Boots Should Be Safe, Comfortable

Work boots go through rigorous testing before they go on the market

By Aram Kalousdian, editor, Michigan Contractor & Builder -- Associated Construction Publications, 11/19/2008

W.L. Gore & Associates tests everything from the shoe’s leather and foam to the stitching and laces to determine how much water they absorb. Materials used in the shaft must be water repellent or they could carry water to other parts of the shoe.

"These boots are made for walking, and that’s just what they’ll do / One of these days these boots are gonna walk all over you" (lyrics from a song by Nancy Sinatra) … and if you don’t pay attention to the boots you wear on the job site, your boots will walk all over you.

Work boots are such an important part of a construction worker’s attire that the Occupational Safety and Health Administration (OSHA) has regulations regarding what is worn on our feet in a construction work zone. Work shoes must provide safety first and foremost; they must protect your feet while on the job and they need to be comfortable.

"It’s important to buy a boot that has a good fit and good support in it," Mark Cirino, product specialist for W.L. Gore & Associates, said. "It’s very easy to not want to spend the money on your boots, but you should consider them as a set of tools. Remember, your feet are in them all day long. Even though it is difficult to correlate, there probably is some relationship with productivity.

"A boot that doesn’t fit well, over time, will hurt your feet, and when you get older, you will potentially have some issues."

W.L. Gore & Associates uses science-based research and testing to create the GORE-TEX waterproof, breathable lining that goes into numerous brands of work boots including Danner, Red Wing, Rocky, and Wolverine. Several equipment manufacturers offer privately branded work shoes as well; for example, Cat calls its company-branded boots "Walking Machines."

W.L. Gore & Associates tests GORE-TEX footwear for breathability and climate comfort. Artificial feet that sweat like real ones are put into the boots and then placed in a climatic chamber to measure water vapor that escapes and water retention levels at various temperatures.

What kind of research and testing does Gore do? The company tests for breathability and climate comfort by using engineered forms and artificial feet that react to climate and environmental changes. They really sweat just like your feet do. The engineered forms are used for the Breathability Test; they sweat moisture and vapor. This form consists of one of W.L. Gore & Associates’ micro-porous membranes that sweat like human skin. W.L. Gore & Associates makes these specially engineered forms. The Breathability Testers are modular, so W.L. Gore & Associates can run as many testers as they need, depending on how many tests they need to get done. The boot is placed over the test form that is equipped with microprocessor-based controls that govern the amount of water vapor inside the boot. This test is carried out in a climate-controlled laboratory. W.L. Gore & Associates analyzes the Breathability Test results to determine if the boots will provide the right amount of climate comfort for workers. Standards are set for the amount of moisture vapor that the boot must transmit. These standards have been derived from W.L. Gore & Associates’ extensive studies and trials on climate comfort that they have done in the field and in the laboratory.

The artificial feet are put into the boots and then subjected to changing climatic conditions. This is called the Flexor Test, in which the boot is placed in water and mechanically flexed to simulate walking in wet conditions. These mechanical feet take a hike and take up to 300,000 steps in a water bath. This is equivalent to spending approximately 40 hours working on a soggy job site. Yuk! The artificial feet have electronic sensors built into them that will indicate when water had made its way into the inside of the boot. When this happens, an LED light indicates which sensor was triggered. The boot is lifted out of the water, and the test is stopped. W.L. Gore & Associates tests everything from the shoe’s leather and foam to the stitching and laces to determine how much water they absorb.

W.L. Gore & Associates places boots on flexible artificial feet equipped with sensors that take up to 300,000 steps in a water bath. If moisture enters the shoe, the machine stops and an LED indicates the location of the leak.

The GORE-TEX membrane stops water from going through the boot. However, if the upper material in the shaft of the boot is not water repellant, it could wick water up the shaft of the boot, over the top and into the boot.

"If you have wet socks and wet feet and you’re out there working, you’re going to damage your skin and your feet," Cirino said. To avoid common foot problems like athlete’s foot and other foot fungi, it’s important to have boots that are designed to keep your feet dry from both your sweat and the environment.

