Diazolidinyl Urea — Allergy Risk & Safety Profile

Name: Is Diazolidinyl Urea Safe? Allergy Risk & Alternatives
Creator: SkinDetekt

INCI: DIAZOLIDINYL UREA

Also known as: Germall II

🔴 High Risk

Key Facts

CAS Number: 78491-02-8
Category: preservative
Risk Level: high
Common Allergen: Yes
Max Concentration: 0.5%
Found In: moisturizer, foundation, sunscreen

Is Diazolidinyl Urea safe in cosmetics?

Diazolidinyl Urea is rated high risk in cosmetic products. It is a known allergen that can cause contact dermatitis in sensitized individuals. Formaldehyde releaser. Can cause both irritant and allergic contact dermatitis. Safer alternatives include Phenoxyethanol, Sodium Benzoate, Potassium Sorbate. Commonly found in moisturizer, foundation, sunscreen.

What is Diazolidinyl Urea?

Formaldehyde-releasing preservative. Releases more formaldehyde than Imidazolidinyl Urea.

Allergy & Safety Information

Diazolidinyl Urea 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 Diazolidinyl Urea.

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.

Allergen Note: Formaldehyde releaser. Can cause both irritant and allergic contact dermatitis.

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 Diazolidinyl Urea: 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 Diazolidinyl Urea 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 Diazolidinyl Urea, 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: Moisturizer, Foundation, Sunscreen. These product categories are the most common sources of Diazolidinyl Urea exposure based on formulation data.

Not sure if your products contain Diazolidinyl Urea? Paste the ingredient list into the free ingredient checker to scan for Diazolidinyl Urea and other allergens automatically.