Regulation 18 Duty in relation to limit valuesI1

Northern Ireland departments shall ensure that levels of sulphur dioxide, nitrogen dioxide, benzene, carbon monoxide, lead and particulate matter do not exceed the limit values set out in Schedule 2.

In zones where levels of the pollutants mentioned in paragraph (1) are below the limit values set out in Schedule 2, Northern Ireland departments shall ensure that levels are maintained below those limit values and shall endeavour to maintain the best ambient air quality compatible with sustainable development.

WhereF2... the Department considers that a limit value has been exceeded for a reason attributable to natural sources, that limit value will not be considered to be exceeded for the purposes of these Regulations.

For the purposes of paragraph (3), the Department must prepare information, for the relevant zones and agglomerations, demonstrating that the exceedances are attributable to natural sources.