Cancer prevention: Top 5 cancer-causing chemicals to avoid for cancer prevention


  • Toxic chemicals in the environment are a major contributor to cancer risk.
  • There is no risk-free level of exposure to cancer-causing chemicals – the lower the better.
  • Find out more about EWG’s top 5 recommendations for cancer prevention.


Cancer-causing chemicals can lurk in almost any everyday product you can imagine: candy, toys, clothes, hair dyes, pet food and more. Reducing your exposure to items that have potentially harmful ingredients is a great way to safeguard your health.

Cancer is a problem that affects all communities, some disproportionately more than others.  It’s the federal government’s responsibility to protect us from toxic chemicals by regulating or banning them. But that oversight continues to fall short, so for now, we have to study ingredient labels and choose cleaner, healthier options.

EWG's Top 5 Chemicals to Avoid for Cancer Prevention

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5 contributors to cancer risk

This can seem a daunting task when you’re shopping. So EWG is offering a list of what we consider the five worst cancer-causing chemicals in our daily lives to avoid.

1. Toxic “forever chemicals” in consumer products

The highly toxic “forever chemicals” known as PFAS can be found in a vast array of consumer products and industrial applications. Even very low doses of PFAS in drinking water have been linked to increased risk of testicular and kidney cancer, in addition to other health harms

PFAS are among the most persistent compounds in existence, contaminating everything from drinking water to food, food packaging and personal care products – even pet food. They’re known as forever chemicals because they don’t break down in the environment.

What you can do

States are beginning to ban or regulate PFAS, and federal authorities like the Environmental Protection Agency are also taking steps to turn off the tap of PFAS. 

Until more comprehensive regulations are in place to tackle PFAS, try to avoid anything stain-, wrinkle- or water-resistant, such as nonstick pans, stain-resistant upholstery, spill-proof children’s products and toys, rainproof outerwear and waterproof and long-lasting cosmetics. Check out EWG’s Guide To Avoiding PFAS Chemicals for more tips.

2. Contaminants in your tap water

What’s in your drinking water? EWG’s Tap Water database highlights how drinking water quality varies widely across the U.S. Yours might be contaminated with one or more chemicals linked to cancer:

  • Nitrate, a fertilizer chemical from agricultural and urban runoff.
  • Arsenic, a naturally occurring element in the earth but also from mining and burning of fossil fuels that contaminate groundwater.
  • PFAS, which may contaminate drinking water for over 200 million people in the U.S.
  • Industrial solvents, which may end up in drinking water supplies from nearby contaminated sites.
  • Radiation, elements from natural deposits found in higher concentration as a result of mining, drilling and processing certain elements, such as uranium.

What you can do

Although bottled water is sometimes used to replace tap drinking water in contaminated communities, it’s not a sustainable long-term solution. Buying a home water filter is the most economical and reliable option for improving water quality at home. EWG’s water filter guide can help everyone find the right filter for their budget.

If you’re among the 44 million Americans – about one in seven – who rely on private well water, you’re mostly on your own when it comes to your tap water’s quality. Get it tested annually and other certain other circumstances to find out whether it’s contaminated. The Centers for Disease Control and Prevention recommends “point of use” water treatment options that work on individual faucets or spigots.

3. Artificial food colors

Two in five food products contain artificial coloring chemicals that can possibly harm your health, research has found. A commonly used food dye, Red 3, has been linked to cancer and is not allowed in personal care products in the U.S. But Red 3 and other artificial food colors are allowed in thousands of foods marketed to kids, including some types of popcorn, hot chocolate mix, candy, snack mix, plus many strawberry- or cherry-flavored foods.

One of these chemicals, titanium dioxide, makes foods a brighter white, and it may also increase the risk of cancer. It’s found in popular candy, as well as coffee creamer, sauces and dressings.

What you can do

Foods containing artificial colorants may be more widely accessible, but they’re usually less nutritious, so avoiding them – or eating less of them – is a good start. Study labels and stay away from ingredients with names like Red 3 and Blue 1. These chemicals might also appear with “Lake” in their name, such as Lake Allura Red. 

EWG's Food Scores database rates more than 80,000 foods in a simple, searchable online format, helping shoppers find products without these potentially unsafe ingredients. 

4. Pesticides in produce

Lowering exposures to pesticides from produce also reduces a person’s mortality risk from cardiovascular disease, cancer and respiratory diseases, according to research published by scientists from the Harvard T.H. Chan School of Public Health.

A diet that includes fruits and vegetables is essential for health and lowering your cancer risk. But nearly three-quarters of produce sold in the U.S. contains residue of potentially harmful pesticides, according to EWG’s Shopper’s Guide to Pesticides in Produce™. That doesn’t include pesticides found on other food, such as oats, rice, wheat and beans

What you can do

Choose organic fruit and vegetables, whenever possible. Consult EWG’s Dirty Dozen™ list of fruits and vegetables that have the highest traces of pesticides, and try to buy organic when possible to lower the risk of exposure to these chemicals. Our Clean Fifteen™ list reveals the items with the least pesticide residue, and they’re OK to buy non-organic, if necessary.

5. Hair colorants and relaxers 

Many studies point to a connection between hair treatments and cancer, particularly hair colorants and relaxers. Some ingredients that have been or still are used in hair dyes are considered “reasonably anticipated to be human carcinogens,” according to the National Toxicology Program. 

Research shows workplace exposure to hair dye probably causes cancer in humans. Other studies have found associations between breast cancer and the use of hair dye and hair smoothing treatments. And longer duration and earlier use of hair straighteners, as well as combining permanent hair dye and relaxers, are associated with breast tumor features that indicate a higher risk. 

What you can do

The American Cancer Society says most of the concern about cancer risk has been about semi-permanent and permanent dyes, as well as darker hair dyes in general, because those have more of the ingredients that may cause cancer. More research is needed, but avoiding hair dyes and relaxers is a great step for cancer prevention. 

EWG’s Skin Deep® database rates more than 80,000 personal care products in a simple, searchable online format, helping you find products without potentially unsafe ingredients.

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