Page 10 - OHS, June 2021

PPE: PROTECTIVE APPAREL
Understanding the Pros & Cons of PPE When it Comes to the Heat
ThThe summer heat is no joke when it comes to working outdoors; here are facts and tips to stay safe in the blazing sun.
BY MARY PADRON
According to the CDC, “Exposure to extreme heat can result in occupational illnesses and injuries. Heat stress can result in heat stroke, heat exhaustion, heat cramps, or heat rashes. Heat can also increase the risk of injuries in workers as it may result in sweaty palms, fogged-up safety glasses, and dizziness. Burns may also occur as a result of accidental contact with hot surfaces or steam.”
Of the illnesses and injuries spawned by heat stress, heat stroke is the most serious. It occurs when the body can no longer control its temperature. The worker’s temperature will rise rapidly, the sweating mechanism fails and the body is unable to cool down. When heat stroke occurs, the body temperature can rise to 106 degrees Fahrenheit or higher within 10 to 15 minutes. It can cause death or permanent disability if emergency treatment is not given.
If you look at the NIOSH public domain document titled Criteria for a Recommended Standard: Occupational Exposure to Heat and Hot Environments,1 heat stress is a rather complicated and scholarly safety subject with a lot of long words like “thermoanemometers,” equations, symbols and multiple risk factors.
This balance can be disturbed by many risk factors, including: high temperature, humidity, direct sun exposure, indoor radiant heat sources, limited air movement, lack of fluids, physical exertion, advanced age and many more.
Strategies to Reduce Heat Stress in the Workplace
Heat stress can be reduced by modifying one or more of the following factors:
Strategies to reduce the effects of heat in the workplace include eliminating the heat with engineering controls, administrative controls and PPE.
According to NIOSH, environmental heat load, which includes convection, radiation, and evaporation can be modified by engineering controls:
■ ventilation
■ air conditioning
■ screening
■ insulation
■ modification of process or operation
Metabolic heat production can be modified by administrative
controls, such as work practices that limit or modify the duration of exposure time or enhance the heat tolerance of workers through acclimatization. Administrative controls are widely used to mitigate heat stress.
NIOSH suggests four modification strategies for heat stress solutions:
1. modify the work
2. modify the environment
3. modify the worker by heat acclimatization 4. modify the clothing or equipment (PPE)
PPE Can be a “Catch 22” When it Comes to Heat Stress
Let’s take a closer look at personal protective apparel and heat stress. Unfortunately, sometimes PPE contributes to heat stress, especially if a worker is wearing an impermeable encapsulating suit to protect against dangerous chemical splash or viruses. Sweat cannot evaporate, so the worker can’t cool down, which could raise his or her body temperature and heart rate to a possibly dangerous level. Workers who need to wear long pants,
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Occupational Health & Safety | JUNE 2021
www.ohsonline.com
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metabolic heat production heat exchange by convection heat exchange by radiation heat exchange by evaporation