FR Clothing: What You Need to Know

Whether you’re an electrical worker exposed to dangerous thermal arcs or in the oil and gas industry where flash fires sometimes occur, flame-resistant (FR) clothing is an important part of your job. The journey your gear makes from the fabric mill to your closet includes a lot of important stops, and, make no mistake, not all FR garments are created equal. Whether you’ve worn FR gear your entire working career or are new to the industry, this post explains where FR standards come from, important ratings you need to understand, and the details you should be looking for when picking out your next garment.

But first, a disclaimer:

Flame-resistant (FR) clothing is often referred to as Personal Protective Equipment, or PPE. Those two terms – FR and PPE – are used interchangeably in this post.

The Major Players
Before we jump into specifics, it’s first important to understand the major players in the PPE industry. Simply put, the manufacturing, certification, and policing of PPE standards falls to a few distinct groups that must work together so that conditions are safer for all.

  1. Trade Associations: The National Fire Protection Association (NFPA) is the leading information and knowledge resource on fire, electrical and related hazards. According to their website, they publish more than 300 consensus codes and standards that all aim to minimize the possibility and effects of fire and other risks. Two documents in particular –70E and 2112 – outline standards for safety apparel in the workplace. It’s important to note that the NFPA consensus standards are NOT laws, however the U.S. Occupational Safety and Health Administration (OSHA) has generally accepted them as industry practices and references the standards in citations.
  2. Apparel Manufacturers: Using the standards established above, FR apparel manufacturers – like Carhartt – must then design and produce safety garments that will be sold to workers in various industries. It’s important to note that manufacturers must only meet minimum requirements outlined in the NFPA’s consensus standards. That leaves some wiggle room in the construction of their garments. Translation: While all PPE garments must be cleared to meet minimum safety requirements, not all FR garments are built with the same quality and attention to detail.  
  3. Certification Partners: After the NFPA and manufacturers have done their jobs, a 3rd party must help certify PPE garments to ensure they provide the level of safety their labels say they do. That’s where organizations like Underwriters Laboratories (UL) step in. For instance, all Carhartt FR garments that meet NFPA 2112 standards for the oil & gas industry have been classified by Underwriters Laboratories (UL). This process includes exhaustive testing on the fabrics and garments produced by manufacturers to ensure that if an accident happens, the garment will perform as expected.

Employers: The last piece of the puzzle are the companies on the front line hiring workers and doing the hazardous work. Their job is to help employees assess jobsite risks as well as ensure employees are adequately equipped to do their jobs safely. They do this by communicating what level of FR gear employees are expected to wear and overseeing employees while they’re on the job to ensure they’re compliant. In fact, the reason brands like Carhartt include large FR labels on the outside of their FR garments is so supervisors can quickly verify their workers are wearing the correct gear for the job.

The Ratings:
When shopping for FR gear, you’ll notice a series of ratings and acronyms within a product’s description or on its label. Here’s what those ratings mean:


The term ATPV stands for Arc Thermal Performance Value. In simple terms, it states the level of protection provided by flame resistant clothing as measured in cal/cm2. The higher an arc rating, the more protective a garment is. An ATPV arc rating means that you have a 50% chance of a 2nd degree burn if exposed to an electric arc with the same number of calories of heat. The fabric will usually not break open unless exposed to energy levels higher than the arc rating.


The term Ebt stands for Energy Break-Open Threshold. It’s used when ATPV cannot be measured due to FR fabric breaking open during particular tests. In other words, Ebt is similar to ATPV, but it’s a rating that is established when breakopen occurs before a 2nd degree burn can form on the wearer.

Whew, that’s a lot to take in!

The bottom line is that when FR gear is tested, one of two things will occur: The garment will break open (creating an Ebt rating) or it will remain intact (creating an ATPV rating). These ratings are used to categorize FR clothing so you know what types of clothes will protect you from the hazards you could face on the job.

The Standards
We mentioned above that the NFPA establishes standards for workplace apparel and the two most recognizable standards in the FR apparel industry are NFPA 70E and NFPA 2112.

NFPA 70E applies to clothing used as protection from thermal hazards produced by an electric arc, while the NFPA 2112 is a standard for clothing used as protection from industrial, short-duration thermal exposure hazards (commonly referred to as “flash fires”).

In other words, NFPA 70E was established to cover electrical workers who work on or near parts that may produce an arc flash, while NFPA 2112 was developed to protect industrial workers in the oil or gas fields who may be exposed to a flash fire.

In NFPA 70E, different PPE categories are outlined so employers and workers know which gear is right for their job. The categories range from 1 to 4, with a PPE category 1 providing the least protection and a PPE category 4 providing the most. The NFPA 70E standard issues these categories based on the electrical maintenance tasks being performed and each category represents a specific range of ARC protection. The table below outlines the categories and their corresponding ratings.

Protective Clothing Chart

protective clothing chart

For instance, at CAT2 would include ARC ratings greater than or equal to 8 cal/cm2, but less than 25 cal/cm2.

