There are two classifications of flame-resistant or FR apparel. The first is “flame resistant”—which is synonymous with “fire resistant,” so don’t be confused if you see those two terms used interchangeably. The other classification is “flame retardant,” which can also be called “fire retardant,” and that has an entirely different meaning. Neither of them is fireproof: both flame-resistant clothing and flame-retardant clothing are capable of catching fire. Some occupations will call for flame resistant clothing, some of flame retardant.
OSHA and ASTM Standards
OSHA (Occupational Safety and Health Administration) defines the standards for flame-resistant and flame-retardant apparel.
What distinguishes them is that flame retardant safety apparel has been chemically treated to slow combustion or ignition. They take time to catch fire, so you’ll have the time you need to escape danger without injury. Otherwise, flame-retardant clothing has all the same qualities as flame-resistant apparel.
In order to qualify as fire-resistant, clothing must pass the rigorous safety test conducted by the ASTM (American Society for Testing & Materials). Fire-resistant (and fire-retardant) fabric must be self-extinguishing. It needs to pass an ASTM vertical flame test: for twelve seconds, the fabric is suspended over a flame, then removed: the fire must extinguish within 2 seconds of removal. What ASTM tests for, in short, is the structural integrity of fabric to withstand direct exposure to fire, and its ability to prevent or minimize injury by self extinguishing once you’ve escaped the danger. FR fabric is specifically designed to resist breaking open and exposing under garments, though it’s recommended that you wear FR undergarments as well, and above all, avoid undergarments that are capable of melting with heat, such as polyester and a number of other synthetic materials. There are different ASTM tests depending on whether your fire-resistant clothing is meant to withstand arc fire (ASTM F1959) or flash fire (ASTM F1930), so it’s essential to make sure you’re purchasing the right FR clothes that fit your industry's particular requirements.
The goal of FR clothing is to allow you valuable time to escape danger and to help prevent or at least minimize injuries.
Wildland Fire Boots
Wildland fire boots adhere to different standards set by the NFPA (National Fire Protection Association) called NFPA 1977. These standards are intended to ensure the boots can withstand the harsh conditions of firefighting. Both municipal and wildland firefighting departments require boots to meet these standards. The NFPA isn’t simply a bureaucratic agency: their people have worked in fire departments and know exactly what it takes to protect firefighters.
Fire boots are classed as a kind PPE—a term that’s become all too well known during the pandemic: Personal Protective Equipment. Per the the NFPA 1977: Standard on Protective Clothing and Equipment for Wildland Firefighting, fire boots—firefighting footwear—must comply with a number specific and exacting standards.
1.) Flame Resistance. The boots cannot, melt, ignite, drip, and must be self extinguishing: the afterflame can’t last longer than two seconds.
2.) Heat Resistance. The boot must be able to resist heat: the boot needs to be able to withstand heat tests without delaminating or melting. In addition, it needs to possess Conductive Heat Resistance—specifically the sole surface inside cannot exceed 111 degrees Fahrenheit in heat tests, which last up to ten minutes. Likewise, the thread and laces (and fire boots require laces; they cannot be slip ons or pull ons) must be able to withstand heat without igniting, melting, or charring. This thread standard was created after 911, when firefighters’ boots delaminated because the thread couldn’t withstand the heat.
3.) Cut Resistance, Puncture Resistance, and Abrasion Resistance: The upper must be leather and the outsole needs to be able to withstand difficult wildland conditions.
4.) Slip Resistance: the outsole needs to be of rugged make to withstand melting—a Vibram sole or Vibram-type sole—but it also needs to be able to protect against slipping.
5.) Corrosion Resistance and Attachment Strength: All metal parts need to be able to resist corrosion; in addition, hooks and eyelets need to be tested for strength.
6.) Label Durability: labels need to remain legible and stay in place during fire tests.
NFPA 1971 sets a separate standard structural fires and proximity fires.
See our complete collection of FR clothing and footwear, including NFPA 1977-compliant boots, such as those from Danner boots and Thorogood boots, and FR jackets and bibs from Viking and Helly Hansen, and FR hoodies from Arborwear.