How can I mark off arc flash boundaries?

When working on minimizing the risk of an arc flash in your facility, one of the first things you should do is take arc flash measurements. These measurements will identify how far away from the source of an arc flash one must be before the risk is no longer life threatening. According to the National Fire Protection Association, there are actually three separate arc flash boundaries that you should identify.

Arc Flash Boundaries

The three levels of arc flash boundaries are as follows:

  • Prohibited – This is the area closest to the source of the potential arc flash. Anyone in this area without high level personal protection equipment will be seriously injured, and could even die due to the arc flash exposure.
  • Restricted – This is the next closest area, and anyone in this area should still be wearing personal protection equipment. While the arc flash at this distance won’t typically be fatal, there are still serious hazards that should serve to keep people away.
  • Limited – At this distance the arc flash will likely only cause first or second-degree burns. Wearing personal protection equipment even at this distance is a good safety precaution.

Marking Arc Flash Boundaries

Whether you only measure off the prohibited section, or you measure all three levels as recommended by the NFPA, you will need to have a way to identify where the boundaries exist. Most companies today will mark the different distances using floor marking tape. This is an easy and affordable option that will allow people to see exactly where the different boundaries are so they can take the proper precautions.

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In most facilities, each of the different boundary markers will also indicate what type of personal protection equipment should be worn when crossing that line. It will also alert non-essential employees to stay out of that area if they don’t have a good work reason to be there. These boundaries will help to educate everyone who works in the area so that the danger can be kept to a minimum.

Using floor marking tape is not only an easy and affordable option, but it is also highly visible. On top of that, it is easy to remove and replace should a system get an upgrade so that the arc flash boundary is further away and needs to be adjusted.


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