What is the ASTM flame rating?

 

ASTM flame retardant grades are specified by ASTM E84 (Standard Test Method for Surface Burning Characteristics of Building Materials) and ASTM D635 (Standard Test Method for Rate of Burning and/or Extent and Time of Burning of Plastics in a Horizontal Position) Test methods and evaluation criteria are determined. The following are the main classifications of ASTM flame retardant grades and their meanings:

 

1. Class A: This class indicates that the material has the highest flame resistance and produces the least flame and smoke when burned. The material has a Burning Velocity Index of not more than 25 and a Smoke Development Index of not more than 450 in the ASTM E84 test.

 

2. Class B: This grade indicates that the material has high flame resistance and produces less flame and smoke when burned. In the ASTM E84 test, the material has a Burning Velocity Index exceeding 25 but not exceeding 75, and a Smoke Development Index not exceeding 450.

 

3. Class C: This grade indicates that the material has certain flame-retardant properties, and produces more flames and smoke when burned. In the ASTM E84 test, the material has a Burning Velocity Index exceeding 75 but not exceeding 200, and a Smoke Development Index not exceeding 450.

 

In addition to the above three grades, there are some other ASTM flame retardant grades, such as Class D, Class E and Class F. These grades are usually used in special fields and specific applications to determine the flame retardancy of materials according to specific test methods and evaluation standards.

 

The assessment of ASTM flammability ratings is critical to ensuring the reactivity of materials and products in a fire. By choosing flame-retardant grade materials that meet the needs, the speed of fire spread can be reduced, the harm of fire to people and property can be reduced, and a safer working and living environment can be provided. Therefore, ASTM flame retardant grades play an important guiding role in the design, selection and use of materials and products.