What is the difference between UL 94 and ASTM E84?

 

UL 94 is a standard developed by Underwriters Laboratories (UL) that is specifically designed to evaluate the flammability of plastic materials. The test method involves exposing a sample of the plastic material to a small flame ignition source for a specified period of time. The test evaluates the material's burning characteristics, including the rate of flame spread, the production of flaming drips, and the time for the flame to self-extinguish. The UL 94 standard classifies materials into different categories based on their burning characteristics, ranging from V-0 (most flame-resistant) to HB (least flame-resistant).

ASTM E84, on the other hand, is a standard developed by the American Society for Testing and Materials (ASTM) that evaluates the surface burning characteristics of building materials. The test method involves exposing a sample of the material to a controlled flame ignition source and measuring the rate of flame spread and smoke density. The ASTM E84 standard classifies materials into three categories based on their flame spread and smoke density properties: Class A, Class B, and Class C. Class A materials have the best fire resistance properties, while Class C materials have the least fire resistance.

 

In summary, UL 94 is a standard used to evaluate the flammability of plastic materials, while ASTM E84 is a standard used to evaluate the surface burning characteristics of building materials. The two standards have different test methods and evaluate different properties of materials.