Choosing slip-resistant footwear from the whole host of products on the market can be difficult. Sole descriptions are varied, from 'improving the grip performance' to 'excellent multi-directional slip-resistance'. Often, footwear is just described as 'slip-resistant' and the brochure does not describe the conditions for which the footwear is most suitable.
Footwear selection has to take account of a number of factors in addition to slip resistance, such as comfort, durability and any other safety features required, such as toe protection. The final choice may have to be a compromise.
- Accidents are expensive – there are many hidden and uninsured costs. With footwear, like any product, you tend to get what you pay for. Ensure you buy footwear which will do the job – this will not necessarily be the cheapest. But it may be more comfortable or attractive – ensuring that staff wear it, and it may last longer.
- Specify the main surfaces and contaminants which cause slip risks in your workplace, and seek your supplier's advice on suitable footwear.
- Some generally slip-resistant footwear may not be suitable in specific demanding conditions. For example, footwear that performs well in the wet might not be suitable on oily surfaces or where there are sticky food spillages which clog up the cleats.
- You can commission additional slip testing through the supplier – eg on surfaces/ contaminants representative of your workplace.
- Consider asking your supplier to provide trial pairs to help you make the right choice, and do not select footwear on the basis of brochure descriptions or laboratory test results alone.
- Footwear trials should involve a representative sample of the workforce and last long enough to produce meaningful results. Remember - workers may not wear footwear if it is uncomfortable or impractical, no matter how effective it is.
Key points on soles and walking surfaces
- The sole tread pattern and sole compound are both important for slip resistance. Generally a softer sole and close-packed tread pattern work well with fluid contaminants and indoor environments. A more open pattern works better outdoors or with solid contaminants. The only sure way to tell is to trial footwear in your environment.
- Tread patterns should not become clogged with any waste or debris on the floor – soles should be cleaned regularly. If soles do clog up then look for an alternative design of sole, eg with a wider space between the cleats and a deeper tread pattern.
- Slip resistance properties can change with wear; for example, some soles can deteriorate with wear, especially when the cleats become worn down.
- Have a system for checking and replacing footwear before it becomes worn and dangerous.
- The correct choice of footwear on wet or contaminated profiled steel or aluminium surfaces, eg chequer plate, is important. With some footwear the surface profiles do not provide the improvement in slip resistance that might be expected.
- 'Oil-resistant' does not mean 'slip-resistant' – the former is just a statement that the soles will not be damaged by oil.
Testing for slip resistance
Check with your supplier whether the footwear you are interested in has actually been tested for slip resistance – older models might not have been. Where footwear has been tested, coefficient of friction (CoF) test values must be available. CoF data can be requested from the supplier. Some suppliers now publish it in their catalogues. The higher the CoF, the better the slip resistance. Look for CoF results higher than the minimum requirements set out in annex A of EN ISO 20345/6/7: 2004 (A1:2007) - the standards for safety, protective and occupational footwear.
The safety features of footwear, including slip resistance, are tested according to a set of European test standards written into EN ISO 20344:2004 (A1: 2007). Footwear which has passed the EN test for slip resistance will be marked with one of the following codes, SRA, SRB or SRC.
The codes indicate that the footwear has met the specified requirements when tested as follows:
- SRA – tested on ceramic tile wetted with dilute soap solution;
- SRB – tested on smooth steel with glycerol;
- SRC – tested under both the above conditions.
It should be noted that these test surfaces are not wholly representative of all underfoot surfaces, so additional information may be needed to help to identify the best slip-resistant shoes for your particular environment.
The Health and Safety Laboratory (HSL) carries out research on footwear testing for HSE, and they have developed an in-house test which they have used for testing many footwear types. See:
RR801 - A study of the effect of modifying the European Standard mechanical slip resistance test for footwear
If footwear has helped you in preventing slips accidents, HSE would like to hear about it and to publicise it as a case study. Contact us.