What Is Formaldehyde?

What Is Formaldehyde?

This is part of our ongoing series helping consumers better understand chemicals, chemistry, and product formulations. We translate the science, bust the myths, and give you an honest assessment, so you can make informed choices for your family!



What it is:

Formaldehyde is a volatile organic compound that’s colorless, flammable, extremely noxious, and toxic (1).

What it does:

Formaldehyde was first discovered in 1859 and its versatility has made it a much more common chemical ingredient since then (2). It’s used to make many types of plastics, pesticides and industrial disinfectants; to tan leather; to make resins and adhesives used in carpets and plywoods; as a textile finisher to prevent creasing; as a tissue preservative in medical labs; and as an embalming fluid in mortuaries (3). It’s also used as a preservative in some ingredients used for the manufacture of, cosmetic and personal care products, as well as household cleaners (3). Formaldehyde is all around us, every day.

Why we’re featuring it today:

Formaldehyde is included in our Honestly Free Guarantee because it poses serious risks to human health. Here’s just a small snapshot of what we know:

  • Formaldehyde is listed as a known human carcinogen in the Thirteenth Report on Carcinogens published by the National Toxicology Program because it causes cancer of the throat, nose, and blood (leukemia).
  • Formaldehyde is a well-established neurotoxin that can cause headaches, dizziness, and sleep disorders and it affects memory, learning, and behavior (4,5,6).
  • Exposure to low levels of formaldehyde (levels common in the indoor air of new buildings and homes) can irritate and burn the eyes, nose, throat, and skin (7).
  • In women, exposure can cause reproductive issues like menstrual disorders and spontaneous abortion, as well as developmental impacts to fetuses such as chromosome and DNA damage (8,9,10).
  • People with asthma may be more sensitive to exposure to formaldehyde and studies show that exposure to formaldehyde increases the development of childhood asthma (9,11,12).
  • Skin allergies and skin sensitization following dermal exposure to formaldehyde is also well documented (9,13).

Need we say more?

Want your home to be Honestly Free of formaldehyde?

Given its widespread use, it’s highly unlikely your home will ever be totally Honestly Free of formaldehyde, but there are a few things you can do to significantly reduce your exposure.

  • Clean up indoor air. Our primary exposure to formaldehyde comes from breathing it in. You can clean up your indoor air by:
    • Choosing solid wood furnishings and avoiding pressed woods, plywoods, and particle board. Before purchasing building materials, cabinetry, and furnishings, ask the manufacturer about possible formaldehyde content.
    • Using zero-VOC paints and varnishes. There are even some paints that will block formaldehyde from off-gassing out of pressed woods and other paints that actually absorb formaldehyde – essentially turning your walls into giant air filters!
    • Cleaning chimneys and wood-burning appliances. Smoke from combustion contains formaldehyde, so prevent it from entering your home by properly maintaining anything that creates it.
    • Keeping exhaust out. Gas burning engines in cars, mowers, leaf blowers, and other equipment release exhaust that contains formaldehyde (and other risky pollutants). If you have an attached garage, make sure the door to your home is effectively sealed and use a vapor barrier on any shared walls. Also, don’t idle them outside open windows.
    • Using safe household cleaners. Since cleaning products aren’t required to have detailed ingredients lists, avoid any products that aren’t transparent about what’s inside.
    • Opening windows. It couldn’t be easier – even just a few minutes a day lets the bad air out and better air in!
  • Choose safe personal care products. Formaldehyde can be found on the ingredients labels of things like nail polish and hair straightening formulas, but other products such as baby shampoo, body wash, and soap may contain it even though you might not see it listed as an ingredient. That’s because some products contain formaldehyde-releasing preservatives (FRPs) that – as the name implies – release small amounts of formaldehyde over time. Read labels and avoid products containing the following ingredients: Formaldehyde, quaternium-15, dimethyl-dimethyl (DMDM) hydantoin, imidazolidinyl urea, diazolidinyl urea, sodium hydroxymethylglycinate, 2-bromo-2-nitropropane-1,3-diol (bromopol).


  1. Tox Town - Formaldehyde - Toxic chemicals and environmental health risks where you live and work - Text Version. Retrieved October 5, 2015, from http://toxtown.nlm.nih.gov/text_version/chemicals.php?id=14
  2. Fox, C. H., Johnson, F. B., Whiting, J., & Roller, P. P. (1985). Formaldehyde fixation. J histochem Cytochem, 33(8), 845-853.
  3. EPA. Retrieved October 5, 2015, from http://www2.epa.gov/formaldehyde/facts-about-formaldehyde
  4. Tulpule, K., & Dringen, R. (2013). Formaldehyde in brain: an overlooked player in neurodegeneration?. Journal of neurochemistry, 127(1), 7-21.
  5. Songur, A., Ozen, O. A., & Sarsilmaz, M. (2010). The toxic effects of formaldehyde on the nervous system. In Reviews of environmental contamination and toxicology (pp. 105-118). Springer New York.
  6. Kilburn, K. H., Warshaw, R., & Thornton, J. C. (1987). Formaldehyde impairs memory, equilibrium, and dexterity in histology technicians: effects which persist for days after exposure. Archives of Environmental Health: An International Journal, 42(2), 117-120.
  7. Formaldehyde and Cancer Risk. Retrieved October 5, 2015, from http://www.cancer.gov/about-cancer/causes-prevention/risk/substances/formaldehyde/formaldehyde-fact-sheet
  8. Duong, A., Steinmaus, C., McHale, C. M., Vaughan, C. P., & Zhang, L. (2011). Reproductive and developmental toxicity of formaldehyde: a systematic review.Mutation Research/Reviews in Mutation Research, 728(3), 118-138.
  9. Kim, K. H., Jahan, S. A., & Lee, J. T. (2011). Exposure to formaldehyde and its potential human health hazards. Journal of Environmental Science and Health, Part C, 29(4), 277-299.
  10. Thrasher, J. D., & Kilburn, K. H. (2001). Embryo toxicity and teratogenicity of formaldehyde. Archives of Environmental Health: An International Journal,56(4), 300-311.
  11. Krzyzanowski, M., Quackenboss, J. J., & Lebowitz, M. D. (1990). Chronic respiratory effects of indoor formaldehyde exposure. Environmental research,52(2), 117-125.
  12. McGwin Jr, G., Lienert, J., & Kennedy Jr, J. I. (2010). Formaldehyde exposure and asthma in children: a systematic review. Environmental health perspectives (Online), 118(3), 313.
  13. NIOSH Skin Notation Profiles: Formaldehyde/Formalin. Washington, DC: United States Government. Retrieved October 5, 2015, from http://www.cdc.gov/niosh/docs/2011-145/pdfs/2011-145.pdf
  14. Broder, I., Corey, P., Brasher, P., Lipa, M., & Cole, P. (1991). Formaldehyde exposure and health status in households. Environmental health perspectives,95, 101.
  15. Formaldehyde and Cancer Risk. (n.d.). Retrieved January 05, 2015, from http://www.cancer.gov/cancertopics/factsheet/Risk/formaldehyde
  16. Swenberg, J. A., Moeller, B. C., Lu, K., Rager, J. E., Fry, R. C., & Starr, T. B. (2012). Formaldehyde Carcinogenicity Research 30 Years and Counting for Mode of Action, Epidemiology, and Cancer Risk Assessment. Toxicologic pathology, 0192623312466459.

This post was revised as of 10/7/2015. 

We aim to provide you with the most honest and credible information possible. This article was reviewed for accuracy by The Honest Team and was written based on trusted sources that are linked at the bottom of the article.