Wearing the right protective fabric can make the difference

For electrical maintenance workers and contractors, working hands-on with hazardous and potentially dangerous energy sources, conductors, circuit parts and other energised parts is a common component of their everyday routine. While there is no substitute for maintaining safe working conditions, accidents - especially electric arcs - can happen in an instant, no matter how experienced a worker may be. 



FR clothing should be standard for any employee working on or near energised electrical systems. This will ensure that workers clothing offers protection from an arc flash exposure rather than producing an additional hazard. The clothing must offer maximum protection while ensuring the worker is comfortable.



There are two main categories of arc flash clothing:

• Primary protective clothing: electrical switching clothing including switching coats, switching hoods and switching leggings.

• Secondary protective clothing: everyday work clothing including shirts, trousers and coveralls.
 







The need for arc flash protection

The intense energy and very short duration of an electric arc flash, reaching temperatures of 19,400 C, can both burn the skin directly and cause ignition of clothing made from regular cotton and poly/cotton fabrics. NFPA 70E, the US Standard for Electrical Safety in the Workplace, states in section 130.7 Personal and Other Protective Equipment (5) Body Protection that employees shall wear flame-resistant (FR) clothing wherever there is a possible exposure to an electric arc flash above the threshold incident energy level for a second degree burn (1.2 cal/cm²). 



Arc exposure energy basics:

• Exposure energy is expressed in cal/cm²
• 1 cal/cm² equals the exposure on the tip of a finger by a cigarette lighter in one second
• An exposure energy of only one or two cal/cm² will cause second degree burns on human skin
• An arc flash event can generate up to 40 cal/cm²
• Up to and exceed 19,400 C, four times Sun temperature

Why flame-resistant (FR) clothing?


People working in any industry wherever there is a possibility of arc flash should wear FR clothing. Essentially, FR clothing saves lives. Importantly, FR clothing does not ignite and continue to burn. Even single-layer FR work clothing can significantly protect employees. 
While most people realise that electrical shock is life threatening, many do not understand that wearing clothing made from regular cotton or poly/cotton that is not FR can result in severe harm or death if it is ignited under an electrical arc flash.

These non-FR fabrics can be readily ignited at some exposure level and will continue to burn, adding to the extent of injury sustained from the arc alone. Most serious burns from industrial accidents are caused by regular work clothing igniting and burning off the wearer's back. Thousands of clothing-related injuries due to fire occur each year. The most severe burns are often not caused by the original hazard. They are the result of the wearer's clothing igniting.