Why do carpets have to be tested for 16CFR1630 surface flammability?

Federal law requires carpets to comply with flammability standards and other requirements, and manufacturers and importers of carpets intended for general purpose must certify in a General Certificate of Conformity (GCC) that the carpet has undergone testing or reasonable testing procedures to ensure compliance with the standard and/or is properly labeled in accordance with the standard, and that the carpet complies with the applicable standard.
16 CFR 1630 Test Standard – Standard Name:
16 CFR 1630:SURFACE FLAMMABILITY OF CARPETS AND RUGS
16 CFR 1630 Test Standard – Scope of Application:
It is suitable for carpets used in homes, offices or hotels, which are not adhered by mechanical methods (such as nails, etc.), with a one-way size of more than 1.83 m and a surface area of more than 2.23 square meters.
16 CFR 1630 Test Standard – Test Methods:
The test consists of exposing eight 9-inch ×9-inch condition specimens to timed burning pads in a designated test chamber.
The instruments and test materials required to perform the test are specified in 16 CFR §§ 1630.4(a) and 1631.4(a).
In general, each specimen is placed in the center of the chamber floor with the seam side facing up. Place the flattened frame on the specimen and place the methylamine timed burner on a flat surface in the center of the 8-inch flattened frame hole. Touch the top of the plate with a lit match, lighter, or other equivalent ignition source to ignite it. Let the test continue until:
(1) All flames and glows disappear, or
(2) The flame or smoke has reached within 1 inch of the flattened frame.