Arc Flash Suit: Choosing the Right Protective Gear

By R.W. Hurst, Editor

Arc Flash Suit

An arc flash suit is a type of personal protective equipment (PPE) designed to protect individuals from the hazards of arc flash. An arc flash is an electrical explosion or discharge that occurs when a current travels through the air between two conductors or between a conductor and the ground.

Arc flash can release tremendous energy, generating intense heat, light, and pressure waves that can cause serious injuries or fatalities. The purpose of an arc flash suit is to shield workers from the harmful effects of an arc flash, including burns, electrocution, and other injuries.

Arc flash suits are made from flame-resistant materials designed to cover the entire body, including the head, face, and hands. They are typically made of multi-layered fabrics, such as Nomex or Kevlar, that provide thermal insulation and protection from arc flash. Arc flash suits also have a hood or face shield, gloves, and safety glasses to protect the worker's face and eyes.

Arc flash suits are commonly used by electrical workers, electricians, and others who work with or around high-voltage electrical equipment, such as switchgear, transformers, and circuit breakers. They are essential to any electrical safety program and can help prevent serious accidents and injuries.


What is an arc flash suit made from?

Arc flash suits are made from special flame-resistant fabrics that provide thermal insulation and protection from the intense heat, light, and pressure waves generated by an arc flash. The most commonly used fabrics for arc flash suits are Nomex and Kevlar.

Nomex is a synthetic fiber made by DuPont known for its heat-resistant and flame-retardant properties. It can withstand high temperatures and is often used in protective clothing for firefighters, industrial workers, and military personnel. In addition, Nomex fabric is lightweight, breathable, and has excellent arc flash protection properties, making it a popular choice for arc flash suits.

Kevlar is another synthetic fiber made by DuPont that is known for its strength and durability. It is often used in bulletproof vests and other protective equipment. Kevlar fabric is also heat-resistant and flame-retardant and has excellent arc flash protection properties. Arc flash suits made from Kevlar are typically more durable and long-lasting than those made from Nomex.

In addition to Nomex and Kevlar, other materials that may be used in arc flash suits include carbon fibre, PVC, and neoprene. The choice of material will depend on factors such as the level of arc flash protection required, the environment in which the suit will be used, and the worker's specific needs.


Arc Flash Suit Selector

Arc flash clothing requirements dictate the choice of the proper PPE. The higher the risk assessment, the higher the arc rating your PPE needs to meet.

The National Fire Protection Association NFPA 70E specifies four PPE categories. These categories correspond with the NFPA 70E electrical safety clothing requirements.

Regarding clothing specifications under the Canadian Standard for Electrical Safety (CSA Z462) arc rated PPE of 75 cal, 100 cal and 140 cal are all combined into a separate category 5.


What kind of rating does an arc flash suit have?

Arc flash suits are rated based on their level of protection, which is determined by the amount of incident energy the suit can withstand without causing injury to the wearer. Incident energy is a measure of the thermal energy generated by an arc flash and is typically expressed in units of calories per square centimeter (cal/cm²).

The National Fire Protection Association (NFPA) has established a set of standards, known as NFPA 70E, that outline the requirements for electrical safety in the workplace, including using arc flash protective equipment. NFPA 70E specifies four categories of arc flash protection, each of which corresponds to a specific range of incident energy:

  1. Category 1: Minimum arc rating of 4 cal/cm²
  2. Category 2: Minimum arc rating of 8 cal/cm²
  3. Category 3: Minimum arc rating of 25 cal/cm²
  4. Category 4: Minimum arc rating of 40 cal/cm²

Arc flash suits are typically rated to one of these categories based on their protection level. The rating of the suit will be printed on a label attached to the garment and will indicate the maximum level of incident energy that the suit is designed to protect against. Therefore, workers should always choose an arc flash suit that is appropriate for the level of hazard they will be exposed to, based on a hazard assessment and job analysis.


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