DMDM Hydantoin — Allergy Risk & Safety Profile
INCI: DMDM HYDANTOIN
Also known as: Glydant
Key Facts
- CAS Number
- 6440-58-0
- Category
- preservative
- Risk Level
- high
- Common Allergen
- Yes
- Max Concentration
- 0.6%
- Found In
- shampoo, conditioner, body wash
Is DMDM Hydantoin safe in cosmetics?
DMDM Hydantoin is rated high risk in cosmetic products. It is a known allergen that can cause contact dermatitis in sensitized individuals. Formaldehyde releaser — can cause contact dermatitis in formaldehyde-sensitive individuals. Safer alternatives include Phenoxyethanol, Sodium Benzoate, Potassium Sorbate. Commonly found in shampoo, conditioner, body wash.
What is DMDM Hydantoin?
Formaldehyde-releasing preservative. Slowly releases formaldehyde over time.
Allergy & Safety Information
DMDM Hydantoin is classified as a high-risk ingredient. It is a known cause of allergic contact dermatitis. Individuals with sensitive skin or a history of contact allergies should avoid products containing this ingredient. A patch test is recommended before first use of any product containing DMDM Hydantoin.
This ingredient is classified as high risk from an allergenicity perspective. It is a recognised cause of allergic contact dermatitis with a relatively high sensitisation rate in patch-tested populations. People with a history of skin reactions to cosmetics, or with conditions such as eczema or sensitive skin, should exercise particular caution.
About Preservative Ingredients
Preservatives prevent microbial growth in water-containing cosmetic formulas. Without them, products would spoil within days. However, preservatives are among the most common causes of allergic contact dermatitis — they must be present in high enough concentrations to be effective, yet that same efficacy can irritate sensitised skin.
Relevance for DMDM Hydantoin: If you react to one preservative, you may be cross-reactive to others in the same chemical family (e.g., isothiazolinones, formaldehyde releasers, or parabens). Checking the full preservative profile of every product you use is the most reliable way to identify your personal trigger.
How to Identify DMDM Hydantoin in Products
Cosmetic ingredients are listed by their INCI (International Nomenclature of Cosmetic Ingredients) name in descending order of concentration. To check whether a product contains DMDM Hydantoin, scan the ingredient list for its INCI name exactly as it appears above. Ingredients present at 1% or less may appear in any order after the 1% threshold.
Product types to prioritise checking: Shampoo, Conditioner, Body wash. These product categories are the most common sources of DMDM Hydantoin exposure based on formulation data.
Not sure if your products contain DMDM Hydantoin? Paste the ingredient list into the free ingredient checker to scan for DMDM Hydantoin and other allergens automatically.
Cross-Reactions
If you react to DMDM Hydantoin, you may also react to:
Safer Alternatives
These ingredients serve a similar function with lower allergy risk:
Frequently Asked Questions
Is DMDM Hydantoin safe for sensitive skin?
DMDM Hydantoin is a known allergen and is generally not recommended for sensitive skin. Consider patch testing before use.
What products contain DMDM Hydantoin?
DMDM Hydantoin is commonly found in shampoo, conditioner, body wash.
What does DMDM Hydantoin do in cosmetics?
DMDM Hydantoin functions as a preservative in formulations. Formaldehyde releaser — can cause contact dermatitis in formaldehyde-sensitive individuals.
Related Guides
Top 10 Cosmetic Allergens
Is DMDM Hydantoin on the list? See the full clinical ranking.
Preservative Allergy Guide
Which preservatives cause the most reactions and what to use instead.
How to Read Ingredient Labels
Decode INCI names and find hidden allergens in your products.
Find Your Skin Allergy Trigger
Step-by-step elimination method to identify your trigger.
Contact Dermatitis Guide
Symptoms, causes, patch testing, and treatment options.
Is DMDM Hydantoin causing YOUR skin reactions?
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