Moderate Preservative Sensitization Data Dermal Penetration

DMDM Hydantoin

INCI: DMDM HYDANTOIN

CAS Number
6440-58-4
Function
Preservative, Formaldehyde Donor
Safety Rating
MODERATE

Regulatory Status

🇪🇺 EU Status restricted
EU Max Conc. 0.6%
🇺🇸 US Status permitted
US Notes Permitted in the US with no federal concentration cap. Consumer backlash has driven many brands to self-restrict despite technical efficacy. Formaldehyde contamination from packaging is a separate concern.

For full compliance data across 55 jurisdictions, use the Substance Compliance tool.

Safety Data

Margin of Safety (MoS)
not established
Dermal Absorption
low
Sensitization
moderate

Calculate MoS for your specific formulation with the MoS Calculator.

Sensitization Profile

Contact sensitization data for DMDM Hydantoin based on clinical patch test studies and IFRA standards.

Sensitization Rate
moderate
Allergen Class
preservative
EU Allergen Listed
no
Patch Test Positive Rate
1.0%
Cross-reactivity Group
formaldehyde-releaser-group
Reaction Type
contact-dermatitis

Source: ESSCA 2019/20; IVDK; FDA

Dermal Penetration Profile

Skin absorption and penetration characteristics of DMDM Hydantoin, relevant to systemic exposure and MoS calculations.

Absorption %
5-10%
Penetration Level
stratum-corneum
Penetration Depth
stratum corneum/epidermis
Molecular Weight
188.0 Da
Log P
-1.1
Systemic Absorption
minimal
Topical Bioavailability
3-8%
Safety Margin Factor
moderate
Vehicle Dependent
Yes — absorption varies by formulation

Source: CIR

Expert Verdict

DMDM Hydantoin is a formaldehyde-releasing preservative restricted to 0.6% in the EU with mandatory labeling when free formaldehyde exceeds 0.05%, creating sensitization risk for formaldehyde-allergic individuals; avoid in sensitive-skin formulations.

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Concern Level: Moderate

Regulatory Flags

preservative formaldehyde-releaser contact-allergen eu-restricted labeling-required avoid-sensitive-skin

Frequently Asked Questions

Is DMDM Hydantoin safe in cosmetics?

DMDM Hydantoin is a formaldehyde-releasing preservative restricted to 0.6% in the EU with mandatory labeling when free formaldehyde exceeds 0.05%, creating sensitization risk for formaldehyde-allergic individuals; avoid in sensitive-skin formulations. The EU classifies DMDM Hydantoin as "restricted". Safety rating: MODERATE.

Is DMDM Hydantoin allowed in the EU?

DMDM Hydantoin EU regulatory status: restricted. Maximum allowed concentration: 0.6%. This is based on EU Regulation 1223/2009 and its amendments.

What does DMDM Hydantoin do in cosmetics?

DMDM Hydantoin functions as: Preservative, Formaldehyde Donor. It is classified as a Preservative in our database. CAS number: 6440-58-4.

What is the Margin of Safety for DMDM Hydantoin?

not established The Margin of Safety (MoS) is calculated using SCCS methodology. A MoS above 100 is generally considered safe. Use the MoS Calculator tool to calculate MoS for your specific formulation and product category.

Compliance Tools

Check DMDM Hydantoin compliance across multiple jurisdictions:

🔬
Ingredient Decoder
Paste a full ingredient list for instant analysis
 🌸
82 Allergen Checker
Check for EU declarable fragrance allergens
 🧪
Substance Compliance
Check compliance across 55 jurisdictions
 🧮
MoS Calculator
Calculate Margin of Safety using SCCS methodology
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Heavy Metal Limits
Compare limits across jurisdictions

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