Use NFPA 70E classifications to determine PPE requirements

Answered by Rich Gojdics, regional market manager, Westex Inc., Chicago.

Implementing a complete electrical safe-work practices program is involved and complex. Developing focus teams, becoming familiar with hazardous assessment processes, conducting training, establishing protective boundaries and labeling equipment can be painstakingly time-consuming without any real activity occurring to establish an electrical safe-work practices policy.

One option to accelerate results from these activities while protecting employees is to implement the required personal protective equipment   not as the final step after hazard assessment, training and labeling have been completed, but as an initial step, using the NFPA 70E Hazard/Risk category classifications and protective clothing tables, or using the simplified two-category flame-resistant clothing system.

The NFPA 70E Standard for Electrical Safety in the Workplace is a general consensus standard that establishes safe electrical work practices. It includes lists of typical electrical job tasks and classifies these jobs into five categories based on hazard level/risk, with charts detailing the PPE needed to protect to the level of the hazard for each category.

Both the Hazard/Risk category classifications and the PPE requirements, as well as the simplified two-category approach, have been widely used. This is due in part to their ease in helping determine what level of PPE is required to protect workers from the hazard potential of the tasks or jobs in each of the hazard risk categories. The simplified two-step approach requires a minimum arc rating   also known as an ATPV of 8 for "everyday work clothing" and 40 for "switching clothing." All flame-resistant fabrics are, or can be, tested to measure the amount of incident energy required (in cal/cm2) to predictably cause second-degree burns under the fabric.

The typical program supplies a daily wear, flame-resistant garment with an arc rating higher than 8, thereby meeting the clothing performance requirements of Hazard/Risk categories 0, 1 and 2 as a single layer. Companies that have conducted fault-current studies have found, and industry experts agree, that 80 to 90 percent of typical industrial electrical jobs fall into these three categories. Daily wear clothing refers to shirts, pants and coveralls made from flame-resistant fabrics that comply with NFPA 70E requirements and can be worn all day, every day.

Daily wear clothing can be supplemented with arc flash "switching" clothing that meets the performance requirements of Hazard/Risk category 4. Switching clothing refers to the arc flash gear designed of multiple layers of flame-resistant fabrics to provide protection from the significantly higher incident energies expectant in NFPA 70E Hazard/Risk categories 3 and 4.

Flame-resistant clothing options can be simple: People working on or near energized electrical equipment wear single layer HRC 2 clothing (ATPV>8) at all times, and supplement with HRC 4 (ATPV>40) switching clothing when the arc hazard is more than 8 calories. Taking action to implement protective clothing on an accelerated basis demonstrates to employees your commitment to safety, and demonstrates to OSHA that your company is serious about addressing the electrical hazards present in your workplace and you are taking steps toward completing an electrical safe-work practices policy within your company.