OHS Canada Magazine

Warming To Protective Gear

January 1, 2009

Health & Safety

ON FEBRUARY 3, 1947, the tiny village of Snag in the Yukon set a record yet to be bested. With a week of cold air blowing in from Siberia, Snag netted the lowest air temperature ever recorded in Canad...

ON FEBRUARY 3, 1947, the tiny village of Snag in the Yukon set a record yet to be bested. With a week of cold air blowing in from Siberia, Snag netted the lowest air temperature ever recorded in Canada: -62.8 degrees Celsius.

At that temperature, Environment Canada reports it takes less than two minutes for skin to freeze. Add a mild wind, and the time is halved.

But even at relatively balmy latitudes farther south, working outside during Canada’s winters is no picnic. The Canadian Centre for Occupational Health and Safety (CCOHS) suggests cold can pack quite a wallop: everything from reduced sensitivity and dexterity that impairs manual task performance to stiffened joints and diminished mental alertness.

Fortunately, employers and employees needing to keep warm (and safe) out in the cold have many options to cover them from head to toe.

Body heat


The first thing J. F. Ouelette considers with winter wear is “what kind of energy you’re going to be using up during your work.” Elaborating, the product manager for North Safety Products in Montreal says, “if you’re basically on the side of the road, and you’re holding up a stop sign to control traffic, you better have gear that’s going to have a higher level of warmth than if you’re with a shovel digging a hole.”

But few jobs demand the same level of exertion throughout the entire workday. And this is where layering may become a worker’s good and useful friend. “You have to have a certain flexibility in terms of removing the layers of garments based on the amount of heat you’re generating,” says Ouelette.

Regardless of exertion level, he recommends that winter jackets have some kind of polyester fill, which comes in a range of weights. “Polyester has this big advantage that it’s all full of air bubbles,” Ouelette says, and once warmed by body heat, those bubbles help insulate the wearer from the cold outside.

Of course, there’s a limit to how much polyester you can stuff into a jacket. “You need to walk around; you need to lift your arms,” Ouelette quips, so some trade-off between warmth and mobility is the norm.

The outside of a winter jacket is equally important. If the job in question involves hazards like flash fires or arc flashes, Ouelette says the shell of a jacket will need to be made from flame-resistant woven synthet- ic fabrics; high-visibility, possibly fluorescent, woven polyester for road workers; and a woven cotton/polyester blend for general outside work. All of these woven fabrics can be chemically treated to make them more water-repellent, he notes.

Wind talker

Just how woven materials react to the elements — say, the wind — can also be seen as a trade-off. The looser the weave, says Ouelette, the less resistant to wind. In fact, a loose weave will allow an errant gust to carry with it all that insulating air a body has built up.

But too tight is no better. “If you have a weave that is extremely tight, then you might have problems in terms of dissipating moisture,” says Ouelette. And once too much moisture builds up inside a jacket, a cold feeling is sure to follow.

The solution may come from garments that have undergone considerable research and are no stranger to sweat: sportswear. Microporous films initially developed for athletic gear have two key properties: they act as a barrier to wind, and they release moisture at a controlled rate.

By having a micro-porous material between a jacket’s shell and lining, Ouelette says the wind resistance of a relatively loose-weave shell can be increased while preserving some of its moisture dissipation.

Again, there is a limit to how much moisture can be released. Physical work will cause moisture buildup inside a garment eventually, he says. It is then that a wearer will appreciate two-way zippers and vents.

Hand in glove

No matter how warm the jacket, a person won’t get any work done if his or her hands are, well, too cold to get any work done. And that demands gloves suitable for the weather and the task at hand.

Joe Geng, vice-president of Superior Glove Works Ltd. in Acton, Ontario, says “you want to go with the most comfortable and dexterous glove that the temperature will allow.” Geng’s point illustrates yet another trade-off in winter wear: the colder the conditions, the less dexterity one can expect gloves to have.

At warmer temperatures, from 10 C above to five C below, Geng recommends a Terry-knit glove with a latex-coated palm. The knit provides adequate protection from the cold, while the coating offers good water repellence and grip in both wet and dry conditions.

Once temperature dips below -10 C, Geng says that coating on gloves — whether latex, nitrile or poly- vinyl chloride (PVC) — begins to stiffen and grip becomes markedly diminished.

In these colder conditions, an alternative may be to go with either a heavily insulated leather glove or a well-insulated synthetic glove.

Leather has proven a popular choice for work in the cold, offering as it does great grip at any temperature, comfort and durability, but little water repellence and insulation. Coated nitrile, latex and PVC count great dry grip, dexterity and water repellence among their welcome features, but have poor wet grip and stiffness below -10 C.

Understanding that each material has its benefits, one offering from Superior Glove represents a veritable team effort: the palms are made from synthetic leather; there are several patches of anti-slip PVC; the back is a nylon/lycra blend, for comfort and dexterity; and the knuckle strap is made out of Kevlar and stainless steel.

As the outside air dips under -20 C, however, it’s time to reach for the mitts, Geng suggests. “Mittens are warmer because they allow for air circulation, preventing a small isolated area, say a finger tip, from getting extremely cold.”

For example, his company has mitts with a calf-skin outer layer and a four-layer removable liner: two layers of foam-to-fleece laminate surrounding two layers of Thinsulate.

