Fire Ratings The ASTM system classifies a carpet as Class 1 or Class 2, while the EN system is more stringent and detailed. With the EN system, letters A through F indicate how combustible the material is, with A being non-combustible to F being easily flammable.

Exception: Hotels and motels with direct to outside exits from all guests' rooms. Flammability requirements for carpet used as floor covering in all other occupancies shall meet a minimum value of 0.22 watts per square centimeter in all corridors and exits.

The word comes from Old French carpite 'heavy decorated cloth, carpet', from Medieval Latin or Old Italian carpita 'thick woolen cloth', which may derive from Latin carpere 'to card, pluck'. The meaning of the term carpet shifted in the 15th century to refer to floor coverings.