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None of the current regulations governing the use of FR clothing specifically require the use of FR thread for embroidery applications. However, recommends the use of flame-resistant thread for embroidery or emblem attachments.

Commonly Used Terms

  • Flame Resistant (FR) - A fabric or product that resists ignition and self-extinguishes after removal of the ignition source.
  • Vertical Flame Test - A basic test that determines whether or not a fabric is FR by measuring how much of the fabric is consumed after 12 seconds of flame exposure.
  • Arc Rating - The value for fabrics that describes their performance under exposure to an electrical arc discharge. Testing determines when the amount of exposure results in a 50% probability of causing the onset of second-degree skin burn. The arc rating is expressed in cal/cm2. It can be either an ATPV or an EBT.
  • ATPV - The Arc Thermal Performance Value of a fabric shown in cal/cm2.
  • EBT - The Energy of Breakopen Threshold. The cal/cm² at which the fabric breaks open before it reaches its ATPV.

Protective Clothing Chart

Hazard Risk Category or PPE Category Clothing Description Required Minimum Arc Rating of PPE Cal/cm2
Arc-rated FR Long-sleeve shirt and FR pants or FR coverall. 4
Arc-rated FR Long-sleeve shirt and FR pants or FR coverall. 8
Arc-rated FR Long-sleeve shirt and FR pants or FR coverall, and arc flash suit selected so that the system arc rating meets the required minimum. 25
Arc-rated FR Long-sleeve shirt and FR pants or FR coverall, and arc flash suit selected so that the system arc rating meets the required minimum. 40