ToxicFree FoundationNonprofit · Ingredient research Apply for certification
CosmeticsPersonal Care ProductsGovernment Regulation

Formaldehyde releasers: the hidden preservatives Washington will restrict in 2027

ToxicFree Foundation

Formaldehyde rarely shows up by name on a shampoo or lotion label. Some products instead contain preservatives that slowly release small amounts of formaldehyde into the formula over time. These ingredients are known as formaldehyde releasers, and they are now drawing attention from regulators. Washington State will restrict 25 of them in cosmetics starting January 1, 2027, the broadest state restriction on this group so far.

What formaldehyde releasers are

Water-based products such as shampoo, body wash, lotion and liquid soap can grow bacteria and mold, so they need preservatives. Formaldehyde releasers do that job by breaking down and giving off formaldehyde, which kills microbes. Because the formaldehyde is created inside the product, it is not listed as a separate ingredient.

Formaldehyde itself is a well-studied chemical. The National Toxicology Program named it "a known human carcinogen" in its 12th Report on Carcinogens, and the International Agency for Research on Cancer also classifies it as a human carcinogen. Washington's Department of Ecology summarizes the concern this way: "Formaldehyde can cause cancer, respiratory problems such as asthma, allergic skin responses, and irritation of and damage to eyes and skin."

Names to look for on a label

These are some of the formaldehyde releasers on Washington's list that you are most likely to see on personal care labels:

  • DMDM Hydantoin
  • Diazolidinyl Urea
  • Imidazolidinyl Urea
  • Quaternium-15
  • Sodium Hydroxymethylglycinate
  • 2-Bromo-2-Nitropropane-1,3-Diol (Bronopol)
  • 5-Bromo-5-Nitro-1,3-Dioxane (Bronidox)
  • Tosylamide/Formaldehyde Resin

For hair smoothing and straightening treatments, the FDA advises checking labels for "Formaldehyde, Formalin, Methylene glycol." These products can release formaldehyde into the air when heated during styling.

What the rules say

  • Washington: Under the Toxic-Free Cosmetics Act, the Department of Ecology adopted a rule on August 28, 2025, that restricts 25 named formaldehyde releasers when they are intentionally added to cosmetics. The restriction takes effect January 1, 2027. Retailers may sell existing stock through the end of 2027. Formaldehyde itself has been banned as an intentionally added cosmetic ingredient in the state since January 1, 2025.
  • California: Since January 1, 2025, the state has banned cosmetics with intentionally added formaldehyde, paraformaldehyde, methylene glycol and quaternium-15.
  • European Union: Cosmetics containing formaldehyde releasers must carry the warning "releases formaldehyde" when the total formaldehyde released reaches 0.001% (10 ppm). Since July 31, 2026, every such product on the EU market must carry the warning.

Most of the U.S. still has no restriction on these ingredients, so products sold in other states may contain them.

Practical tips

  • Check the ingredient list on shampoo, conditioner, body wash, baby wash, lotion and liquid hand soap. Water-based products like these need preservatives.
  • If you have a formaldehyde allergy or frequent skin irritation, ask your dermatologist whether to avoid formaldehyde releasers as well.
  • Before a salon smoothing or keratin treatment, ask the stylist whether the product contains formaldehyde, formalin or methylene glycol, and make sure the room is well ventilated.
  • Look for products that use other preservative systems. A preservative-free water-based product is not automatically safer, because contamination is a real risk.

Read more in our ingredient profiles for Formaldehyde, DMDM Hydantoin, Diazolidinyl Urea and Bronopol, or paste a product's ingredient list into our label checker to see how each ingredient is rated.

Sources

Check the ingredients in your products.

Search the ToxicFree Foundation’s safety ratings for ingredients in cosmetics, personal care, household cleaning products, and more.

Search the database
Keep reading

More on Cosmetics.

All articles
Food AdditivesCalifornia will track and publish where “forever chemical” pesticides are sprayedCalifornia will soon start telling the public where "forever chemical" pesticides are being sprayed. On September 27, 2026, Governor Gavin Newsom signed AB…CosmeticsHow to read a cosmetics ingredient labelThe front of a bottle is marketing. The back is where the facts are. Every cosmetic sold in stores in the U.S. has to list its ingredients, and once you know a few…Cosmetics“Forever chemicals” are now banned from cosmetics in seven states. Here’s what the FDA found.If you live in one of seven states, the makeup and skin care on store shelves can no longer contain intentionally added PFAS, the family of chemicals known as…CosmeticsA popular skincare product is part of nationwide FDA recall.First Aid Beauty has issued a recall for more than 2,700 jars of Ultra Repair Cream. It's sold across the country on the First Aid Beauty site and major retailers…