Is DMDM Hydantoin safe in cosmetics?
DMDM Hydantoin has a safety rating of "MODERATE" in our database. EU status: restricted. US status: permitted.
DMDM Hydantoin
INCI: DMDM HYDANTOIN
DMDM Hydantoin (CAS 6440-58-4) is a cosmetic preservative functioning as Preservative, Formaldehyde Donor. EU Regulation 1223/2009 status: restricted, max 0.6%. Industrial safety data is also available in the chemical safety database.
View industrial chemical safety profile for CAS 6440-58-4 →
Auto-generated CPSR Part A draft with source citations
Function
Preservative, Formaldehyde Donor
Safety Rating
MODERATE
Regulatory Status
EU EU Status
restricted
EU Max Conc.
0.6%
US 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 multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for DMDM Hydantoin.
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
Typical Use Concentrations
Reported concentration ranges per product category from SCCS/CIR/industry sources.
| Product Category | Typical Range | Max Reported | Source |
|---|---|---|---|
| Shampoo | 0.1–0.6 | 0.6 | CIR |
Additional Ingredient Properties
10 property records from structured ingredient metadata.
allergen_detail
{"eu_allergen_listed": "no", "allergen_class": "preservative", "cross_reactivity_group": "formaldehyde-releaser-group", "patch_test_frequency_pct": "1.0", "sensitization_rate": "moderate", "common_reaction_type": "contact-dermatitis", "ifra_restricted": "no", "source": "ESSCA 2019/20; IVDK; FDA"}
comedogenicity_detail
{"comedogenicity_rating": "0", "irritancy_rating": "3", "skin_type_suitability": "oily,combination", "acne_safe": "caution", "source": "Formaldehyde releaser"}
deodorant
{"cas_number": "6440-58-0", "ingredient_class": "antimicrobial_deodorant", "mechanism_of_action": "bacterial_growth_inhibition", "antiperspirant_efficacy_sweat_reduction_pct": "0", "deodorant_efficacy_hours": "24", "odor_reduction_pct": "60-80", "bacteriostatic": "yes", "bactericidal": "yes", "target_bacteria": "broad_spectrum", "microbiome_impact": "broad", "axillary_microbiome_effect": "varies b…
dermal_absorption
{"molecular_weight_da": "188.0", "log_p_value": "-1.1", "skin_penetration_level": "stratum-corneum", "penetration_depth": "stratum corneum/epidermis", "absorption_pct": "5-10", "systemic_absorption": "minimal", "penetration_enhancer": "no", "occlusion_effect": "no", "vehicle_dependent": "yes", "skin_barrier_effect": "neutral", "bioavailability_topical_pct": "3-8", "safety_margin_factor": "moderate…
ecotoxicity
{"biodegradable": "yes", "biodegradation_days": "14-28", "bioaccumulative": "no", "aquatic_toxicity_level": "moderate", "coral_reef_safe": "yes", "marine_toxicity": "moderate toxicity", "freshwater_toxicity": "releases formaldehyde", "endocrine_disruptor": "no", "persistent_organic_pollutant": "no", "microplastic": "no", "nano_particle": "no", "hawaii_banned": "no", "eu_restricted_environmental": …
microbiome_impact
{"microbiome_effect": "negative", "prebiotic": "no", "probiotic_compatible": "no", "antimicrobial_spectrum": "broad", "preservative_effect_on_microbiome": "Formaldehyde-releasing; severe disruption of skin microbiome diversity", "skin_flora_disruption": "severe", "gut_microbiome_risk": "low", "microbiome_recovery_time": "21-28 days", "selective_antimicrobial": "no", "pathogen_inhibition": "S. aure…
pediatric_safety
{"safe_for_newborn_0_6m": "avoid", "safe_for_infant_6_12m": "avoid", "safe_for_toddler_1_3y": "caution", "safe_for_child_3_12y": "caution", "safe_for_teen_12_18y": "yes", "pediatric_max_concentration_pct": "0.0", "adult_max_concentration_pct": "0.6", "pediatric_dermal_absorption_factor": "higher", "immature_skin_barrier_risk": "moderate", "oral_ingestion_risk": "moderate", "eye_irritation_risk": "…
ph_stability
{"optimal_ph_min": "4.0", "optimal_ph_max": "8.0", "stable_ph_min": "3.5", "stable_ph_max": "9.0", "degrades_above_ph": "9.5", "degrades_below_ph": "3.0", "ph_dependent_function": "Formaldehyde releaser; pH affects release rate", "formulation_note": "Less commonly used; regulatory concerns", "source": "SpecialChem 2025"}
Expert Verdict
Expert safety assessment and concern-level summary for DMDM Hydantoin.
Regulatory Flags
preservative
formaldehyde-releaser
contact-allergen
eu-restricted
labeling-required
avoid-sensitive-skin
Frequently Asked Questions
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.
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 multiple jurisdictions
MoS Calculator
Calculate Margin of Safety using SCCS methodology
Heavy Metal Limits
Compare limits across jurisdictions
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