The Air Quality Limit Values (Wales) Regulations 2002
These regulations implement in Wales Council Directive 96/62/EC on ambient air quality assessment and management, Council Directive 99/30/EC relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead in ambient air, and Council Directive 2000/69/EC relating to limit values for benzene and carbon monoxide in ambient air.