What are the different ratings and classifications under UL94 and ASTM E84?

 

1. UL94 V-0: The material self-extinguishes within 10 seconds after the ignition source is removed, and no flaming drips are allowed. This is the highest level of flame retardancy.

 

2. UL94 V-1: The material self-extinguishes within 30 seconds after the ignition source is removed, and no flaming drips are allowed.

 

3. UL94 V-2: The material self-extinguishes within 30 seconds after the ignition source is removed, but flaming drips are permitted.

 

4. UL94 HB: The material burns slowly, and the flame propagation rate is less than a specified limit.

 

5. UL94 5VA: This is the highest rating, indicating excellent flame resistance. The material must undergo additional tests for resistance to ignition, flame propagation, and dripping.

 

 

1. Class A: The material has low flame spread and low smoke production. It has the best fire performance.

 

2. Class B: The material has moderate flame spread and smoke production. It has a lower fire performance compared to Class A.

 

3. Class C: The material has high flame spread and smoke production. It has the least fire performance among the classifications.

 

The ratings and classifications provided by UL94 and ASTM E84 are used to assess the performance of materials in terms of flame spread and fire resistance. They provide a standard measure to evaluate the flammability and safety of different materials used in various applications.