DMDMH - DMDM Hydantoin

I. Product Information

Product Name 1,3-Dihydroxymethyl-5,5-dimethylhydantoin

Synonyms DMDMH

Chemical Name 1,3-Bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione

IUPAC Name 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione

INCI Name DMDM Hydantoin

Molecular Formula C₇H₁₂N₂O₄

Molecular Weight 188.2

CAS No. 6440-58-0

EC Number 229-222-8

II. Product Properties

Property	Description
Appearance	White odorless powder (pure); colorless transparent liquid (55% commercial grade)
Antimicrobial Spectrum	Broad-spectrum efficacy against Gram-positive/negative bacteria, yeast, and mold
Mechanism	Dual action: ① Slowly releases formaldehyde for antimicrobial effect; ② N-hydroxymethyl group itself is an active antimicrobial moiety
Stability	Pure product stable at pH 6～8; 55% solution heat stable (up to 80℃), stable at pH 6.5～7.5; avoid reaction with amines or thiols under alkaline conditions
Solubility	Water 773 g/L (completely miscible); ethanol 564 g/L; hexane 0.2 g/L; excellent compatibility with cosmetic and detergent ingredients

Physical & Chemical Data:

Boiling Point: 198～200℃ (decomposes on boiling)
Melting Point: 90℃ (OECD)
Vapor Pressure (25℃): 9.0×10⁻⁶ mmHg
Density: 0.4 g/cm³ (21℃, pure) / 1.16 g/mL (25℃, 55% solution)
lgKow: -2.9 (extremely hydrophilic)
Flash Point: >100℃
Freezing Point (55% solution): -11℃
Nitrogen Content: 8.04%～8.34%

III. Quality Specifications

Test Item	Specification	Method
Appearance	White odorless powder (pure) / Colorless transparent liquid (55% solution)	Visual
Active Content	55%±2% (solution) / ≥99% (pure)	Titration
Aldehyde Content	17%～19% (as formaldehyde, 55% solution)	Sodium Sulfite Method
pH (20℃)	6.5～7.5 (55% solution) / 6～8 (pure)	pH Meter
Density (25℃)	1.16 g/mL (55% solution)	Densitometry
Freezing Point	≤-11℃ (55% solution)	Freezing Point Method
Flash Point	>100℃	Closed Cup
Heavy Metals (as Pb)	≤0.001%	Colorimetric
Free Formaldehyde	≤1% (controlled at low level)	Acetylacetone Method
Identification	IR spectrum matches reference standard	FTIR

Note: Available as 55% solution, pure powder, and other specifications upon request.

IV. Antimicrobial Performance (MIC Data)

Microorganism	MIC (mg/L)	Microorganism	MIC (mg/L)
Aspergillus niger	1455	Bacillus subtilis	727
Aspergillus flavus	1550	E. coli	291
Saccharomyces cerevisiae	1300	S. aureus	29
Brewer's yeast	1455	P. aeruginosa	291

Note: DMDMH shows excellent inhibition against Gram-positive bacteria (S. aureus MIC 29 mg/L); relatively weaker against mold and yeast (MIC 1300～1550 mg/L), requiring combination with other preservatives.

V. Applications

1. Cosmetics & Personal Care (Core Application)

Shampoos: Preservation; widely used in combination with IPBC or parabens
Conditioners/Shaving products: Mild preservation
Foundations/Lotions: Aqueous product preservation
Creams/Baby products: Low-irritation formulations
Sunscreens/Cleansers: Rinse-off products
Features: No skin or mucous membrane irritation; excellent hydrophilicity and compatibility with cosmetic/detergent ingredients

2. Coatings & Aqueous Polymers

Water-based coatings: Anti-mold and preservation
Water-based adhesives: Microbial contamination prevention
Dyes/Pigments: Preservation
Printing auxiliaries: Preservation

3. Metalworking & Industrial

Metal cutting fluids: Preservation (PT-13 type)
Industrial circulating water: Biocidal preservation
Oilfield water injection: Anti-corrosion treatment

4. Textiles & Fibers

Textile auxiliaries: Preservation
Fiber fabrics: US Patent 6077319 discloses etherification of DMDMH to fiber surfaces followed by chlorination to impart antimicrobial properties

5. Other Industries

Inks: Preservation
Paraffin oils: Preservation
Wood: Anti-mold treatment
Leather: Preservation

VI. Regulatory Compliance & Safety

Certification/Regulation	Details
EU ECHA	Approval applications submitted under Directive 98/8/EC (BPD) or Regulation (EU) No.528/2012 (BPR) for PT-6 (In-can preservatives) and PT-13 (Metalworking fluids); currently under review
Cosmetic Applications	Globally recognized cosmetic preservative with over 30 years of use history
US Patent	US 6077319: Antimicrobial treatment method for fiber fabrics

Toxicity Data:

Endpoint	Data
Rat acute oral LD₅₀	2000 mg/kg
Rabbit acute dermal LD₅₀	>2000 mg/kg
Rat inhalation LC₅₀ (4h)	>377.8 mg/L
Rainbow trout LC₅₀ (96h)	283 mg/kg
Bluegill LC₅₀ (96h)	95 mg/kg
Daphnia EC₅₀ (48h)	20.4 mg/L
Skin Irritation	No skin or mucous membrane irritation

Usage Precautions:

Formaldehyde is highly reactive and may react with amine- or thiol-containing surfactants or emulsifiers under alkaline conditions, affecting preservation efficacy
Avoid direct contact with strong alkaline substances
Recommended for use in combination with IPBC or parabens to enhance inhibition against mold and yeast

VII. Packaging & Storage

Packaging: 200kg/plastic drum (55% solution) / 25kg/fiber drum (pure); custom sizes available

Storage: Cool, dry place (≤25°C), sealed, away from light; avoid contact with amines, thiols, and strong alkalis

Shelf Life: 24 months (sealed)

Transport: General chemical; handle with care to prevent damage

VIII. Key Advantages

Dual antimicrobial mechanism: Slow formaldehyde release + direct N-hydroxymethyl action for synergistic effect
Extremely low irritation: No skin or mucous membrane irritation; high safety profile
Excellent hydrophilicity: Water 773 g/L complete miscibility, lgKow -2.9, perfect compatibility with aqueous systems
Excellent formulation compatibility: Compatible with cosmetic/detergent ingredients; synergistic with IPBC or parabens
Low temperature stability: 55% solution freezing point -11℃, suitable for low-temperature storage and transport
Heat stability: Good heat resistance (up to 80℃), compatible with conventional processing
Wide applications: Covers cosmetics, coatings, metalworking, textiles, papermaking, and other fields