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Keeping Cool on the Job with Appropriate FR Attire


 April 2015    

Keeping Cool on the Job with Appropriate FR Attire

By: Cortlandt Minnich, Business Development, TECGEN® Brand

Regulating body temperature in extreme temperatures can be challenging under even the most normal circumstances. However, situations in the oil and gas industry requiring flame resistant (FR) garments can create extra obstacles due to the natural insulation properties of FR clothing. When developing an FR garment program for hot environments, special considerations must be taken to keep workers as safe and comfortable as possible on the job.

Challenges Associated with Extreme Heat
Heat stress is commonly experienced by workers exposed to extreme heat and can result in heat stroke, heat exhaustion, heat cramps or heat rashes1 . In fact, the U.S. Bureau of Labor Statistics (BLS) reports that ‘Exposure to Environmental Heat’ caused 177 deaths and 13,580 cases of days away from work in the private sector workforce2 from 2003 – 2008.

Matching the right fabric technology and the appropriate insulation level to the daily
tasks of a worker is critical. 
CREDIT: TECGEN® Brand FR Garments

While heat stress can be attributed to external factors like temperature, other factors such as workplace uniforms can also contribute to the impact of these sources of heat. A worker may not consciously realize the effect of his or her garments on core body temperature. This is why choosing the right clothing is a key factor in regulating temperature while working in a physical role – just like for exercising. Considering how the company uniform can affect a worker’s thermal comfort is essential when evaluating and specifying flame resistant garments.

Total Heat Loss: A Key Measurement for Evaluating FR
Total heat loss (THL) is a method that measures the maximum workload or metabolic activity rate a person can sustain while maintaining thermal comfort in personal protective equipment (PPE). This measure is part of the certification for garments in the fire-fighting industry. THL measures the amount of conductive (dry) and evaporative (wet) heat loss that occurs through the fabric of a PPE garment3. By placing fabric samples on specially designed plates that simulate hot, sweaty skin under controlled lab conditions, the ability of the fabric to transfer heat can be precisely measured. In hot conditions, a fabric that holds less heat is more desirable to allow excess heat to move away from the body.

Selecting the Right FR Garments for Hot Environments
In hot environments, choosing garments with high THL performance is important for employees as well as management. Employees in physical roles may face discomfort, physiological strain, decreased productivity and performance, and potentially increased accident rates on the job4. A uniform with better performance can have some level of impact on these challenges.

THL combines the performance of several fabric properties, including air permeability and moisture wicking:

• Air permeability is a key contributing factor to good THL performance. Certain PPE garments have a low air permeability rate, which limits evaporation and normal heat dissipation through airflow. This in turn increases body temperature and sweating5.
• Retaining moisture reduces a fabric’s THL rating because it decreases the evaporative cooling capability. So, the same cotton that feels comfortable around the house becomes a liability in an extremely hot work environment. For example, cotton shirts are soft and comfortable in moderate temperatures, but when exposed to increased levels of sweat, they become saturated and can cause discomfort.

The natural reaction to facing a hot environment in heavy clothing is to make modifications to the prescribed equipment – affecting its intended purpose. Rolling up the sleeves or leaving a coverall unzipped are common modifications that unravel FR safety protocols, and in some cases may add the risk of entanglements.

From Safety Managers to Employees
By selecting FR garments with THL measures in mind, safety managers can take steps to ensure employees will remain safe and comfortable in the workplace. In addition to preventing accidents, selecting the right FR garment can help increase productivity as workers may require fewer, shorter breaks and time-off related to heat stress issues6.

Lowering heat stress should be considered an important part of managing safety in a warmer workplace. By specifying garments that are lightweight, breathable and moisture wicking, safety managers can help prevent heat-related accidents and injuries.

In addition to specifying optimal garments for hot environments, safety managers should take the initiative to educate employees on selecting the right undergarments, should they provide their own.

The Bigger Picture
When evaluating uniform choices, specifiers should consider how each outfit will affect worker safety and comfort level, which can have an impact on overall productivity. Each garment should be assessed not only in terms of breathability, but moisture-wicking ability and weight as well. Finally, the more employees can customize their personal uniform using garment layers, the better the chances they will remain compliant.

Cortlandt Minnich is the New Business Development Director for TECGEN® FR at INVISTA. TECGEN® FR garments are a lightweight and breathable alternative to legacy FR garments. Coveralls, shirts and trousers are dual-certified and designed to withstand demanding work environments while delivering a comfortable, moisture-wicking fabric solution. Visit for more information.


1Center for Disease Control 
2Bureau of Labor Statistics 
3Fire Engineering 
4Extreme Physiology & Medicine
5Extreme Physiology & Medicine
6Extreme Physiology & Medicine



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