Inherently Flame Retardant (IFR)
An IFR fabric has flame resistance achieved naturally or with a chemical introduced to be an integral part of the fabric’s fiber, such that the fabric meets the requirements of a government’s flame retardancy standard. This flame resistance cannot be washed out and will never leach out. The treatment results in an inherent flame resistance for the life of the fabric. These fabrics can be water washed or dry cleaned.
Flame Retardant (FR)
A FR fabric has always been treated with a chemical to increase its resistance to ignition, making it acceptable to a flame retardancy standard. The chemical, however, is water soluble so these fabrics cannot be water washed or allowed to get damp. Sometimes, these fabrics can be dry cleaned.
Non Flame Retardant (NFR)
A NFR fabric cannot be treated with a chemical so that it meets any of the standards for flame resistance. These fabrics are seldom used on stages or, if they are, they are used in limited quantities and with special precautions prearranged with the local fire marshal.
Any fabric is certified as FR or IFR only if its composition has not been changed by the addition of any substance such as adhesives, sizing, paint, dyes, inks or anti-staining coatings. Any such addition voids the flame retardancy certification of the fabric. Each of these additions needs it own certification of flame resistance as well as the final composition needs separately to be certified.
Accumulations of dust and other air-borne particles, as well as frequent handling with bare hands, contribute to the degradation of the flame retardant character of any fabric. For this reason, flame retardant fabrics should be checked periodically.