Many companies manufacture and sell safety shoes to minimize the risk of injuries or accidents such as falls. Unfortunately, the designations "skid resistant" and "slip resistant" are not well defined nor enforced by a regulatory agency. Consequently, the difference between two kinds of safety shoes may be minimal at best. The determining factor should be functionality when choosing a skid resistant shoe versus a slip resistant shoe.
The Occupational Safety and Health Administration (OSHA) has not defined "skid resistant" or "slip resistant." Safety shoes designed to prevent slips and falls are rated by dry static coefficient, a ratio of the force of friction between two objects and the force that presses them together. Many retailers will post the coefficients of various shoes they offer. However, other label designations are left up to the shoe manufacturers and retailers.
The material used to make the heel and sole of a shoe is the key factor in how well a shoe will perform. Heels and soles made of softer materials are better able to "grab" the surface on which you walk or stand, making them more resistant to slipping and skidding. Most testing of shoes is performed on clean dry surfaces, so take that into account when choosing a safety shoe. The employer's requirements, recommendations and internal safety program should guide the ultimate choice of a safety shoe.
Until OSHA defines "skid resistant" and "slip resistant" and has the ability to enforce those definitions, measure how well a shoe performs against any label it may bear. If a shoe labeled skid resistant has successfully minimized falls, then you can reasonably expect it will work for you under similar circumstances. A good rule of thumb when choosing a shoe is to find out what kind of safety program a particular workplace has and what type of shoe they most commonly recommend or use.
Be wary of marketing terms that provide little or no actionable information. "Restaurant-tested and approved," for example, has no meaning in the absence of information regarding a specific test or endorsement. "Patent-pending design" may indicate a unique design feature but provides no information about either skid or slip resistance. "Safety shoe" as a designation does not provide information regarding skid or slip resistance.
Remember that the terms "skid resistant" and "slip resistant" do not refer to an objective standard. One retailer may designate a shoe slip resistant, while another retailer may designate the same shoe skid resistant. Whenever possible, contact the employer or agency where the work will be performed and ask for specific guidance regarding footwear. The best information you can be given is a specific dry static coefficient. If that is not available, ask about the type of footwear chosen by most workers.