Formaldehyde
The simplest aldehyde. Historically used as a preservative in shampoos, nail polishes, and keratin straighteners. IARC Group 1 carcinogen (in industry workers). Banned as a standalone preservative in the EU under Regulation 1223/2009 since 2019. Only formaldehyde-releasing preservatives (DMDM Hydantoin, Imidazolidinyl Urea) are permitted, and only with mandatory 'contains formaldehyde' labelling when concentration exceeds 0.05%.
Evidence by route
Topical application
FNo evidence or proven inefficacy for this route of administration.
IARC Group 1 carcinogen for occupational exposure. Contact allergen. Inhalation causes mucosal irritation and asthma. Use in cosmetics is banned or heavily restricted globally. Encountering it in modern retail cosmetics is grounds to avoid the product.
- IARC Monograph Vol 100F. Formaldehyde. 2012.
- SCCS Opinion on Formaldehyde (SCCS/1538/14). 2014.
Tolerability and safety
Irritation potential
HighAllergen risk
HighPregnancy
AvoidSkin types
Use with caution
Frequently asked questions
Is Formaldehyde safe during pregnancy?
Formaldehyde is not recommended during pregnancy. Consider an alternative from the same category.
What skin types is Formaldehyde for?
Use with caution in: normal, dry, combination, oily, sensitive.
Can Formaldehyde irritate the skin?
Yes, Formaldehyde has high irritation potential. Start at low concentrations, introduce gradually, and always use SPF during the day.
Can Formaldehyde cause an allergic reaction?
Formaldehyde has high allergen potential. Perform a patch test on the inner forearm 24 hours before facial application.