An arc flash can easily be deemed as one of the most hazardous events to occur within a workplace. However, despite constant care and maintenance of electrical tools, an arc flash can still occur with basically no warning at all. Even though arc flashes may be relatively rare, they are still possible and employees need to exercise constant caution when working with or around electrical equipment.
What are the Guidelines?
As a result of various injuries and deaths stemming from arc flashes, there have been various changes incorporated into the NFPA (National Fire Protection Association) 70E, with the most recent version being published in 2012. While it is important to utilize the assistance of PPE when working with or around electrical equipment, it is also important to remember that PPE is actually the last form of defense when up against the possibility of an arc flash.
The NFPA section 130.7 (A) states “Employees working in areas where there are electric hazards shall be provided with, and shall use, protective equipment that is designed and constructed for the specific part of the body to be protected and for the work to be performed.”
Hazards of Arc Flash
The hazards associated with arc flash are often catastrophic in nature and may lead to irreversible injuries and even death. To this into perspective consider this example, the surface of the sun is somewhere around 9000 degrees Fahrenheit, while the temperature at the arc terminal can easily reach temperatures of 35,000 degrees Fahrenheit. This means that the temperature of an arc flash can be nearly four times hotter than the sun. The heat is almost unimaginable. Just think back to the last time you accidentally burnt your hand on a stove or in the oven and how bad it hurt, and to think that it was probably only a few hundred degrees.
Even though many people focus primarily on the hazards associated with the heat of an arc flash, there are also many hazards associated with the inhalation of fire smoke caused by an arc flash. There are more than a hundred toxic substances contained in this smoke, and when you combine high levels of smoke inhalation with burn injuries the risk for death after an arc flash skyrockets.
Correct protective clothing or PPE should be chosen based upon the NFPA’s corresponding hazard risk category. For example, if you are in a HRC (hazard risk category) 1, FR shirt, FR pants, or FR coveralls should be worn. However, if you are in a HRC 4, cotton underwear combined with FR pants and a FR shirt along with a multilayer flash suit must be worn. These PPE guidelines are based on general work settings and involve no field data.
The NFPA 70E 2012 edition should be an integral piece of safety information utilized in any workplace that harbors the risk for an arc flash. Take the time to understand and become familiar with the guidelines and safety information related to electrical safety and arc flash so both you and your employees are adequately protected.