Does the SCCS opinion support the idea that products preserved with DMDM hydantoin will release formaldehyde? Yes.

My partner Peta-Ann recently came across a post on Instagram by a blogger claiming DMDM Hydantoin is safe because it releases a tiny amount of formaldehyde, all of which converts to Methylene Glycol; thus, no free formaldehyde present in the product. She also compares the presence of formaldehyde in Pears, which is 32mg/Kg (32ppm).

Formaldehyde is a very touchy subject to my partner Peta-Ann Jain because one of her friends suffered much due to her regular exposure to tiny amounts of formaldehyde in her warehouse.

Well, what would you say, if a blogger with a large number of followers claims that we do not have to be concerned about formaldehyde in cosmetic preservatives? Or, should we explore this issue further?


Appearance Colorless liquid
Odor Mild
Freezing Point Degrees Celsius -11 C
Density @25 Degrees Celsius 1.158
pH as is 6.9
Formaldehyde content Combined (%) 17 -17.6%
Formaldehyde content Free (%) 0.5-2.0%

Source: (Final Report on the Safety Assessment of DMDM Hydantoin, n.d.)

DMDM Hydantoin is a formaldehyde donor in aqueous media, and formaldehyde is a potential carcinogen and irritant.

Formaldehyde is almost a colourless gas with a sharp, irritating odor even at very low concentrations (below 1 ppm). Because it has the tendency to polymerize, it is commonly used and stored in the aqueous solution, called Formalin. This solution contains up to 15% methanol as a stabilizer.

Most formaldehyde exposures occur by inhalation or by skin/eye contact.

  • According to OSHA permissible exposure limit (PEL) is = 0.75 ppm (averaged over an 8-hour work shift).
  • According to OSHA short-term exposure limit (STEL) is = 2 ppm (15 minute exposure)
  • NIOSH IDLH (immediately dangerous to life or health) = 20 ppm

The SCCS Opinion – Can DMDM Hydantoin be Mutagenic?

It is possible. As per the SCCS opinion on DMDM Hydantoin, “Furthermore, positive Ames test results were obtained for both substances (DMDM Hydantoin and Formaldehyde) with Salmonella strain TA-98 in these studies. Because of similar mutagenic potencies and the observation of positive results in the same bacterial strain, the mutagenic activity of the product is probably attributable to formaldehyde release. This probability is further supported by comparable mutagenic potencies of formaldehyde and a 55% DMDM Hydantoin product in the mouse lymphoma assay and positive results for the two in the chromosome aberrations assay” (Final Report on the Safety Assessment of DMDM Hydantoin, n.d.).

The SCCS Opinion – Can DMDM Hydantoin be an Irritant?

Clinical studies revealed some observations of skin irritation after challenge applications of DMDM Hydantoin formulations. It has been suggested that such clinical findings are related to the release of formaldehyde from DMDM Hydantoin (Final Report on the Safety Assessment of DMDM Hydantoin, n.d.).

Release of Formaldehyde 

As stated above both mutagenic and irritant properties of DMDM hydantoin clearly indicate that free formaldehyde can be released in the cosmetic product containing DMDM Hydantoin.

The SCCS Opinion Free Formaldehyde Content in a Cosmetic Product

As per the SCCS opinion, a formulation of a cosmetic product should ensure that free formaldehyde does not exceed 0.2%. This means that formaldehyde content in 100 ml of a product is 2000 ppm (Boyer et al., 2013).

The permissible limit of free formaldehyde is 2000 ppm in a cosmetic product and 0.75 ppm in the air we breathe.

How much or How Many PPM Formaldehyde Can be Released Through A Cosmetic Product in The Surrounding Air or to a Bodily Tissue/Organ, such as skin or scalp during the application?

The blogger argues that all the formaldehyde is converted to Methylene Glycol in the product. DOES IT? There are no approved analytical methods to measure that. 

Finally, based on the data summarized in this review, it should neither be assumed that MG (Methylene Glycol) and FA (Formaldehyde) are equivalent nor that MG converts 100% into FA under any condition of use” (Golden & Valentini, 2014).


Can Formaldehyde Stay in Water as a Monomer?

YES. There was an ASTM test method ASTM D6303-98, which covered the determination of the formaldehyde monomer concentration in water and wastewater, meaning under certain conditions and for a certain period, formaldehyde can stay as a monomer in water.

There are other identification and quantification methods to determine formaldehyde in aqueous samples (Dar et al., 2016).

Risks of Repeated Exposure to Formaldehyde Releasing Preservatives?

“Also, repeated exposure may result in local accumulation at the site of application, eventually resulting in a dose that induces an allergenic reaction. Lymph node responses were analyzed after short and prolonged exposure to formaldehyde donors; these chemicals/preservatives are highly reactive with proteins and may thus persist in the skin” (De Jong et al., 2007).

Considering all the above, a shampoo/conditioner preserved using formaldehyde-releasing DMDM Hydantoin may contribute to hair-loss or may not contribute to hair loss; both are hypothesises, which require fully regulated in-vivo studies for a few months to ascertain the outcome.

Class Action Lawsuit TRESemmé Keratin Smooth Shampoo Causes Hair Loss, Scalp Irritation and the SCCS Opinion

Considering the SCCS opinion, would you say the manufacturer or the formulator is responsible? Maybe or Maybe Not.

A formulator can look at the SCCS opinion on DMDM Hydantoin and use it as suggested.

Big Questions

  1. When was the last time the SCCS look at and test DMDM Hydantoin in cosmetics and renewed their opinion?
  2. Considering the possibility of the presence of free formaldehyde in cosmetic products and the risks of repeated exposure to formaldehyde-releasing preservatives, when the SCCS should review the use of DMDM Hydantoin in cosmetics?
  3. If all or almost all of formaldehyde is NOT converted to Methylene Glycol, how a manufacturer/testing lab will determine the presence of free formaldehyde (how many ppm) in the formulation before its opening, during storage, and during the product application?

As for me, I like to have thick, dense, and healthy hair. I would prefer not to use the products with DMDM Hydantoin 😊

Manoj (Josh) Jain


Boyer, I. J., Heldreth, B., Bergfeld, W. F., Belsito, D. V., Hill, R. A., Klaassen, C. D., Liebler, D. C., Marks, J. G., Shank, R. C., Slaga, T. J., Snyder, P. W., & Andersen, F. A. (2013). Amended Safety Assessment of Formaldehyde and Methylene Glycol as Used in Cosmetics. International Journal of Toxicology, 32, 5S-32S.

Dar, A., Shafique, U., Anwar, J., Waheed-uz-Zaman, & Naseer, A. (2016). A simple spot test quantification method to determine formaldehyde in aqueous samples. Journal of Saudi Chemical Society, 20, S352–S356.

De Jong, W. H., De Klerk, A., Beek, M. Ter, Veenman, C., & Van Loveren, H. (2007). Effect of prolonged repeated exposure to formaldehyde donors with doses below the EC3 value on draining lymph node responses. Journal of Immunotoxicology, 4(3), 239–246.

Final Report on the Safety Assessment of DMDM Hydantoin. (n.d.).

Golden, R., & Valentini, M. (2014). Formaldehyde and methylene glycol equivalence: Critical assessment of chemical and toxicological aspects. Regulatory Toxicology and Pharmacology, 69(2), 178–186.