Does health and safety law specify air quality standards for workplaces?

UK law doesn’t set a single “universal” standard for workplace air, but it does require employers to provide clean, fresh air under the Workplace (Health, Safety and Welfare) Regulations. COSHH also sets Workplace Exposure Limits (WELs) for hundreds of hazardous substances.

So while there isn’t one number for overall air quality, employers are legally required to control pollutants, keep ventilation adequate, and ensure workers are not exposed to harmful concentrations of specific substances.