All employers owe a duty of care to ensure their employees are safe at work, this has been the law for 40 years but it is also a qualified duty to the reasonably practicable standard. It is not an absolute guarantee but retailers will be alert to the obligation, as expressed by the Supreme Court, to look for obvious risks and take reasonable steps to guard against them.

Vehicle emissions in Oxford Street, one of the capital‘s prime shopping areas, are said to be well above the EU limit. This is of concern to the Mayor of London and he is introducing low emission buses as well as reducing the number of buses using this route.

But discussions are ongoing about the need to update the Clean Air Act to address such pollution.

In the meantime, the UK currently faces concurrent legal action from Client Earth (an NGO) and the European Commission this week for its breaches of EU defined NO2 limits in a number of air quality zones – in London and Oxford Street. Commentators may well feel this is a risk which is now so obvious that retailers should be protecting their staff against any potential adverse effects such as breathing difficulties.

The monitoring has no doubt been done at pavement level or the kerbside so for retailers to be acting upon it they would need to know the levels present in their individual stores, which is likely to be very different. Only then can they analyse the risks and consider how they should respond.

This is not necessarily another case of over zealous interpretation of health and safety law but it may well be another area for employers to consider when discharging their duty to employees in the same way as if it were an exposure to excessive noise or a manual handling risk.

Where you are located will be a starting point in looking at the risks from the nitrous oxide levels and deciding how to respond. Take time to document your thought processes so if you decide no action is required you can show why you reached that conclusion.

Do not, however, rush into action without proper consideration of the circumstances of your store and your staff.

It should be remembered that Air pollution is estimated to have an effect equivalent to 29,000 deaths each year and is expected to reduce the life expectancy of everyone in the UK by six months on average at a cost of around £16bn per year. If it were possible to demonstrate that an individual or a group of people‘s health had suffered due to the high levels of NO2, then it is feasible that they could bring a claim against the UK government for damages to compensate them for the harm the have suffered.

Such a claim would be based on the premise that if the UK government had implemented an effective policy as required by the EU, then NO2 levels would have been better managed thereby avoiding any adverse impacts on the health of Londoners and those working on Oxford Street.