What Does Flame-Resistant Fabrics (FR Fabrics) Mean?
Flame-resistant (FR) fabrics are fabrics that do not easily catch fire or melt when exposed to fire or other ignition sources.
There are two primary categories of flame-resistant fabrics: inherently flame-resistant fabrics and chemically treated flame-resistant fabrics. Inherently flame-resistant fabrics have a chemical structure that makes them naturally resistant to fire. Chemically treated flame-resistant fabrics are made flame resistant by the application of a flame-resistant chemical (the underlying fabric may or may not also be flame resistant).
Flame-resistant fabrics are also known as fire-retardant fabrics.
Safeopedia Explains Flame-Resistant Fabrics (FR Fabrics)
Advanced occupational health and safety jurisdictions require workers to wear flame-resistant fabrics in workplace settings that contain significant fire hazards. In North America, fabrics that have certified fire resistance are referred to as being “FR-rated.”
To be qualified as FR-rated, a fabric product must be tested by a recognized testing laboratory. The tests used to determine the fire resistance of a given fabric must follow a recognized testing standard, such as ASTM F1930 - Standard Test Method for Evaluation of Flame Resistant Clothing for Protection Against Flash Fire Simulations Using an Instrumented Manikin.
FR testing is destructive in nature; this means that once a given piece of fabric is put in use, it cannot be tested again to ensure that its flame-resistant capabilities remain intact. For this reason, employers and workers have an obligation to inspect flame-resistant clothing and other fabrics for damage, and to cease using them if any is found. Chemically treated fabrics may also have a limited lifespan if the chemical treatment's protection is known to diminish over time.
The NFPA rates fabrics according to four different levels of flame resistance, and also standardizes the criteria used to determine the level of flame resistance that is necessary for employees to be able to work safely within a given workplace. The higher the FR rating, the greater the ability of the material to self-extinguish upon its removal from an ignition source.
Common flame-resistant fabrics include wool, Kevlar, and Nomex. Wool is the most common naturally occurring FR fabric. Chemically treated FR fabrics are typically made with a poly-cotton blend and are usually less expensive than inherent FR fabric; however, they also usually wear out faster. Beyond cost and durability differences, chemically treated fabrics generally protect against molten metal splash better than most inherent FR fabrics do.