What Is Formaldehyde?

In plain English: Formaldehyde is a colorless, strong-smelling gas used as a preservative and disinfectant, and released by certain preservatives in cleaning and personal care products. The International Agency for Research on Cancer classifies it as a Group 1 human carcinogen.

Also listed as: formaldehyde, methanal, formalin, CH2O, CAS 50-00-0

The honest science

In short: formaldehyde is classified as a Group 1 human carcinogen, and it most often enters cleaning products indirectly through formaldehyde-releasing preservatives like DMDM hydantoin and quaternium-15 rather than as a listed ingredient itself. 12 Our full guide below covers the releaser names to watch for and how to spot them on a label in plain-English detail.

Where you'll find it

  • disinfectants
  • all-purpose cleaners
  • products with formaldehyde-releasing preservatives
  • cosmetics
  • indoor air from many household sources

The safer-swap angle: Cutting avoidable indoor formaldehyde sources is a reasonable, low-effort win. Ecolosophy's small-batch, plant-based concentrate is made with care and uses no formaldehyde or formaldehyde-releasing preservatives.

→ Read the full deep-dive guide on Formaldehyde

Frequently asked questions

Is formaldehyde really a carcinogen?

Yes. IARC classifies it as a Group 1 human carcinogen, based mainly on inhalation exposure evidence. The concern is greatest for sustained airborne exposure rather than brief trace contact.

How does formaldehyde get into cleaning products?

Sometimes directly as a disinfectant or preservative, and often indirectly through formaldehyde-releasing preservatives such as DMDM hydantoin and quaternium-15 that give it off slowly.

How can I lower my exposure?

Ventilate while cleaning, and choose products free of formaldehyde and formaldehyde releasers. Reducing avoidable household sources helps lower overall indoor air exposure.

Sources

  1. Cancer effects of formaldehyde: a proposal for an indoor air guideline value — PMC / NCBI
  2. Formaldehyde 50-00-0 Hazard Summary — US EPA

Ingredient safety data changes as new research is published, and product formulas change over time. Always read the current label and check primary sources.

Related terms

← Back to the full ingredients glossary

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