DMDM HYDANTOIN
Commonly Found In
Overview
DMDM Hydantoin is a formaldehyde-releasing preservative used in rinse-off and some leave-on cosmetics. It works by slowly releasing small amounts of formaldehyde to prevent bacterial and fungal growth. The EU allows it at up to 0.6% with a mandatory 'contains formaldehyde' label if released formaldehyde exceeds 0.05%. FDA permits use in the US; Japan also allows it.
Also known as: 1,3-bis(hydroxymethyl)-5,5-dimethylhydantoin, DMDMH, dimethylol dimethyl hydantoin, Glydant
Key Benefits
Functions solely as a preservative; preserves product safety and shelf life. No direct skin-benefit claims are supported by evidence. May help with scalp hygiene indirectly by preventing microbial contamination.
Supporting Research
- β’ CIR Expert Panel (1988, updated): Assessed DMDM hydantoin as safe at concentrations up to 0.6% based on released formaldehyde levels
- β’ Warshaw EM et al. (2013): Patch test data identified DMDM hydantoin as a relevant contact allergen in a subset of cosmetic-sensitive patients
Skin Compatibility Ratings
Comedogenic Rating
Non-comedogenic; water-soluble preservative with broad-spectrum antimicrobial activity.
Source: CIR Expert Panel safety assessment
Irritancy Rating
Moderate irritancy/sensitization potential due to formaldehyde release; EU requires 'contains formaldehyde' label when released formaldehyde >0.05%
Source: CIR Expert Panel; published patch-test literature
Typical Use Concentration
Range
0.1β0.6%
Optimal
0.2β0.4%
EU Annex V permits up to 0.6% with label requirement. US FDA permits use; no federal concentration cap but CIR assessed safe at β€0.6%.
Works Well With / Avoid
Works Well With
Use With Caution
EU Annex V max 0.6%; mandatory 'contains formaldehyde' label if released free formaldehyde >0.05%. Not for use in leave-on products in some interpretations. Avoid combining with other formaldehyde-releasing preservatives in excess of regulatory limits.
Commonly Found In
Global Regulation Summary
Overview of current status across major international markets.
Detailed Regional Status
| Region | Status | Max Conc. | Conditions | Source |
|---|---|---|---|---|
| πͺπΊ EU | Allowed | - | - | Official β |
| πΊπΈ USA | Allowed | - | - | Official β |
| π―π΅ Japan | Allowed | - | - | Official β |
| π°π· Korea | Unknown | - | - | Official β |
| π¬π§ UK | Banned | - | Follows EU regulations (V/33) | Official β |
π Why Regulations Differ
Permitted in EU (with labeling) and US at up to 0.6%. Consumer and regulatory concern over formaldehyde release has led to widespread voluntary reformulation in the US despite legal allowance.
Regulation Analysis
Regional Agreement
Banned in UK but allowed in EU, USA, Japan.
Category Comparison
There are 157 ingredients in the PRESERVATIVE category. 99% are banned in at least one major market.
Strictness Ranking
πΏ Natural Sources
Synthetic only. Not found in nature.
π How It's Made
Synthesized by reacting hydantoin with formaldehyde and water. The reaction produces 1,3-dimethylol-5,5-dimethylhydantoin, a formaldehyde-releaser that slowly hydrolyzes to release free formaldehyde.
π Uses in Cosmetics
Used at 0.1-0.6% in shampoos, conditioners, and body washes as a preservative. Works by slowly releasing formaldehyde to prevent bacterial growth. Banned in EU cosmetics. Allowed in the US at up to 0.6%.
π¬ Other Applications
Used in industrial water treatment, metalworking fluids, paints, and adhesives as a preservative and antimicrobial agent.
π‘ Fun Facts
- β’ DMDM Hydantoin was commonly used in popular shampoo brands until the 2010s, when consumer pressure led to reformulations
- β’ Class-action lawsuits against major cosmetic brands in the US (2021-2023) alleged DMDM Hydantoin in shampoos caused hair loss, though scientific evidence remains inconclusive
- β’ It releases formaldehyde more slowly than other releasers like quaternium-15, making it more stable in alkaline formulations
Data Sources
- β’ EU Cosmetics Regulation 1223/2009 Annex V entry 33
- β’ CIR Expert Panel β Safety Assessment of DMDM Hydantoin
- β’ Warshaw EM et al. (2013) β Patch test data, North American Contact Dermatitis Group
Last data verification: 2026-04-16
Related Ingredients
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BENZOIC ACID
BUTYLPARABEN
CETRIMONIUM BROMIDE
CETRIMONIUM CHLORIDE
CHLOROPHENE
Learn More
Frequently Asked Questions
What is DMDM HYDANTOIN used for in cosmetics?
DMDM HYDANTOIN is primarily used for preservative in cosmetic products. The ingredient is commonly found in various cosmetic products to prevent microbial growth.
Which countries regulate DMDM HYDANTOIN?
DMDM HYDANTOIN is banned in UK. The ingredient is freely allowed in EU, JP, US.
Are there alternatives to DMDM HYDANTOIN?
Due to regulatory restrictions on DMDM HYDANTOIN, cosmetic manufacturers often use alternative ingredients with similar functions. For preservative, alternatives may include other approved ingredients in the same category. Consult product labels for specific formulations, and look for products compliant with your region's regulations.
Where can I find official regulation information about DMDM HYDANTOIN?
Official information about DMDM HYDANTOIN regulations can be found on government websites: EU CosIng database, US FDA Cosmetics page, Japan MHLW cosmetics standards, UK Government cosmetics guidance, and Korea MFDS. Always verify regulatory status with these official sources before making formulation decisions.
Disclaimer
The information on this website is for educational and informational purposes only and is not intended as medical advice. While we strive for accuracy based on official government databases, cosmetic regulations change frequently. Always consult with a qualified professional or refer to the latest official regulatory documents for compliance. We are not responsible for any actions taken based on the information provided here.