DMFu Global Control: Essential Safety Rules Unveiled

Dimethyl fumarate (DMFu), as a highly effective anti-mold agent, was once widely used in products such as leather, textiles, and footwear. However, DMF easily sublimates at room temperature, and contact with or inhalation on human skin may cause severe allergic reactions, such as redness, itching, burns, and even respiratory discomfort.

Characteristics and hazards of DMFu

Chemical properties

Dimethyl fumarate (DMFu) is a white crystalline powder at room temperature, soluble in organic solvents, and has a significant inhibitory effect on mold, yeast, and other bacteria. It was once the core ingredient of the “Mycoxin” moisture reprodger.

Core application scenarios

Application areas	Typical products/forms	Risk exposure pathways
Textiles and footwear	Leather uppers, knitted insoles, moisture-proof bags for down jackets	Material residues penetrate through skin contact
Furniture and home furnishings	Sofa fillings, wardrobe moisture-proof bags, wooden furniture coatings	After evaporation, it comes into contact with skin or inhales gas
Packaging and storage	Shoe boxes/clothing boxes have built-in mold-resistant pouches	Damaged packaging bags cause direct contact
Food processing	Illegally added anti-mold agents for flour products	Digestive tract intake can cause internal organ corrosion

Health hazards

• Skin damage: Contact dermatitis can occur within 24–48 hours of contact, presenting as erythema, blisters, and burning pain, with a long course and frequent recurrence;
• Systemic toxicity: Accidental ingestion can corrode the gastrointestinal mucosa, and long-term inhalation of volatile substances may damage the respiratory tract;
• Child risk: The allergy rate in children after exposure to DMFu products is more than three times higher than that of adults.

Core control standards

EU: Zero-tolerance ban

• REACH regulation: Consumer goods must not exceed DMFu content of 0.1 mg/kg (including finished products, raw materials, and packaging, applicable to all consumer goods that may come into contact with the human body). ）；
• Industry standard: Oeko-Tex Standard 100 requires “no detection” for baby textiles (detection limit< 0.01 mg/kg).

China: Mandatory testing by field

• Footwear standards: China’s mandatory standards GB 25038-2024 “General Safety Requirements for Footwear” and GB 30585-2024 “Technical Specifications for Safety of Children’s Shoes” also clearly specify limits for dimethyl fumarate, specifying that its content must not exceed 0.1 mg/kg.
• Textiles: FZ/T 01142-2021 requires DMFu content ≤0.1 mg/kg;
• Food sector: DMFu is explicitly listed as an illegal additive.

The United States and other regions

• California Proposition 65: Classify DMFu as a “known allergenic substance.” If DMFu release in a product causes daily exposure exceeding 0.5μg, a warning “may cause skin allergies” must be prominently displayed on the packaging;
• CPSC regulatory requirements: DMFu content in children’s products (children’s clothing, toys, strollers) must be ≤0.1mg/kg, and moisture-proof packaging containing DMFu is prohibited
• Canada: The Dangerous Goods Act classifies DMFu as a “corrosive substance” and prohibits its use in furniture and clothing. Concentrations exceeding 0.1 mg/kg are considered hazardous products

Testing technology upgrades and practical recommendations

Key changes in the old and new standards

GB/T 26713-2025 “Chemical Test Method for Footwear—Determination of Dimethyl Fumarate (DMFu)” is the latest national standard issued in China for the detection of dimethyl fumarate in footwear products, and it has been officially implemented since September 1, 2025. The main upgrades of GB/T 26713-2025 compared to the 2011 version are as follows:

Standard	GB/T 26713-2011	GB/T 26713-2025
Detection limits and quantitative limits	The detection limit is about 0.1 mg/kg	The detection limit was reduced to 0.05 mg/kg, and the quantification limit was 0.1 mg/kg, with significantly improved sensitivity
Detection methods	Only the GC-MS/GC-MS/MS methods are specified	Added HPLC method as a routine detection option, while retaining GC-MS/MS for arbitration
Sample pretreatment	Ultrasonic extraction using ethyl dehydrated acetate	Switching to acetone ultrasonic extraction (60°C), distinguishing between “standard steps” (simple matrix) and “complex matrix steps” (such as leather).
Sampling requirements	No detailed regulations were provided	Digestive tract intake can cause internal organ corrosion
Quality control and reporting	Includes chapters on recovery rate, precision, detection limits, and more	Deleted content such as recovery rate, precision, and detection limits, and added a new “Test Report” chapter (Chapter 10).
Blank test	Includes blank trials	Removing blank test requirements
Instruments and reagents	No detailed regulations on glassware and other items are provided	Explicitly reference GB/T 12810 (Laboratory Glass Measuring Instrument Calibration) and specify the steps for preparing standard solutions
Applicable material range	Mostly for single materials like leather	Expand to include all shoe components (upper, sole, insole, closure finished leather , textiles, and other composite materials).

Corporate compliance follows three steps

1. Source control: Suppliers are required to provide CNAS/ILAC-certified DMFu test reports;
2. Batch sampling: Batch sampling for high-risk items such as leather and PU leather;
3. Emergency handling: Products exceeding standards must be immediately discontinued from sale and can be re-tested after degradation through cleaning and ventilation.

Incorporating DMFu testing into routine quality inspections (costing about 1%–3% of the goods value) is not only a compliance requirement but also key to enhancing trust in the international market. Hangmei Testing reminds companies: proactively comply and avoid luck-based mentality to ensure stable overseas expansion.