Evigrade
DrugsCosmetic ingredientsCalculatorsInteractionsEvigrade SkinEvigrade Meds ↗
ConditionsJournalMethodologyPro for practitioners
ESRU

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

F

Topical application

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.
How to read tiers A–F
  • FDocumented harm for this route of administration

Tolerability and safety

Irritation potential
High
Allergen risk
High
Pregnancy
Avoid
Use with caution
Normal, Dry, Combination, Oily, Sensitive

About this ingredient

Formaldehyde (formic aldehyde, methanal) is the simplest aldehyde, a potent preservative and disinfectant. Historically used in shampoos, nail polishes, keratin hair-straightening products ("Brazilian straightening"). Carcinogenicity. IARC 2006 classified formaldehyde as a Group 1 carcinogen (confirmed human carcinogen) based on increased rates of nasopharyngeal cancer and leukemia in industrial and healthcare workers (formalin pathologists, embalmers, furniture makers). EU regulation. Regulation 1223/2009 banned formaldehyde as a standalone preservative in EU cosmetics since 2019. Only formaldehyde-releasers (DMDM Hydantoin, Imidazolidinyl Urea, Diazolidinyl Urea, Quaternium-15, Bronopol) are allowed – release trace formaldehyde on degradation. Mandatory "releases formaldehyde" labeling from July 2026 at concentrations above 0.001%. Nail polish is the only category where up to 0.2% formaldehyde is permitted as a hardener. Allergy and irritation. One of the most frequent contact allergens in cosmetics – 2-3% of patients in the ESCD patch-test panel. Mucosal, respiratory, and ocular irritation. In hairdressers and beauticians – occupational disease and asthma risk. Pregnancy – avoid (AVOID). Intrauterine exposure via inhalation in hairdresser mothers is linked to higher miscarriage risk (Quansah 2010). Lactation – no data, but avoid as a precaution. Alternatives. Phenoxyethanol, benzyl alcohol, sorbic acid, levulinic acid, gluconolactone-based preservatives for modern formulas.

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.

What is Formaldehyde and what does it do in cosmetics?

The simplest aldehyde.

What's the INCI name for Formaldehyde?

The INCI name is Formaldehyde. It may also appear as: Methanal, Methylene Oxide.

See Formaldehyde in a product composition right on the store page

The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.

Install the extension for free

Similar role in the formula

Published: · updated: