Workplace Solutions Protective clothing Seasonal safety: Winter

Cold weather safety

What advice can safety managers share with workers about layering clothing appropriately so that they do not feel too cold or hot in the field? What fabric qualities should we look for when specifying FR garments for layering in cold weather?

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Responding is Cortlandt Minnich, TECGEN Brand business development, TECGEN FR Garments, Greenville, SC.

Dressing to work in cold weather can be more complex than putting on a heavy coat and heading out to the site.

Workers in cold environments must pay special attention to factors that affect not only their sense of comfort, but their safety as well. These factors include the temperature and humidity of the environment; the level of physical activity; wind; break cycles; and their size, weight and physical condition.

A worker performing low levels of physical activity in cold temperatures can increase personal comfort simply by adding additional insulation over the entire body. This can be done in a heavy single layer or in multiple thinner layers.

A body in motion provides a much bigger challenge. In colder temperatures, a body will burn calories not only to do work, but also to regulate body temperature. The body has a network of sensors that keep close track of temperature, so any area of the body that overheats gets the signal to cool by sweating. This moisture is one of the biggest challenges for comfort in a winter clothing system. Removal via evaporation should be minimized because it creates cooling, but collecting moisture under heavy clothing is also problematic because it can leave a worker feeling soggy and wet.

Matching the right fabric technology and the appropriate insulation level to a worker’s daily tasks is critical. Too much insulation will cause overheating. And, fabric that retains moisture in this layer system will lose its insulative quality and expose a worker to colder moisture against the skin. This is why many outdoor enthusiasts say “cotton kills.” Layers are customary for these outdoor athletes because they can be removed or added to meet very precise conditions. A session of hard work can be done in two layers to minimize overheating and sweating, and then a cool-down period can be performed with an additional layer added on top. Two crew members who are at the same site working side by side may need completely different uniform systems based on their activity, role, work cycle and even their physical build. Over time, workers also acclimate to their environments and physical activity levels and may need to adjust their clothing accordingly.

Focus on FR

Insulation is an important aspect of winter workwear, and moisture management is critical for workers in motion. In the oil and gas, electrical and manufacturing industries, special attention must be paid to FR protection and compliance with 2112 and 70E, particularly in winter. Garments that are not FR – especially heavyweight versions – are actually additional fuel. Wearing a non-FR hoodie underneath an FR shirt will add a comfort layer, but the exposed non-FR hood is dangerous and non-compliant with FR standards.

Additionally, many non-FR winter base-layers are made from Polypropylene and blends that contain Polyester. Both of these materials have low melting points and can lead to tragic injuries if exposed to a thermal incident. Section 130.7 (C) 9 of NFPA 70E states: “Meltable fibers such as acetate, nylon, polyester, polypropylene, and spandex shall not be permitted in fabric underlayers (underwear) next to the skin.”

When developing your winter weather uniform choices, consider garments that perform well in layered configurations. The more your employees can customize their personal uniform using layers, the more likely they will remain compliant even when unsupervised.

Editor's note: This article represents the independent views of the author and should not be construed as a National Safety Council endorsement.

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