Clearing paths and walkways

Salty solution

In sub-zero conditions car parks, paths and steps can very quickly become icy, creating a significant hazard. Naturally, public liability insurers expect you to do your best to limit these risks, but is reaching for the rock salt harmful to the environment?

There are still many questions to be answered about the long-term effects of surface salting but we can address the immediate concerns.

The risk

De-icing salts in the UK are primarily made from sodium chloride. This rock salt may be mixed with sand or grit and sometimes an anti-caking agent, e.g. sodium ferrocyanide. Salts, additives and any other materials present in the unrefined material are washed off on to the land and into water courses. This can harm fish and other aquatic creatures, e.g. by suddenly increasing the water’s salinity. Soil affected by run-off from hard surfaces will also be contaminated, with vegetation close to the treated area becoming scorched.

Tip 1. For the time being rock salt is regarded as non-toxic and you can use it without restriction.

Tip 2. Store your bags of salt off the ground and under cover. There are special requirements for larger quantities.

Tip 3. If the natural environment around you is sensitive, or you are close to a borehole or well, it’s good practice to limit the use of salt on the ground. Note. The first ten metres from the treated area is thought to be most at risk of contamination.

Prevention

Tarmac and concrete are more likely to become slippery than more permeable surfaces.

Tip. When redesigning external areas, consider gravel paths for less-used routes. Also ensure that surfaces drain as effectively as possible.

Non-intervention

Contrary to popular belief, there is no legal requirement to de-ice every hard surface. What’s required is to take reasonable steps to make your workplace safe. Since demand for parking spaces usually falls in prolonged cold spells, you may find that you can put some areas out of use.

Tip. Treat only those areas which need to be used or which can’t be made out of bounds. Cordon off parts which are untreated and slippery using tape, signs, barriers and/or bollards.

Alternatives

Alternative de-icing agents are available in pellet form. UK suppliers generally sell calcium chloride-based products. These require a lower application rate than salt and work at lower temperatures.

There’s still a chloride release to the environment, however, and there are other disadvantages such as cost, the environmental impacts of production and the corrosive nature of the substance.

Tip. Another option is to use sand. It absorbs sunlight and helps the surface to warm more quickly; it also improves traction. But make sure that it doesn’t clog your drains.