SCHEDULE 1 Air Quality standards

PART 1 Limit values for Group A pollutants

Benzene
	Averaging period	Limit value	Attainment date
Limit value for the protection of human health	Calendar year	5 μg/m³	1st January 2010

Carbon monoxide
For the purposes of this table, the maximum daily 8-hour mean concentration shall be selected by examining 8-hour running averages, calculated from hourly data and updated each hour. Each 8-hour average so calculated shall be assigned to the day on which it ends, i.e. the first calculation period for any one day shall be the period from 17:00 on the previous day to 01:00 on that day; the last calculation period for any one day shall be the period from 16:00 to 24:00 on that day.
	Averaging period	Limit value
Limit value for the protection of human health	Maximum daily 8-hour mean	10 mg/m³

Lead
	Averaging period	Limit value
Annual limit value for the protection of human health	Calendar year	0.5 μg/m³

Nitrogen dioxide (NO2) and oxides of nitrogen (NOx)
	Averaging period	Limit value	Attainment date
Hourly limit value for the protection of human health	1 hour	200 μg/m³ NO2, not to be exceeded more than 18 times a calendar year	1st January 2010
Annual limit value for the protection of human health	Calendar year	40 μg/m³ NO2	1st January 2010
Annual limit value for the protection of vegetation	Calendar year	30 μg/m³ NOx	

PM10
	Averaging period	Limit value
24-hour limit value for the protection of human health	24 hours	50 μg/m³ PM10, not to be exceeded more than 35 times a calendar year
Annual limit value for the protection of human health	Calendar year	40 μg/m³ PM10

Sulphur dioxide
	Averaging period	Limit value
Hourly limit value for the protection of human health	1 hour	350 μg/m³, not to be exceeded more than 24 times a calendar year
Daily limit value for the protection of human health	24 hours	125 μg/m³, not to be exceeded more than 3 times a calendar year
Limit value for the protection of ecosystems	Calendar year and winter (1st October to 31st March)	20 μg/m³