Those who work in the electrical industry know the dangers that come with their job. On a daily basis, these workers place themselves in the line of danger while repairing blown transformers, replacing downed power lines and handling other jobs where high voltage is a constant threat. Thankfully, there is electrical safety clothing which can help reduce the chance of long-term injury or death.
Electrical safety clothing, or sometimes called arc flash clothing, serves as a protective barrier from heat and flame for those who wear it. It is designed to minimize injury and give the wearer a few extra seconds to seek shelter from a potential explosion or fire.
Workers who wear the proper electrical safety clothing have a higher chance of surviving an electrical arc event.
When an electrical arc accident occurs, the heat is can cause tremendous damage. Without safety electrical clothing, any synthetic fibers, like nylon, would immediately melt onto the worker's skin, causing intense burning, severe skin damage and possibly death. Additionally, clothing like jeans, cotton t-shirts, sweatshirts and other normal-wear clothing can also serve as fuel for the fire.
To be fully protected from an arc blast, the worker should be wearing NFPA-approved heat retardant clothing with an ATPV* rating of no less than four.
*ATPV stands for Arc Thermal Perfomance Value, which rates the maximum capacity for arc protection of a certain piece of clothing. ATPV is presented in calories per square centimeter (cal/cm2).
Depending on the type of work being performed, a worker should choose the appropriately rated clothing. To help make this easier, the NFPA assigns a zero to four rating number which represents the level of danger should an accident occur. Here is how the designations are identified:
If the NFPA 70e Hazard/Risk category is 1, then the ATPV rating is equal or greater than 4. This type of risk requires electrical protective clothing to have an FR Garment Level of 5 cal/sq.cm.
If the NFPA 70e Hazard/Risk category is 2, then the ATPV rating is equal or greater than 8. This type of risk requires electrical protective clothing to have an FR Garment Level of 8 cal/sq.cm.
If the NFPA 70e Hazard/Risk category is 3, then the ATPV rating is equal or greater than 25. This type of risk requires electrical protective clothing to have an FR Garment Level of 25 cal/sq.cm.
If the NFPA 70e Hazard/Risk category is 4, then the ATPV rating is equal or greater than 40. This type of risk requires electrical protective clothing to have an FR Garment Level of 40 cal/sq.cm.
Electrical protection clothing is made to protect virtually every part of the human body. A complete outfit consists of electrical protective shirt and pants, insulated leather footwear, insulated rubber gloves with leather protectors, face shield, flame resistant head gear, flame resistant neck protection, ear and hearing protection and the protective outer suit.
Also important for electrical protective clothing is its HAF rating. HAF stands for Heat Attenuation Factor. This rating is important because although a particular piece of clothing may be considered flame resistant, it is not always HEAT resistant. This rating indicates the percentage of heat capable of being blocked by the clothing. Here's an example: if the clothing has an HAF rating of 75, then 75 percent of the heat will be blocked by the clothing.
Many workers have a false sense of security when outfitted in electrical protective clothing. This can actually place them at greater risk of experiencing an arc blast. It is important to always respect the electricity you are working with. The clothing can sometimes be thick and cumbersome, causing a simple repair to take much longer than you would think. Because of this, many people lose sight of the safety aspect and experience a dangerous episode.
Electrical protective clothing is just one piece of an overall safety measure.