Classification and Hazard Status of PU Foam in International Transport and Trade

Polyurethane foam adhesive is classified as a dangerous good under international transport regulations. Its hazard classification varies with packaging form and the presence of flammable propellants.

Aerosol Formulations (UN 1950)

When the adhesive is sold in an aerosol can, it contains compressed flammable gases (for example, 1,1-difluoroethane or isobutane) mixed with reactive foam precursors. Under the UN Model Regulations:

• UN Number: 1950

• Class: 2.1 (Flammable Gas)

• Labels: Flammable gas (GHS02), Pressurized container (GHS04)

• Emergency Response: F-D (fire), S-U (general)

• Packaging: Must follow aerosol-specific provisions; no fixed packing group

These requirements also apply under IATA’s Dangerous Goods Regulations for air transport and the IMDG Code for sea transport.

Non-Aerosol Liquid Adhesives (UN 1133)

Adhesives without compressed gas—typically in cartridges or bulk containers—are regulated as flammable liquids. Key details:

• UN Number: 1133 (Adhesives Containing Flammable Liquid)

• Class: 3 (Flammable Liquids)

• Packing Groups:

  • I for products with flash point < 23 °C and high viscosity

  • II when vapor pressure > 110 kPa

  • III for less volatile formulations

• Labels: Flammable liquid (GHS02)

• Quantity Limits:

  • Limited Quantities up to 5 L

  • Excepted Quantities (E1/E2/E3) based on flash point and vapor pressure

• Transport ADR: Category 3; Tunnel restriction code D/E

Best Practices for Handling and Transport

1. Consult the Safety Data Sheet (SDS): Always verify UN number, packing group, flash point, and specific handling instructions.

2. Packaging and Labeling:

   • Aerosols: Follow IATA DGR and IMDG aerosol packaging rules.

   • Liquids: Ensure correct labels, quantity limits, and stowage restrictions.

3. Storage and Use:

   • Keep away from heat, open flames, and direct sunlight.

   • Use in well-ventilated areas with appropriate personal protective equipment (PPE).

Summary

• Aerosol foam adhesives: UN 1950, Class 2.1 (flammable gas)

• Non-aerosol liquid adhesives: UN 1133, Class 3 (flammable liquids)

Strict compliance with labeling, packaging, transport, and handling regulations is essential for safety and regulatory adherence.