3D printing filaments with a fire-resistant superpower are ideal for products that may be in contact with a source of fire.
There are many classifications of fire-resistance. A common system that is used to test fire-resistance is the UL94 rating system. Ul94 is the standard for tests for flammability of plastic materials for parts in devices and appliances. It generally tests the response to a small open flame and/or a radiant heat source. The UL94 test rating is given as a V score (V-0, V-1, V-2) based on the time taken for the vertical material to extinguish a flame at the bottom of the sample. The sample must not burn to the top or drip molten material capable of igniting a cotton indicator.
It is important to distinguish between Fire Resistant and Flame Retardant. Fire resistant materials are made from inherently non-flammable materials so will burn very slowly or not at all. On the other hand, flame retardant materials have been chemically treated to be slow burning or self-extinguishing. Flame retardant materials can technically be made from any plastic as long as it has been treated with the appropriate chemicals whereas a fire resistant material must be inherently non-flammable in its chemical structure.