Arc blast and arc flash are among the most dangerous hazards that electrical workers face. Electrical arcs can reach extremely high temperatures and can be hotter than the surface of the sun for a short period. Arc blast and arc flash can also create immense pressure and emit hot gases and molten shrapnel causing injuries ranging from minor to extremely serious. What the victim is wearing at the time of the incident largely dictates the severity of the injury.
It is paramount that workers wear and care for appropriate flame-resistant (FR) clothing. OSHA CFR 1910.269(l)(6) requires that workers are trained and familiar with the dangers associated with electric arcs and the fires they can ignite. OSHA prohibits workers from wearing clothing that, in the presence of an arc, can increase the severity of injury, e.g., igniting, continuing to burn or melting on the skin. As a result, workers are not allowed to wear clothing made entirely of, or blended with, synthetic materials such as acetate, nylon, polyester or rayon.
According to the OSHA eTool, “Electric Power Generation, Transmission, and Distribution: Personal Protective Equipment (PPE)—FR Clothing,” when selecting the appropriate FR attire, “Clothing made from 100% cotton or wool may be acceptable if its weight is appropriate for the flame and electric arc conditions to which a worker could be exposed. As heat levels increase, these materials will not melt, but they can ignite and continue to burn. The amount of heat required to ignite these materials is dependent upon a number of factors, including the weight, texture, weave, and color of the material.”
Employers must ensure workers’ clothing is acceptable under the conditions to which they could be exposed.
Cleaning FR garments
FR clothing can be worn to prevent serious injury. However, it must be properly cared for to ensure it can protect workers. Workers must be familiar with the manufacturer’s cleaning recommendations.
If using an industrial laundry service, it is imperative that all FR garments are washed separately in soft water (less than 4.0 grains). Hard water contains mineral salts that can compromise the clothing’s integrity.
Nonionic formulas are typically the most effective cleaning solutions for this type of clothing. Never use natural soaps or chlorine bleach. If the clothing is heavily soiled with particles or abrasive dirt, it can be flushed with water at a temperature of 105°F at the start of the cycle. This will help minimize abrasion in the wash wheel.
When drying FR clothing, the dryer’s temperature should never exceed 280°F. Do not use starch. Fabric softeners should never be used because they can accumulate between fibers and be flammable. Garments that need to be pressed should be done so at temperatures less than 280°F.
If a worker cleans their FR clothing at home, they should turn it inside out, and each article should be washed separately in a normal or cotton cycle at any water temperature up to 140°F. Most home laundry detergents are fine to use. However, avoid tallow soaps that may contain animal fats, since they can be flammable and accumulate in between the fibers. Using conditioned or soft water can help improve removal of contaminants from FR clothing.
When garments are soiled, it is important that dirt and other contaminants are completely removed. Stain-removal products or presoaking garments are acceptable.
If articles cannot be completely cleaned at home, they can be sent to the dry cleaner. Employers and employees should also be familiar with the manufacturer’s instructions for dry cleaning. Whenever FR clothing becomes contaminated with flammable substances, it must be removed immediately and swapped out for uncontaminated FR apparel. Garments should be discarded if the flammable material cannot successfully be removed.
Repair and maintenance
Finally, the American Society for Testing and Materials International has two standards that address the repair and maintenance of FR garments. Standard F 1449: “Guide for Industrial Laundering of Flame, Thermal and Arc Resistant Clothing” and Standard F 2757: “Guide for Home Laundering Care and Maintenance of Flame, Thermal and Arc Resistant Clothing” provide information for home care and maintenance of FR garments. These standards—which employers and employees should be familiar with—indicate that all FR clothing repairs should be made with materials equivalent to the original clothing materials.
If you would like more information on the importance of FR clothing and how to properly clean, care and maintain it, visit www.osha.gov.
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