Advances in protective systems have contributed to a safer workplace, but even a great safety culture is compromised by the non-use or misuse of safety gear when it is cumbersome or uncomfortable. Nowhere is this truer than in the area of personal protective equipment (PPE). People can always make excuses for not wearing PPE, but there is never a good excuse for not using the right personal protective gear.
Early in my career, I can remember not wanting to wear the chemical safety goggles required for a chemical storage and dispensing area. Was it because I didn’t care about my safety? Was it because I liked to take chances for the thrill of it?
No. It was because the chemical area was on the top floor of the manufacturing plant being baked by the South Carolina sun in August. In the heat and humidity, my goggles quickly fogged up and then eventually held pools of perspiration against my face. I hated them, but I wore them because I didn’t want to be a safety shortcut casualty. Fortunately, safety goggles have come a long way since then, but here’s the point: even the most conscientious workers are tempted to compromise safety when their discomfort level is high.
In the area of FR arc-rated workwear, shortcuts can involve partial exposure, such as when a worker unbuttons his shirt or rolls up his sleeves, to full exposure when the protective shirt is removed completely. The garment cannot protect the worker when it is tied around her waist. Can a flame-resistant arc-rated shirt combine comfort and performance so it does the job and is comfortable enough to be worn â€” properly â€” every time?
Choosing the right protection
Experts in the electrical safety field suggest that workers exposed to electrical workplace hazards should have everyday work clothing with a minimum arc rating of 8.0 cal/cm2 (NFPA 70E®-2009, Annex H). This provides the wearer with clothing for all hazard/risk category (HRC) 1 and HRC 2 tasks, and since this represents daily wear, if you’re dressed for work, you have the basic PPE apparel you need. Then add an arc flash suit or coverall so that the total clothing system has a minimum arc rating of 40 for HRC 3 and 4 tasks. This simplified two-category approach provides increased protection while performing higher risk tasks. When the higher risk tasks are completed, the flash suit or coverall comes off; however the worker is still protected by his or her daily wear clothing.
The comfort factor
At the IEEE Power & Energy Society conference two years ago, I heard a speaker describe the inves- tigation of a case in which an electrical worker was injured because he had rolled up the sleeves of his arcrated uniform shirt. A loose wire in the energized system created an arc flash, and he received second and third degree burns on his arms from his wrists (he wore gloves) to the point where his shirt was rolled up. Why did this experienced electrician compromise a known safety rule? It was hot, and he was uncomfortable. As this incident demonstrates, comfort clearly plays a role in the proper use of PPE, especially in warmer climates where multiple layers are objectionable.
Beat the heat
The body produces heat through metabolic activity, and when working, metabolic activity increases greatly. Some energy is liberated outside the body as work, but most is released into the muscles as heat. Fortunately, heat loss can help balance this thermal load. Heat loss occurs mostly by convection as air flowing across the skin removes heat, and by evaporation of sweat, also known as evaporative cooling. Other avenues of heat loss are conduction, radiation and respiration (breathing). When the rate of heat production of the body exceeds the rate of heat loss, the body stores heat and body temperature rises above normal.
Clothing functions as a barrier to heat and moisture transfer between skin and the environment. It can protect against extreme heat and cold conditions, but at the same time it hampers the loss of extra heat during physical effort. For workers in hot, humid environments, clothing can have adverse effects on the body’s ability to lose heat, making the wearer uncomfortable and possibly contributing to heat-related illness.
According to research at the Human Thermal Environments Laboratory, Loughborough University, UK, thickness is the major determinant of clothing insulation, but for thin materials such as shirting, other factors come into play. Air movement in the work environment is normal and is typically generated by the wind or by the wearer moving around. Depending on the breathability of the fabrics, air pumps in and out as the person works, forcing exchange between the skin and the environment and helping to cool the skin to balance heat production and heat loss. The combination of these factors can be selected to develop protective clothing with optimal comfort.
Fabrics for protective workwear
Determine what you need. If you use the suggested two-category approach, you need FR daily wear with an 8 cal/cm2 arc rating and an arc flash suit or coverall that brings the total arc rating of the system to 40 cal/cm2. Does your clothing also need to comply with the flash fire standard, NFPA 2112-2007? What are your special needs (i.e. rainwear, etc.)? Is a coverall the best option or is a work shirt and pants better?
Once you have made these important decisions, question your suppliers about comfort factors. For workers in hot environments who are wearing long sleeves, it is important to find out the weight of the fabric used in the shirt, pants or coverall. Determine the lowest weight, highest comfort (breathable) garment with the required protection. If you can’t find exactly what you need now, keep looking for new products and innovations. Much is accomplished by those who push the industry for what is really needed. Look for a quality manufacturer with the resources to innovate and keep an eye on what they are doing. While only diligence in the use of proper PPE clothing systems will keep individuals safe, comfort factors play a very important role in making the safe choice.