Ive heard Auralex products are “Class B.” What does that mean?
The Standard for Surface Burning (ASTM E84 or NFPA 255) yields two numbers: “Flame Spread Index” and “Smoke Developed Index” These numbers are compared with three ranges called out in building and fire safety codes. The three ranges correspond to “Class A”, “Class B”, and “Class C.” (Some codes refer to these as “Class 1”, “Class 2”, and “Class 3.” The Class designations are interchangeable.) Depending on the results of the test, a material will fall into one of these three categories. “Class A” (or “Class 1”) is the best, indicating that a material is not likely to burn very much, but may produce some smoke. “Class C” (or “Class 3”) is the worst, indicating that a material will likely burn more and possibly even produce more smoke.
