What is it?

Formaldehyde is a naturally occurring organic compound with the formula CH2O (H-CHO). It is the simplest of the aldehydes (R-CHO) and is also known by its systematic name methanal. The common name of this substance comes from its similarity and relation to formic acid.” Wikipedia

What are the effects?

This substance belongs to the groups:

Most substances releasing formaldehyde, such as sodium hydroxymethylglycinate, urea formaldehyde, methenamine, and DMDM hydantoin will also be highlighted and tagged as formaldehyde by Curious Chloride’s scanner.

The compound was classified as a probable human carcinogen already in 1987 by the U.S. Environmental Protection Agency (EPA). Since then, more studies have been made and more organizations have issued the same classification on the compound. One example is the International Agency for Research on Cancer (IARC) that also classifies this substance as a human carcinogen.

The European Chemicals Agency (ECHA) classifies that this substance “is toxic if swallowed, is toxic in contact with skin, causes severe skin burns and eye damage, is toxic if inhaled, may cause cancer, is suspected of causing genetic defects, cause an allergic skin reaction, fatal if inhaled and causes serious eye damage.”

ChemSec’s SIN List, a database of chemicals likely to be banned or restricted in a near future, includes the substance as “classified as a possible carcinogen, also reported to be mutagenic and toxic for reproduction. It is been detected in both humans and the environment.”

Formaldehyde is banned in Japan and Sweden for use in cosmetics and toiletries. In the EU and Canada, formaldehyde is restricted. CosIng* has set the “maximum concentration in ready for use preparation” to 5 %.

Formaldehyde is also likely to contribute to the formation of nitrosamine contamination in products.

The Scientific Committee on Consumer Safety (SCCS) from the European Commission writes that “Aldehydes (especially formaldehyde) may catalyze the formation of nitrosamines from secondary amines through the intermediacy of imines. These transformations occur readily at pH values ranging from 5-10.”

The SCCS continues “The same applies also to formaldehyde donors like hydroxymethylurea and other formaldehyde releasing preservatives. Hydroxymethylsarcosine is a formaldehyde donor that may be expected to catalyse (its own) nitrosation. Thus, in addition to providing the nitrosation catalyst formaldehyde, so-called formaldehyde donor biocides can also be nitrosated as such to produce N–nitroso compounds.”

Formaldehyde was awarded Allergen of the Year in 2015 by the American Contact Dermatitis Society.

There are many different compounds produced by a mixture of urea and formaldehyde that will be marked as “may be animal derived”. There are also some formaldehyde resins which can be derived from insects that also will be tagged as potentially derived from animals.


Even though it is not listed on the list of ingredients, products with these substances may contain impurities from:

  • Nitrosamines –  Linked to endocrine disruption, cancer, organ system toxicity, and is prohibited to use in cosmetics in the EU and Canada.

*CosIng is the European Commission database for information on cosmetic substances and ingredients.

How is it used?

Formaldehyde is present everywhere around us; in building materials, walls, toys, washing & cleaning products, glues, paper coatings, pressed wood products, curtains, electronics, air fresheners, paints, furniture, etc.

Formaldehyde is also widely used in cosmetic products* and can be found in everything from shampoo, liquid baby soaps, to nail polish. The compound, and other preservatives releasing formaldehyde (FRP’s), is mainly used in water-based products to prevent microorganisms from developing.

We use the European Commissions definition of Cosmetics:
“Cosmetics range from everyday hygiene products such as soap, shampoo, deodorant, and toothpaste to luxury beauty items including perfumes and makeup”.

Read about the other ingredients.


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