Like most building materials, carpet must meet certain government standards and codes for flammability. Since carpet covers such a large portion of an interior, it's especially important to understand the most important facts affecting resistance to fire.

• Nylon 6,6 fibers have the highest melting points (480 F) among manmade carpet fibers including nylon 6.
• Nylon 6,6 is self-extinguishing and will shrink away from a flame.
• If a match is dropped on a nylon 6,6 carpet the fibers will melt only in a small area around the match. Once the match extinguishes, the melting will stop.

Another popular test for flammability is the radiant panel flooring method. Here, the flame spread resistance of a carpet system - both the carpet and underlayment - is measured in a simulated corridor installation. The carpet system is placed inside the test chamber and a radiant heat panel (not a flame) is placed above one end of the carpet. The panel generates intense heat, igniting the sample. The total distance that the sample burns is measured and the critical radiant flux (CRF) is calculated. Each carpet system is tested three times to determine an average CRF. The higher the CRF, the better the flame resistance of the carpet system. This test is only applicable to carpeting in corridors.

In the radiant panel flooring test, carpet samples are rated according to the type of building in which they are used and whether or not the building has a water sprinkler system. Hospitals and other health care facilities have the most stringent flammability requirements. The most stringent requirement, Class I, requires a minimum CRF of .45 watts/cm2.