What Is An Arc Flash?

An arc flash is an unwanted explosion resulting from an electric current leaving its intended path and going to either the ground, or another conductor commonly due to many potential reasons.

Some possible causes:

  • Poor installation
  • Condensation
  • Material failure
  • Corrosion

The New Safety Standard

The National Fire Protection Association (NFPA) updates NFPA 70E every three years to enhance the safety of people working in al types of work plants.  A hazard assessment is needed before determining the appropriate protection level of PPE needed.

Determining PPE for the workplace

In order to properly adhere to the new regulations regarding PPE one must follow one of two methods.

Engineering analysis:

An engineering analysis places the results on the equipment label based on incident energy (calories per square centimeter at working distance) and then the worker would then need to use PPE with an appropriate Arc Thermal Performance Value (APTV).  For example, if equipment had a rating of 9.2-calorie hazard on the label, the worker would need to select APTV with at least a 9.2-calorie hazard as well.

Table Method:

Depending on the hazard risk category assigned, the PPE may differ, and there’s a few steps needed to get there.  The closer one is to an arc, for example, the higher the risk of serious injury; so a few categories need to be determined in order to be well prepared. 

Workers must first look at Table 130.7(C)(15)(A)(a) to decide if arc flash PPE is required. If there is an arc flash hazard, workers then refer to Table 130.7(C) (15)(A)(b) or 130.7(C)(15)(B) to find the appropriate PPE category. They then refer to Table 130.7 (C)(16) which lists the clothing and other PPE required for that category.  If the task is unable to be found in these tables, then an engineering analysis must be performed.

Employers must also be aware of NFPA standards and are required to:

  • Train employees on proper use of PPE
  • Enforce use of PPE
  • May have to pay for PPE

Refer to the NFPA 70E for make sure you are up to date, and your workers are properly protected