ASTM F1506 vs. NFPA 2112: Understanding the Difference in FR Standards

When your crews work near energized equipment, flame-resistant (FR) workwear isn’t just part of the uniform; it’s critical protection. But not all FR standards are the same, and using the wrong one can leave workers exposed to serious hazards and put your site at risk for compliance issues.

This article breaks down the two most widely used FR standards in high-visibility apparel: ASTM F1506 and NFPA 2112. You’ll learn what each one is designed to protect against, where they apply, and why ASTM compliance is the right choice for jobsites where arc flash is the real danger.

What Are FR and AR Standards, and Why Do They Matter?

Before comparing standards, it helps to understand what flame-resistant and arc-rated actually mean, and why that difference matters on the job.

FR (Flame-Resistant) Clothing

FR clothing is built to resist ignition and self-extinguish once the flame source is removed. It protects workers exposed to sparks, heat, and open flames. The material is engineered not to melt, drip, or support continued combustion, even under repeated exposure. That protection is woven into the fabric itself, so repeated washing won’t affect the garment’s overall flame-resistant performance.

AR (Arc-Rated) Clothing

AR clothing is flame-resistant, but with added protection against electrical arc flash, which is a sudden, high-heat explosion caused by an electrical fault. Arc flashes can reach temperatures of up to 35,000°F and release dangerous levels of energy in milliseconds. Workers near transformers, circuit breakers, or energized panels face this risk regularly.

Understanding the gap between FR and AR is the first step. Now let’s look at the standard designed to close that gap for arc flash protection.

Learn More: How to Choose the Right FR Garment: A Guide to Flame-Resistant Workwear.

ASTM F1506: Built for Arc Flash Protection

ASTM F1506 is the go-to standard for protective apparel used around energized equipment. It was developed for electric utility workers, construction teams, and anyone exposed to arc flash hazards. These workers aren’t just carrying tools, they’re surrounded by live systems that can fail in unpredictable ways. 

The standard is written to make sure that fabric and finished garments provide real protection in these high-risk environments. It doesn't just look at one factor, it checks everything from flame behavior to strength after multiple washes.

Here’s what it covers:

• Arc rating (ATPV or EBT): The standard requires testing under ASTM F1959, which exposes fabric to a controlled arc flash and measures how much energy it can block before breaking open or transferring enough heat to cause a second-degree burn. ATPV (Arc Thermal Performance Value) or EBT (Energy Breakopen Threshold) must be clearly labeled.
• Flame resistance: Garments are tested using ASTM D6413, known as the vertical flame test. This checks whether the material continues to burn once the ignition source is removed. It also measures the char length and afterflame time.
• Durability and fit: High-visibility workwear doesn’t just need to protect, it has to hold up. The standard includes tests for tear strength, burst resistance, dimensional stability, and seam integrity after at least 25 washes. Colorfastness is also tested to ensure visibility doesn’t fade too quickly. That’s important in environments with sun exposure, dirt, and daily wear.
• Labeling: Every ASTM F1506 garment must include a label with the arc rating. This makes it easier for workers and safety managers to match the protection level to the hazard assessment. Labels must also note that the garment complies with ASTM F1506.

If your team works around energized conductors, transformers, or live electrical panels, this is the standard to trust. But electrical hazards aren’t the only danger on the job. For work environments facing different risks, there’s another standard to consider.

NFPA 2112: Designed for Flash Fire Conditions

NFPA 2112 serves a different audience. This standard was created for workers who face flash fire risks, usually in oil and gas, chemical processing, or refining. These fires happen fast. They're typically over in just a few seconds, but the heat they produce can be fatal without proper protection.

Flash fires aren’t caused by electricity. They’re fueled by flammable gases, vapors, or dust. A single spark or static discharge can ignite a vapor cloud, surrounding workers in intense heat for a brief but dangerous moment. NFPA 2112 focuses on full-body protection during these types of events. 

Here's how it works:

• Manikin testing: Garments are tested on a manikin equipped with heat sensors at dozens of points across the body. A controlled flash fire (lasting three seconds) is used to simulate real-world conditions. The sensors measure how much heat penetrates the garment and predict the percentage of body burn.
• 50% burn rule: To pass, garments must show no more than 50% predicted body burn. This doesn’t mean 50% is safe, it’s a minimum threshold. Many industries aim for far lower percentages when selecting workwear.
• Garment design and certification: NFPA 2112 requires third-party certification to ensure each product has passed the necessary tests. It also sets criteria for ignition resistance, fabric shrinkage under heat, and garment construction standards.

NFPA 2112 plays a critical role in industries like natural gas distribution and refinery operations, where flash fire is a constant risk. But if the danger on your jobsite comes from electrical systems, not flammable materials, this type of protection doesn’t align with the hazard. 

Kishigo’s Approach to FR Workwear

Different jobsites face different hazards. For industries focused on electrical work, ASTM F1506 is the standard that fits. It certifies that garments offer both flame resistance and arc flash protection, two essential safeguards for environments where thermal and electrical hazards can overlap.

This dual protection makes ASTM F1506 the right choice for many utility workers, construction crews, and public works teams operating around energized equipment. From switchgear to overhead lines, these tasks demand workwear built for both types of risks.

At Kishigo, we design flame-resistant workwear for crews who work where arc flash hazards are real, and mistakes aren’t an option. Every FR product we make meets ASTM F1506. That means it’s been tested, rated, and built to protect against electric arc hazards in the field. But compliance is just the starting point.

We build for the demands of the job:

• Durability that holds up. Reinforced seams, hidden fusing, and stress-point reinforcements mean our apparel lasts longer without compromising comfort.
• Comfort that works with you. Breathable mesh, flexible fabrics, and inclusive fits help crews stay focused and comfortable all shift long.
• Visibility where it matters. High-visibility colors and reflective striping are built into every design to keep workers seen in any light, on any site.

No exposed stitching. No oversized fits. No shortcuts. Just dependable apparel designed for electrical safety and built for real-world conditions. If your crews work around energized equipment, Kishigo has what they need: ASTM F1506-compliant, arc-rated, high-visibility workwear that’s ready for the job.

Contact us today to discuss your FR needs.