Choosing the Right PPE for Arc Flash Hazards

Arc flashes are a potentially deadly possibility when working with live or damaged equipment. Every year there are around 30,000 arc flash incidents that result in 7,000 burn injuries, 2,000 hospitalizations, and 400 deaths. The most frightening thing about arc blasts is that they can heat up to 35,000 degrees Fahrenheit which is more than three times hotter than the sun! While personal protective equipment should be the last resort in protecting oneself from hazards, it is still a needed precaution as arc blasts occur without warning or time for the worker to escape the direct line of fire. Without the proper PPE, the person working on that equipment has the possibility of being severely injured by 3rd degree burns amongst other bodily harm or even killed by the arc blast. Naturally, in these instances, PPE is not only required, but is very welcome for the employee’s sense of self-preservation.

How do I go about choosing the correct PPE?

The first step in picking the right kind of PPE is performing a hazard assessment, as required by OSHA. This helps in determining what kind of PPE employees will be required to use. Standards for arc rated PPE can be found in the NFPA’s 70E standard under article 130.7. There are 4 different categories of clothing that are rated for their Arc Thermal Protective Value, also known as APTV which is measured in calories per centimeter squared. Don’t be fooled, this kind of calorie is not the kind that comes from consuming food, it’s used as measurement of incident energy.

Category 1 is the level that requires protection up to 4 cal/cm2. All the PPE should be fire resistant and arc rated. The list includes:

  • An arc-rated long-sleeved shirt and pants
  • A hard hat with an arc-rated face shield
  • Hearing protection
  • Leather gloves or other insulating material
  • Safety goggles/glasses
  • Leather shoes

Category 2 should protect the wearer up to 8 cal/cm2. It is quite similar to category 1 but should also include a sock balaclava for face protection and have that higher arc flash rating.

Category 3 PPE needs to protect the wearer up to 25 cal/cm2 which is a huge jump in terms of worker exposure to incident energy levels. The wearer needs PPE rated at or above 25cal/cm2, this includes extra PPE such as:

  • Multiple layers of fire-resistant clothing
  • Cotton undergarments
  • An arc-flash suit jacket, pants, and hood

Category 4 is the highest category rating of arc-flash PPE, it requires the minimum rating of 40 cal/cm2, however, the PPE is the same as in category 3 just rated higher. These extreme environments are able to kill workers in less than seconds, they should always be prepared with the correct gear in the case of an accident.

What happens after the correct PPE is chosen?

After identifying the correct PPE that is needed, the employer must provide appropriate training on how to use that PPE in electrically hazardous environments to prevent injury. This often involves discussing PPE requirements during job briefings as well.

The last and one of the most crucial steps needed before putting on arc-rated PPE for a task is performing an inspection on the materials themselves for any sort of damaged or defective equipment. This step can be a life saver, always check to make sure your PPE is in working order before going on the job.

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