By Jayden Mark
There are many professions, even DIY and leisure activities, that require fire-retardant (FR) clothing. Despite the importance of this critical safety gear, many are unaware what makes a particular garment safe from burning or smoldering.
FR Material Used for Different Purposes
So many of us use FR clothing every day without any understanding of what it is or how it works. Essential, FR clothing is designed to protect you from the dangers presented by arcs, explosions, and flames. Since the fabrics used to make FR clothing are so important, I would like to share my research on the topic.
You may not be aware that not all fabrics used to make FR clothing are equal. Fire retardant PPE worn by welders may have different requirements to those worn by emergency responders or people working in the electrical industry.
There two Types of FR Clothing
While I refer to fire resistant and fire retardant clothing, the terms flame resistant and flame retardant are just as commonly used. It all means the same thing.
What are the Fire Retardant Fabrics Used to Make FR Clothing?
Many natural and synthetic fabrics can be coated with fire retardant chemicals that help extinguish flames as they begin to burn. Other types of fire retardant fabrics rely on specially formulated fibers that help prevent smoldering and burning.
Non-combustible fabrics used to make FR clothing act by converting gasses and tar into carbon which inhibits its ability to burn.
The myriad of fire retardant fabrics can become overwhelming. To help you understand what thee are, and how they may differ, I’ll be providing a brief description of the more common FR fabrics used for clothing, gloves, masks, and hoods.
Developed by the Dutch company, Azko Nobel in the 1970s, Twaron is a strong, heat-resistant para-aramid synthetic fiber. It is similar to Kevlar and Nomex which are also commonly used to manufacture FR apparel.
While regular nylon is flammable and will produce molten drops when burnt, additional chemicals can be used to make flame retardant nylon fibers. The most common method of producing flame retardant nylon 6 fibers involves adding phosphorus-based compounds, like red phosphorus and magnesium oxide.
Ployhydroquinone-diimidazopyridine (PIPD), commonly known as M5 fiber, was developed by Azko Nobel in the Netherlands and is produced by DuPont in the US. It is a fire retardant aramid with an incredibly high tensile strength. It also has a high resistance to chemicals, making it ideal for FR clothing worn by workers who handle chemicals.
Manufactured by DuPont, Kevlar is similar to Nomex, another DuPont fire retardant product. Because Kevlar has a higher cut-resistance and improved thermal properties, it is ideal for FR gloves and sleeves.
Cotton is a natural fabric with a fairly high resistance to burning and smoldering. However, untreated cotton is not a fire retardant material. To make cotton FR clothing, several types of coatings can be used, these include:
Coated cotton FR clothing is often preferred because it is usually more comfortable, being soft and cool. The coatings used may be damaged by some detergents.
This is an oxidized Polyacrylonitrile (PAN) fiber, a synthetic polymer that does not melt or burn under normal conditions. It is considered a more environmentally-friendly fire retardant fabric because bromide/halide compounds are not used in the manufacturing process.
Originally manufactured by the Norwegian company, Daletec, primarily for the North Sea oil rigs, Dale Antiflame FR clothing is sold in over 100 countries and is used for all types of flame retardant garments. It is revered for its comfort, durability, and environmentally-friendly manufacturing processes.
Manufactured by Teijin Aramid, Technora is similar to Kevlar and other Aramids. It has a high resistance to chemicals and is very durable.
This is a meta-aramid, used in many FR applications including clothing. The durable fabric is also soft, making it more comfortable to wear.
CarbonX is a comfortable, non-abrasive fire retardant fabric. It is an excellent option for FR apparel that is worn close to the skin.
This is a versatile FR fabric that is available in a variety of weights and weaves for different applications. There are several options for improved fire protection, durability, and comfort.
This synthetic copolymer has been in production since 1949. It is strong, soft, and highly resilient. It also has great resistance to chemicals and solvents.
Kermel is a polyamid-imide FR fabric and is similar to meta-aramids. It is relatively soft with high fire retardant qualities, often used for the outer layer of firefighting suits.
PBI is a lightweight FR fabric with low thermal conductivity. It offers excellent break open thermal protection and won’t degrade in temperatures up to 1300°F.
The National Fire Protection Association (NFPA) coordinates fire protection standards. This forms the basis for most fire protection legislation and safety standards.
In order for fabric to be certified as fire retardant in the US, it must be tested according to ASTM D6413 standards. This requires that the fabric be tested with a vertical flame and may not char for more than 4-inches. Post-incandescence, or smoldering, may not last more than 2 seconds.
Fire retardant PPE can have one or more safety ratings. This will depend on the type of PPE and the region where it has been tested and certified. You should look for any of the following safety ratings for certified fire retardant PPE: