Arc Flash

In this sample label, the incident energy available and the corresponding work distance (Incident Energy at 18" (cal/cm2): 16.4) is used, so the PPE category is not included. If the PPE category (1-4) were included, this incident energy value would be left off the label.

Arc Flash Label Requirements

Much of the information identified during a risk assessment should be placed on arc flash labels. These labels are affixed to electrical equipment that workers might need to perform work on while it is energized. The labels must meet the NFPA 70E requirements and should follow the formatting guidelines set forth in the ANSI Z535.4 Product Safety Signs and Labels standard.

ANSI-compliant hazard labels include “Warning” or “Danger” signal words as a header along with corresponding symbols and text.

These labels must also include several important pieces of information so workers can understand the arc flash hazard present and behave appropriately. First, the nominal system voltage should be listed. Next, the arc flash boundary, calculated during the risk assessment, should be listed. Finally, a statement about PPE should be included that makes it clear to workers what they should wear. This should be done by listing at least one of the following:

• The PPE category OR the incident energy available and the corresponding work distance (but not both)
• The minimum arc rating clothing must have
• PPE specific to the worksite
• The method used for calculating this information should also be documented.

Some workplaces choose to include shock hazard information on these labels as well, which can incorporate information about limited and restricted approach boundaries. An assessment date is often included, too.