It’s important to buy a boot that fits correctly. "If your foot is in the boot and your toes are hitting the front of the boot as you are working, that’s probably not a good thing. You really want the load to hit your foot where the laces usually are, while you’re walking," Cirino said.

"If your toes are jamming into the boot and that takes the brunt of the load, you’re either going to have sore toes or lose toenails. In the long run, your toes will start deforming."

There are a wide variety of work boots on the market, and it is important to select the correct boot for the environment that it will be used in. Remember to think of your work shoes the same way you think of your tools or equipment. You don’t just buy anything. You buy the tool or machine that’s going to do the best job for you in a specific application or type of application. "You really have to look at the boot to see what it is designed for," Cirino said.

Roger Huard, senior vice president for Product Development for Wolverine Footwear Group, explained that one test that his company does on work boots involves testing safety toes for compression and impact.

"We make sure that the toe caps meet ASTM guidelines when we’re selling them in the United States. There are other guidelines for the European Union and Canada," Huard said. ASTM International is a voluntary standards development organization that provides technical standards for materials, products, systems, and services.

The impact test consists of dropping 50 pounds with a 1-inch rounded striker from 18 inches on the back edge of the toe cap. The compression test is carried out on a machine where 2,500 pounds of pressure is applied to the toe. One-half-inch clearance (the height of the safety cap after the test) is a minimum requirement to meet the standard.

All Wolverine safety boots meet and exceed the standard in any of the configurations – boot construction and toe cap material, according to Huard.

"We also test the outsoles for slip resistance and oil resistance and in some specific instances, flame resistance. The vast majority of our boots are built and tested for electrical hazards," Huard said.

"There is no ASTM-supported outsole slip-resistance standard in the United States at this moment. These tests were dropped in 2006. We nevertheless still test accordingly to continue comparing previous results. Wolverine World Wide invested funds in 2005 for a whole-shoe slip resistance tester that gives much closer results to an actual wear situation – simulating weight, angle and speed at the point of contact, using a variety of surfaces, including ice.

"Wolverine uses two oil-resistance methods, the U.S. method – Footwear Industries of America-319 (FIA-319) with engine oil – and the more aggressive European method with fuel oil (like kerosene). For heat resistance, Wolverine has three levels of outsole quality: basic, which provides a minimal resistance (up to 250 degrees Fahrenheit) and applies to polyurethane, thermoplastic polyurethane and polyvinyl chloride; standard work, which provides medium resistance (up to 400 degrees Fahrenheit) and applies to regular rubber compounds; and premium work, which provides high heat resistance (over 900 degrees Fahrenheit) and applies to specialty rubber compounds.

"ASTM has an electrical hazard standard for footwear. All of our work boots meet the specification of 14,000 volts at well below 1-mili Amper (mA) current leakage (the ASTM standard is three mAs). In addition, 99 percent of our work boots also meet the Canadian Standard Association’s (CSA) Electrical Shock Resistance (ESR) standard, which is 18,000 volts below 1-mA leakage.

"We also do some generic tests that are not specifically a function of safety shoes. We do abrasion tests, bond tests for soles and uppers, lace tests, and lining tests. There is a full battery of tests that our footwear goes through. Wolverine conducts numerous tests for materials and complete footwear. These include tear strength, stitch tear, flex resistance, and abrasion resistance (for fabrics) for leather and upper materials; Martindale abrasion and resistance to staining for linings; and Martindale abrasion, compression set, cushioning/shock absorption (on premium footbeds) for footbeds."

If you pay attention to the work boots you buy, you’ll find that you’ll suffer fewer foot problems and lower backaches; less foot damage and less frequent occurrences of fungi; greater safety and comfort for your toes; and when you get home at night and take them off, you won’t drive everyone out. We need a new version of Nancy Sinatra’s song. It should go something like, "These boots were made for workin’ and that’s just what they’ll do / Each and every day these boots will work for you."