UL900 Flammability Certification The UL 900 standard covers the requirements to determine the quantity of smoke generated and the combustibility of air filter units . The test is carried out on the unused filters, since the type of and level of particle loading greatly impacts flammability and smoke generation.
What is a Class 2 air filter?
UL 900 Class 2: Air filters which burn moderately when attacked by flame, or emit moderate amounts of smoke, or both.Jul 14, 2017