It's funny to see sportscasters drool all over themselves when athletes play in inclement weather. The players are called "warriors" as they "fight the elements!" These grown men playing children's games for ludicrous money don't impress me all that much. That's because I've never seen Ben Roethlisberger work on a rig during a lightning storm, let alone climb a swaying wooden utility pole to repair live overhead power lines.
Industrial workers are charged with accomplishing some of the most difficult tasks in the most inclement weather in dangerous environments. Just as you wouldn't see a professional athlete take the field without his personal protective equipment (PPE), it's equally important that industrial workers come to the job site dressed properly, particularly as winter descends upon the country.
Comfort Is Key to Compliance
Managing body temperature is important in any work environment, but extreme cold brings unique challenges. Workers need to remain mobile and capable of performing small and large tasks, so the proper layering of clothing is critical. If not done properly, the work environment quickly can become uncomfortable and even intolerable.
Clothing system comfort during cold weather is influenced by a number of factors such as: environmental conditions (i.e. temperature, precipitation, wind); level of physical exertion required for the task at hand; age; and the physical condition of the individual. When choosing a clothing system, all these factors must be considered as well as the nature of the specific tasks the worker must complete.
EHS professionals also must consider the potential change in environmental conditions that can happen during a typical day. For example, it may be below freezing in the morning but reach a more pleasant temperature by midday. To adjust for major swings in conditions, and to prepare for days in winter when working in the cold all day is expected, wearing or having a high performance FR clothing layering system is important.
A successful clothing system allows for layers that can be added or removed to adjust to the external environment while still providing adequate protection from the flash fire or arc flash hazards associated with the job.
An FR layering system should be viewed as a required tool for the job and is no different or less important than any other tools or PPE used by the industrial athlete. EHS professionals face the added challenge of determining what garments are needed within an approved clothing line that will account for all the differences in the workforce itself and the varying environmental conditions they may experience on the job.
Comfortable clothing systems help ensure PPE compliance – workers wearing the amount of clothing necessary to protect them from flash fire or arc flash hazards – and they may be more productive due to reduced fatigue and the ability to focus on the task at hand rather than stopping work due to comfort issues caused by improper clothing choices.
Simply stated, a full cold weather layering system can be defined by three clothing elements, each with a specific and interrelated role to perform within the system: garments for the base layer, insulation and weather protection.
All About That Base (Layer)
The base layer, or garment that sits on the worker's skin, supports all the other clothes in a layering system. There are three defining factors for the base layer performance that are essential to comfort: moisture management, breathability and tactile (hand) feel.
Just because a garment says it wicks away moisture does not mean workers immediately should buy it. Many fabrics absorb moisture from the skin but some are more suitable for cold climates than others. For instance, an FR cotton T-shirt will wick away sweat but also can hold moisture, which can make a wearer feel cold once the person stops moving.
Rather than wicking, industrial athletes should look for garments not only capable of wicking but also transporting moisture through the fabric to the surface where it can move to the next clothing layer or quickly dry without the garment becoming fully saturated with sweat. Workers looking for this tri-dynamic effect should look for garments that use hydrophobic (water-hating) fibers in conjunction with hydrophilic (water-loving) fibers in the right combination as a base layer fabric. Note that in hot weather the base layer may be the only layer worn and similar moisture management characteristics are desirable for FR clothing worn next to skin.
As mentioned, fabric breathability also is critical for the base layer as air exchange within the clothing system helps facilitate quick drying. In regards to arc flash safety, results from a study published by Hugh Hoagland , "Study of Effects of Mining Industry Contaminants on Protective Properties of Arc Rated Clothing, January 2012," found that FR fabrics saturated with moisture lost nearly 50 percent of their FR arc-rating protection when tested while wet. With this in mind, keeping the worker dry also is a critical component of keeping them safe.
The tactile or hand feel of the fabric, while seemingly basic – "If it feels good I will wear it" – is extremely important in keeping industrial athletes compliant. FR garment brands have made great strides in creating workwear that feels and looks good while still satisfying recognized FR safety compliance standards. Protective clothing workers like and want to wear is the surest way to achieve safety, even when nobody is watching.
The Goldilocks Effect of a Good Insulation Layer
Insulation is the mid-layer of the cold weather clothing system designed for two key purposes: keeping the industrial athlete warm while he is working and maintaining body temperature equilibrium during rest.
A common complaint is that it can be difficult to find proper insulation layers that achieve this "Goldilocks Effect," but there are two key things you should look for when selecting a mid-layer garment:
Breathability of the garment is important for a mid-layer just as it is for a base layer. In order to maintain core body temperature equilibrium, a mid-layer must have good breathability so that heat and moisture vapor can pass through the garment. Even during cold weather, a worker will generate a lot of heat and body moisture when active.
Garment thickness (though weight doesn't necessarily equal warmth) also is very important as it relates to the "clo value" of the garment. The clo value is a unit of measure used to describe the warmth offered by a specific fabric.
The clo value uses the same R-value system in residential construction to measure insulation value. A clo value of 1.0 (0.88R) describes the amount of insulation that allows a person at rest to maintain thermal equilibrium in an environment at 70°F in a normally ventilated room. Look for thicker, preferably lighter mid-layers when building your winter clothing system. Single- or double-sided fleece fabrics are known for their high warmth-to-weight performance, for example.
Stretch also is important in an insulation layer just as it is for a base layer. Garment stretch allows freedom of movement for the industrial athlete while he is at work and this dynamic is critical for a multi-layer clothing system. When multiple layers of clothing are worn, they must work together with each layer, having performance characteristics that work in harmony with the others. If not, these layers of clothing will cause immobility and discomfort.
Shielded from the Elements
The weather protection layer, often called outerwear, is the lynchpin that brings together the layering system. It is the layer responsible for environmental protection as well as the most visible part of the system. As much as tough industrial athletes don't want to admit it, fashion is an important variable in ensuring compliance. EHS professionals can feel more confident their teams will be wearing their FR clothing when working if their FR workwear looks good.
External work environment conditions vary with the weather and the temperature swings that are common during the winter season. For this reason, more than one outerwear piece may be required for the industrial athlete. Here are some tips on how to choose an outerwear layer:
Look for outerwear garments that fit the conditions (provide comfort and protection) likely to be experienced on "game day."
Will there be any contact with snow or cold rain? If the situation involves possible precipitation and a rain slicker is not appropriate, look for outwear garments that offer water repellency. This fabric feature – known as DWR (durable water repellency) – is created by bonding a safe, hydrophobic chemical to the fabric. DWR fabrics also make it easier to launder soils and stains out.
Breathability again is important for this garment layer, but at a lower level so that the wearer is protected from wind. Garment breathability can be measured by a standardized test that measures air permeability (ASTM D737). Industrial athletes always should ask for the air perm rating when purchasing FR garments. A rating of zero cfm (cubic feet per minute of air passing through the sample tested) would denote no breathability, like a rain slicker. Breathability of 80-200 cfm would be common for a mid-layer insulation garment with good breathability, and a jacket with a cfm rating between 2-20 cfm would offer both wind resistance and breathability.
Industrial athletes must be properly equipped in order to do their best work. EHS professionals' best efforts can be undermined if workers' clothing does not offer proper weather protection and properly maintain worker comfort as the environment and physical activity levels change throughout the day on the job.
Winter is coming, so it's more important than ever for industrial athletes to use a highly technical layering system that facilitates – rather than eliminates – comfort and safety.
Michael Batson is the product management director of workwear and military at Polartec. His career focus has been in high-performance technical fabrics, and he has led the charge to create new businesses that specialize in making protective and flame-resistant apparel fabrics for the past 10 years.