With more options than ever before, safety footwear is anything but a one-size-fits-all purchase. As you evaluate your footwear program, there are many things to think about, such as job-site hazards, seasonal weather exposure and material durability. But don't overlook the bulk, weight and comfort of the boot itself. 

Innovations in footwear materials and construction are proceeding at a rapid pace, allowing the production of lightweight protective footwear that promises greater comfort and reduced fatigue. As you audit your footwear program, consider lightweight footwear choices that meet the appropriate ASTM standards for protective footwear. OSHA references ASTM F2412 Standard Test Methods for Foot Protection and ASTM F2413 Standard Specification for Performance Requirements for Protective Footwear in its footwear standard (29 Code of Federal Regulations 1910.136). 

Weighing the problems

In the past, protective footwear was typically bulky and heavy. While this has been a proven way of offering protection against many workplace hazards, that protection comes at a price. So what’s the problem with heavy boots? 

Simply put, a worker who wears a heavier boot is going to expend more energy. This is a common-sense insight that has been borne out by several research studies. Interestingly, one recent study showed that wearing heavier footwear significantly increased a person’s energy expenditure, even without causing major changes to heart rate, breathing rate or perceived exertion. In other words, the test subjects wearing heavier boots were working significantly harder, even if they didn’t realize it.

This is important because higher energy expenditure will lead to a higher level of fatigue — and fatigue increases the possibility of illnesses, injuries and accidents. Of course, the fatigue induced by heavy footwear is less significant than the fatigue induced by a sleepless night, but it’s real nevertheless, and it has an impact on safety.

Think of it this way: If an industrial worker takes 10,000 steps in a work day, that means that he or she is lifting and lowering a boot 10,000 times — so a boot that’s just one ounce heavier would be like lifting 625 additional pounds over the course of the day.

Use ASTM standards to select the right boot

Lighter footwear can reduce fatigue — but how can you be sure that it’s still offering effective protection? Look to ASTM F2412 and ASTM F2413. 

All boots that you provide onsite or in your facility should be ASTM tested and certified. With ASTM testing, each boot is evaluated against a set of predefined standards for safety and scored independently to allow footwear safety to be evaluated fairly.

 The ASTM standards cover a range of footwear stress tests, including compression and impact, puncture resistance and conductivity. Each test mirrors a real-world accident that can slow or injure workers. Impact testing simulates a tool falling on a foot, while puncture resistance mimics stepping on a nail. In environments with loose wires or where static buildup is a concern, other tests help ensure that boots will perform as expected to mitigate the possibility of an electrical hazard.

When these ASTM standards have been met, you can be confident that footwear will perform as expected in the situations that workers are likely to experience. 

Lighten your load

Modern boots with newer, more lightweight materials can meet the ASTM standards while still providing the same or better job-specific protection as traditional footwear. So what can make a boot lighter?

Much of the weight in a boot comes from the sole, which is traditionally thick and bulky to provide puncture protection and additional traction. Contemporary safety footwear can take advantage of lightweight, durable sole materials and leverage additional plating to shed weight without sacrificing protective power. 

Similarly, composite toe caps can replace steel toe caps, and fiberglass shanks can replace steel shanks. Although these nonmetallic toe caps and shanks are used most frequently to make protective footwear that can pass through metal detectors in high-security environments, these features may become more widespread as footwear weight becomes more of a concern. The use of nonmetallic materials results in only small decreases in overall weight, but it’s important to remember that every ounce counts.

Insulation is another feature that can add significant bulk and weight to a boot. Fortunately, new insulating materials are frequently introduced with ever more lightweight and breathable properties.

Synthetic upper and insole materials can be lighter than the traditional leather, while also providing additional ventilation, odor control and comfort. Synthetic uppers are currently not a mainstream offering on protective shoes, but this is an area to keep an eye on as materials science continues to advance.

Wearing the right shoe for the job is about more than comfort — but comfort is still important, as is preventing unnecessary fatigue. By choosing protective footwear that meets the ASTM standards, you can have confidence that it offers the necessary level of traditional protection, even if it takes advantage of the latest lightweight materials.

References

1. Ben M. Krings, Brandon L. Miller, Harish Chander, Hunter S. Waldman, Adam C. Knight, Matthew J. McAllister, Brent J. Fountain & JohnEric W. Smith (2018) Impact of occupational footwear during simulated workloads on energy expenditure, Footwear Science, DOI: 10.1080/19424280.2018.1460623
2. Nina L. Turner, Sharon Chiou, Joyce Zwiener, Darlene Weaver & James Spahr (2010) Physiological Effects of Boot Weight and Design on Men and Women Firefighters, Journal of Occupational and Environmental Hygiene, 7:8, 477-482, DOI: 10.1080/15459624.2010.486285
3. https://www.osha.gov/SLTC/workerfatigue/hazards.html