About FR

What is FR?

FR stands for flame resistant or the ability for the material to self extinguish once the ignition source is removed. Non-FR material and clothing essentially becomes fuel to any flame and can cause more damage than the original fire itself would have without the added material fuel. FR textiles & clothing are designed to protect the wearer by preventing or slowing the ignition of flame & flash fire. FR fibres can now prevent or reduce ignition and mean that while the garment may burn, it will never burn to the wearer nor continue to burn (self-extinguishing) once the active flame is gone.

What are the hazards?

Flash Fire: A rapidly moving flame front which can be a combustion explosion. It can occur in an environment where fuel & air become mixed in adequate concentrations to combust (includes combustible dust). Flash fires have a heat flux of approx. 84kw/m² for a relatively short period of time, typically under 3 seconds.

Flash fire temperatures range from 540°C-1040°C (1000°F-1900°F)

Arc Flash: The light & heat produced from an electric arc supplied with sufficient electrical energy to cause substantial damage, harm, fire or injury. It is a violent event that is a combination of energy being released creating an explosion & oftentimes flying debris. Events are typically over a short duration but can reach 35,000°F.

Arc Flash temperatures can be up to 19,000°C/35,000°F

Who wears FR clothing?

People who work in hazardous or potentially hazardous environments such as electricians, electrical utility workers, oil & gas refinery workers, firefighters or anyone working with or near chemicals or combustible dust environments.

Molten Metal/Welders – Liquified metal hazard created from metal processing and welding activities.

What are FR standards?

NFPA 70E/CSA Z462 – Standard for Electrical Safety in the Workplace

  • ATPV (Arc Thermal Protective Value) - The incident energy on a material or multilayer system of materials that results in a 50% probability that sufficient heat transfer through the tested specimen is predicted to cause the onset of a 2nd degree skin burn injury based on the Stoll curve, cal/cm²
  • EBT (Energy Breakopen Threshold) – The incident energy on a material or multilayer system of materials that results in a 50% probability of breakopen

ASTM 1506 – Standard performance specification for flame resistant and arc rated textile materials for wearing apparel for use by electrical workers exposed to momentary electric arc and related thermal hazards.

CGSB 155.20 – Workwear for protection against hydrocarbon flash fire

NFPA 2112 – Standard on flame resistant garments for protection of industrial personnel against flash fire

NFPA 1971 – Standard on protective ensembles for structural firefighting and proximity firefighting

How is FR clothing categorized?

ARC Flash PPE Categories
  • Category 1: Min 4 cal/cm²
  • Category 2: Min 8 cal/cm²
  • Category 3: Min 25 cal/cm²
  • Category 4: Min 40 cal/cm²