Flame retardant doesn't mean fire proof. That is a common misconception. A standard UL flame test on filter media classified as fire retardant means the media is self-extinguishing within a certain number of square inches. So, if you were to put a flame to the media, it can still ignite. However, once the flame is removed, the media will self-extinguish.This is an important piece of information as the dust collected on the filter itself is still flammable in many cases. For example, if you are capturing wood dust or buffing lint. The dust itself can sustain a flame. So flame retardant media is just one step in making your dust collector fire resistant. In many applications, you still need a spark arrestor and sprinkler or fire suppression system.\nMany manufacturers offer fire retardant or non-fire retardant filter media. At Damn Filters, we always supply our filters with fire retardant media as a standard. It’s an easy way to protect our customers from inadvertently ordering a non-FR filter.Call one of our experts if you have questions and need an unbiased opinion.