Arc Flash PPE Requirements
There are several Arc Flash PPE requirements that must be met before any electrical related work is performed in the workplace. Knowing what PPE to wear and when to apply it in order to meet the Arc Flash PPE requirements is easy once you have acquired all the necessary information.
Personal protective equipment (PPE):
Any protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer’s body from injury. The hazards addressed by protective equipment include physical, electrical, heat, chemicals, biohazards, and airborne particulate matter. Protective equipment may be worn for job-related occupational safety and health purposes, as well as for sports and other recreational activities. “Protective clothing” is applied to traditional categories of clothing, and “protective gear” applies to items such as pads, guards, shields, or masks, and others.
The purpose of personal protective equipment is to reduce employee exposure to hazards when engineering and administrative controls are not feasible or effective to reduce these risks to acceptable levels. PPE is needed when there are hazards present. PPE has the serious limitation that it does not eliminate the hazard at source and may result in employees being exposed to the hazard if the equipment fails.
Any item of PPE imposes a barrier between the wearer/user and the working environment. This can create additional strains on the wearer; impair their ability to carry out their work and create significant levels of discomfort. Any of these can discourage wearers from using PPE correctly, therefore placing them at risk of injury, ill-health or, under extreme circumstances, death. Good ergonomic design can help to minimise these barriers and can therefore help to ensure safe and healthy working conditions through the correct use of PPE.
Arc Flash Hazard Risk Categories:
Arc Flash hazard/risk category is specified as a number representing the level of danger, which depends upon the incident energy (the amount of energy impressed on a surface, a certain distance from the source, generated during an electrical arc event). The category ratings range from 0 to 4 where category 0 represents little or no risk, and category 4 signifies the greatest risk. Above category 4 (>40 calories/cm2) all equipment is considered too dangerous to work on energized because of the tremendous pressure blast. All parts of the body that may be exposed to the arc flash need to be covered by the appropriate type and quality of PPE.
This site is designed to provide you with the proper Personal Protective Equipment requirements, or PPE for each category.
What PPE Should I wear?
Selection of appropriate PPE, given a certain task to be performed, is normally handled in one of two possible ways. The first method is to consult a hazard category classification table, like that found in NFPA 70E. Table 130.7(C)(9)(a) lists a number of typical electrical tasks are various voltage levels and recommends the category of PPE that should be worn. For example when working on 600 V switchgear and performing a removal of bolted covers to expose bare, energized parts, the table recommends Category 3 Protective Clothing System. This Category 3 system corresponds to an ensemble of PPE that together offers protection up to 25 cal/cm2 (105 j/cm2 or 1.05 MJ/m2). The minimum rating of PPE necessary for any category is the maximum available energy for that category. For example, a Category 3 arc-flash hazard requires PPE rated for no less than 25 cal/cm2 (1.05 MJ/m2).
The second method of selecting PPE is to perform an arc flash hazard analysis to determine the available incident arc energy. IEEE 1584 provides a guide to perform these calculations given that the bolted fault current, duration of faults, and other general equipment information is known. Once the incident energy is calculated the appropriate ensemble of PPE that offers protection greater than the energy available can be selected. Reducing the frequency and severity of incidents should be the first option and this can be achieved through a complete arc flash hazard analysis or assessment.