The Importance of Outsole Design to Workplace Safety

Wearing safety shoes or work boots that meet both CSA standards and specific work safety requirements for height and material are two important factors in getting the right safety footwear. But the outsole design will also have a significant impact on safety. Why?

If someone is working on surfaces with materials that can collect or stick to the worker's shoes, then they can pose a risk for slips, trips and falls. A great example, and one that most people wouldn't think of, is a pharmaceutical manufacturing floor, where items like pills can actually stick in the grooves of the sole of the worker's shoes if the outsole design doesn't prevent it.  In other work environments, elements like moisture, oil, chemicals, grass, gravel and uneven earth, that can create stability and safety issues, can be addressed by selecting outsoles that help repel or divert materials away from the safety footwear and reduce the risk of injury from slips, trips and falls for the worker.

 

With such a wide range of safety footwear available, it may seem there’s a lot to know, but it really comes down to 3 factors related to the sole (or outsole). And much like car tire design, they involve pattern, material and terrain.

In general the more surface area and the busier the pattern, the better the traction. Take a look at these examples.

 

Pattern #1.  This pattern has flat surface which make it best for clean, dry surfaces, typically indoors.

Pattern #2.  Lots of surface area and good channels.  This sort of sole pattern is not unlike an all-season radial tire.  The large surface area gives your employees lots of contact with the walking surface and the well-defined channels help to channel liquids like water away to avoid hydroplaning.

Pattern #3.  A cross between #2 & #4.  It has a slightly deeper lug pattern than #2, but more surface area then #4.  It is suitable for outdoor wear on concrete, asphalt, and somewhat rough terrain.

Pattern #4.  This sole pattern has a deep lug and is suitable for rugged outdoor work such as forestry.  It’s not unlike the types of tires you would find on an All-Train-Vehicle (ATV).  These are good for climbing up dirt or grassy hills and are good for walking on gravel but don’t provide good traction for smoother or slicker surfaces.

Material 

Polyurethane is a lightweight soling material.  It typically is oil & chemical resistant, abrasion resistant and offers a high degree of comfort on hard surfaces

Rubber is very diverse in nature.  Some rubber formulas can be soft and pliable; these types tend to offer better traction in cold weather applications, along the same lines as a winter tire.

Nitrile rubber is a highly heat-resistant (up to 300°C) rubber soling material that has excellent chemical and abrasion resistance.  It also offers excellent traction both in oily environments and in cold weather

Thermoplastic Polyurethane (T.P.U.) is a urethane formula with a rubber compound added to it.  The rubber compound makes the TPU perform better in colder temperatures and improves its abrasion resistance.

Dual-density is a combination of  softer, low density material made from E.V.A or polyurethane and then add a skin that serves as the sole.  E.V.A offers good traction especially in cold weather. P.U (Polyurethane) versions provide “all-season” traction.

Terrain 

Understanding the surfaces your employees work on is just as important. Concrete, asphalt, gravel, indoor/outdoor, hot/cold temperatures each play an important contributing factor in how slip-resistant your employees’ safety footwear will be. More importantly, they help us recommend the best safety footwear.

We’re here to help

Our experts in safety footwear fit, comfort and safety have “kicked the tires” for every type of industry and work environment and can help evaluate the right outsole pattern and material for the terrain your employees are working on. So whether you are providing direction to your employees or are looking for a full footwear solution for your business, we’re here to help.