Still, the best glove in the world won’t do its job properly if it doesn’t fit well, says Michael Everett, general manager of Best Glove Inc. in Coaticook, Quebec. “If you start wearing a glove that’s too tight, the cold transfers pretty quickly through the glove,” Everett says. He makes the following observations:

• for workers dealing with liquid propane, a neoprene-coated glove will offer chemical protection and doesn’t crack “quite as easily” in the cold as some PVC gloves;

• a nitrile glove “stands up better to oils and fuel oil than other gloves,” but will also grow stiff in the cold; and,

• nitrile-coated gloves with safety cuffs, which can be easily removed, have proven popular among fuel oil handlers.

Everett’s company offers one glove coating specifically formulated to maintain flexibility in cold weather, but the drawback of these and similar gloves is that they don’t “stand up very long in harsh chemicals.”

Echoing Ouelette, Everett agrees there are trade-offs. “If you want the protection from the chemical, then you need a heavier-weight glove. And as soon as you get to heavier-weight gloves, you lose a lot of the flexibility [in the cold].”

Companies, however, are working to lessen that trade-off. Best Glove makes a seamless acrylic-blend liner, dipped in natural rubber, that offers plenty of warmth while retaining more flexibility than synthetic-coated gloves, Everett says.

Superior Glove, Geng says, sells nylon gloves coated in specially formulated PVC, which allows greater flexibility.

Kick It New School

Keeping hands warm is clearly important to ensure workers maintain a firm grasp on workplace demands. But what about extremities due south? Having cold feet is, at best, distracting and, at worst, dangerous. The CCOHS advises insulating the legs by wearing “dancercise-type” warmers, insulating overshoes over work footwear, and insulating muffs around the ankles and over
the top of the footwear.

The top footwear pick for heavy work in the cold is likely felt-lined, rubber-bottomed, leather-topped boots with removable felt insoles, the CCOHS notes. But if work involves standing in water or slush, waterproof boots are in order.

For workers needing exceptional waterproofing, Chris Ransome, vice-president of marketing for Simcoe, Ontario-based Ranpro Inc., notes that there are polyurethane foam boots manufactured using rapid injection molding.

“As the material is injected into the mold,” Ransome says, “it expands and traps millions of microscopic air bubbles in the compound, thus making the boot very lightweight, very flexible, and giving it an extreme degree of thermal regulation.”

The air bubbles act much like the air in a polyester coat lining. “There’s absolutely no liner in this boot. It all comes from the material itself,” Ransome adds.

In addition to being rated for near-Snag temperatures, he reports that the boot will last three to five times longer than a PVC or rubber boot.

Ransome notes these boots have found a home in fishing, construction, oil and gas, food processing and freezer applications.

Head start

Cold affects workers up and down — and that’s key to bear in mind. The CCOHS cautions that “almost 50 per cent of body heat is lost through the head.”

That makes outfitting a worker with properly insulating headgear particularly important. (Of course, your mom could have told you the same thing.)

And while choosing the right touque may be second nature for Canadian workers, those donning a hard hat when working in the cold have options as well. Claudio Dente, president of Dentec Safety Specialists Inc. in Newmarket, Ontario, says that a wide variety of hard hat liners are available to trap escaping heat.

At the most “cost effective” end are inserts with a quilted shell and flannel liner, says Dente. A little warmer are 100 per cent cotton shells, with a flannel liner,that cover the neck. For those wanting a “very thin, very soft, very warm” liner, he points to a polar fleece option with a detachable facemask.

Inside Out

While most winter gear works to keep workers protected from outside elements, Dentec Safety offers warmers that take a different tack. One of these is a powder that is dissolved in warm or hot water — an alternative to drinking the more standard “double-double,” Dente suggests.

And that’s good. Coffee, along with tea and some hot chocolate, contains caffeine, a diuretic. “What they basically do is restrict the flow of blood to the extremities,” he says.

The powder solution “leads to better circulation,” Dente says, by rehydrating and replacing electrolytes that may have been lost. And better circulation helps keep a person warm.

Then there are warming packs that can supplement the body’s natural heat generation capacity. Air-activated and made from natural ingredients, these heating options can be slipped into gloves, jackets, vests, boots and even hard hat liners, and last up to 18 hours.

Heat Factory recently announced the availability of its heated neck gator, which is double-lined and made of extra-thick fleece. The gear has warmer pockets strategically placed over the ears, neck and chest.

The company also offers heated helmet balaclavas, the breathable fleece and streamlined shape of which hugs the head to allow any type of helmet to be worn over top.

Sometimes, however, a bit of battery power will quickly ramp up warmth. Options in this vein include gloves — fully lined with Thinsulate, with non-slip palm and finger surfaces and barrel cord adjustment on the cuffs — that offer eight hours of warmth on just one battery.

Knitted socks also get cozy from a battery pack that generates safe heat to an embedded coil. Dual temperature settings allow the wearer to control just how much warmth is needed for as long as 12 hours on one alkaline “D” battery.

View from here

Looking forward, Everett expects seamless gloves and liners will gain profile since their form-fitting nature helps support worker comfort. “The seamless acrylic liner seems to be the new technology.”

For his part, Ouelette sees ergonomic and comfort issues becoming more central to the design of winter wear. Parkas, gloves, boots and hats “should be considered, up to a certain point, personal protective equipment,” he suggests. As such, Ouelette recommends that employers take more care in evaluating workers’ cold weather needs when buying gear.

“Instead of saying, ‘Here’s your winter parka, Bob. Use it for the year,’ they should take a step back and say, ‘We want to outfit our people,'” he says. “At minus 30, there is a risk to life.”

Of course, for little Snag, -30 C is a day at the beach.

By Andrew D’cruz

Andrew D’Cruz Is Editorial Assistant Of OHS CANADA.


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