Please note: If you’ve worn PPE gear for a while, you may notice CAT (short for “category”) has replaced the acronym HRC (short for “Hazard Risk Category”) on product labels and descriptions. This change happened after NFPA 70E updates in 2015. Both reference the level of protection an FR garment provides. You’ll see the new CAT classification on Carhartt’s garment labels, packaging and hangtags, catalogs, and within product descriptions on websites.

Shopping for PPE Products
If you’ve ever shopped for flame-resistant apparel, you know that it can be costly, which shouldn’t be a huge surprise when you consider all of the research, development and testing that goes into the production of an FR garment. At first glance, flame-resistant clothing brands may appear to offer similar styles and designs. But if you look closer and do your research, you’ll see that not all PPE gear is created equal.

The differences begin as early as the fabric mills. Some manufacturers purchase fabric from mills who buy their unfinished “base” fabrics from third parties. Carhartt, for instance, partners with a number of qualified suppliers who manufacture their own base fabric that has a more consistent weight, thickness, dye shade and color retention, and an overall higher level of reliability. These qualities may be hard to identify before buying FR apparel, however, over extended periods of use the difference will become clear as certain fabrics simply won’t maintain their look and feel.

Design & Construction

Anyone who has worn FR apparel will tell you that you’ll have to sacrifice a certain level of comfort to wear compliant clothing. But things are getting better. Advancements in fabric design and technology have helped produce lighter gear that maintains workplace compliance. The design and “cut” of the garments have improved too, making for clothes with an improved fit that move with a worker better than before.

Such advancements are apparent in Carhartt’s Flame-Resistant Force® Hybrid Shirt. The 100% cotton FR jersey knit is a lightweight PPE solution that features fast drying technology, a side-seamed construction that minimizes twisting, and Carhartt’s patented Force® technology that fights odors. On top of all those features, it maintains a CAT2 rating that meets the performance requirements of NFPA 70E and is UL® Classified to NFPA 2112.

Even how an FR garment is sewn together matters too and can be a major factor when choosing which brand to buy. Gear that is poorly sewn or “single-stitched” is less likely to hold up to the wear and tear of a workday. When safety is key, the last thing you want are ripped seams or loose threads hanging from your body. The best bet is to look for garments that are “triple-stitched” that feature “reinforced” pockets.

Other Features

Other features that may be overlooked on an FR garment include its zippers, buttons and even the reflective tape used on certain high-visibility styles. The standards discussed earlier in this post do not explicitly prohibit the use of metal zippers or closures on FR garments. But if your personal safety is key, don’t you want your clothing manufacturer to go the extra mile? Carhartt, for instance, uses YKK Zippers that are certified by the UL and are NFPA 2112 compliant. Small details to look for that can make FR gear safer include:

  • FR melamine buttons – a plastic button that is shatterproof, fireproof and incredibly light.
  • FR-rated thread – sewing thread that has been treated and rated for FR garments.
  • Nomex® FR zipper tape – material applied to metal zippers and other closures to make them flame and heat resistant.
  • 3M™ tape used on high-visibility garments that is NFPA 2112 approved.

Discounted FR Gear and Factory 2nds

Because flame-resistant clothing can sometimes be expensive, it’s not uncommon for workers to shop for discounted products, including garments with minor factory defects. Often called a Factory 2nd, this classification of clothing includes styles that didn’t meet the factory’s strict production guidelines. Most times, these garments have minor imperfections that make them inconsistent with other products in that style.

Just because an FR-rated item has a discounted price or is classified as a Factory 2nd, does not make it any less compliant with the standards established by the NFPA. Bottom line: If a fabric or garment does not pass a flame-resistant test, it WILL NOT be released into the market. End of story. A best practice is to ensure any PPE gear you buy – discounted or not – features the proper certification label and category distinction required by your employer.

Next Steps
If all that information seemed a little overwhelming, don’t worry, we’ll simplify it.  Here’s a quick rundown of FR facts that industry newbies and seasoned veterans alike will find helpful:

  • Your employer will tell you what level of FR clothing you need to do your job. Labels on FR-apparel are typically sewn on the outside of garments so that supervisors can see that you’re wearing compliant gear. In a situation where multiple FR garments are layered together, it may not be immediately clear what the arc rating for that combination is. For that reason, Carhartt tested a number of popular garment combinations so that shoppers know the real rating of their ensemble. View the Carhartt Layered Arc Rating Reference Guide >
  • The National Fire Protection Association (NFPA) establishes consensus codes and standards that aim to minimize jobsite risks related to fire and other hazards. The NFPA 70E standard covers electrical workers, while the NFPA 2112 was developed to protect industrial workers in the oil or gas fields. Learn more about the NFPA Standards >
  • Not all FR gear is created equal. Yes, it must ALL pass strict safety guidelines before it can be sold to a consumer, but there are features unrelated to flame or arc flash protection that can make certain styles and brands more comfortable, longer lasting and more dependable than the competition. Shop Carhartt FR >
  • Discounted or Factory 2nd products can be a popular buying choice for budget-minded shoppers. As long as these products feature the necessary certification labels, they’re just as compliant as full-price products. Just be aware you may be buying a product with a slight fabric imperfection. Shop Factory 2nds FR Gear >

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