain sight – most people just have no practical way of knowing what’s in their tap.

To help bridge that gap, the Environmental Working Group created a national map based on available testing data. It shows which counties have detected chromium-6 in their water supply. You can search your zip code here to see if your area has reported contamination—just keep in mind, this map only reflects known results. An area not currently flagged could still be affected in the future.

With federal action moving slowly, local protections are inconsistent – and for now, the responsibility to reduce exposure to contaminants like chromium-6 falls to individuals and families. Fortunately, there are proven ways to do just that.

My #1 Filter Recommendation

After researching different water filters for over a year, Clearly Filtered won me over in every category – number of contaminants removed, independent testing, and price.

Their Water Pitcher is tested to remove >99.68% of Chromium 6 and their 3-Stage Under Sink System is tested to remove >99.67% of Chromium-6

Their water filters also remove up to 99.99% of 232+ tap water contaminants including:

❌ Fluoride
❌ Lead
❌ Chlorine
❌ PFAS “forever chemicals”
❌ Pesticides
❌ Herbicides
❌ Microplastics
❌ Phthalates
❌ Pharmaceuticals

. . . all while keeping beneficial minerals intact.

They say their products perform as well OR BETTER than reverse osmosis systems, and since big claims should come with verifiable information, they publish their performance data on each product page.

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