The Air Quality Limit Values (Wales) Regulations 2002

Regulations 4(1), 9(2), 10 (1) and (4), 12(6) and (7)

SCHEDULE 1 LIMIT VALUES, MARGINS OF TOLERANCE ETC.

PART I SULPHUR DIOXIDE

Limit values for sulphur dioxide

1.1  

	Averaging period	Limit value	Margin of tolerance(1)	Date by which limit value is to be met
1.  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	60 μg/m3 on 1st January 2003, reducing on 1st January of each following year by equal annual amounts to reach 0 μg/m3 by 1st January 2005	1st January 2005
2.  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	None	1st January 2005
3.  Limit value for the protection of ecosystems	Calendar year and winter (1st October to 31st March)	20 μg/m3	None

Alert threshold for sulphur dioxide

1.2  500 μg/m3 measured over three consecutive hours at locations representative of air quality over at least 100 km² or an entire zone or agglomeration, whichever is the smaller.

Minimum details to be made available to the public when the alert threshold for sulphur dioxide is exceeded

1.3  Details to be made available to the public should include at least:

• the date, hour and place of the occurrence and the reasons for the occurrence, where known;

• any forecasts of:

  • changes in concentration (improvement, stabilisation, or deterioration), together with the reasons for those changes,

  • the geographical area concerned,

  • the duration of the occurrence;

  • the type of population potentially sensitive to the occurrence;

  • the precautions to be taken by the sensitive population concerned.

PART II NITROGEN DIOXIDE (NO₂) AND OXIDES OF NITROGEN (NO_x)

Limit values for nitrogen dioxide and oxides of nitrogen

2.1  

	Averaging period	Limit value	Margin of tolerance	Date by which limit value is to be met
1.  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	70 μg/m3 on 1st January 2003, reducing on 1st January of each following year by equal annual amounts to reach 0 μg/m3 by 1st January 2010	1st January 2010
2.  Annual limit value for the protection of human health	Calendar year	40 μg/m3 NO2	14 μg/m3 on 1st January 2003, reducing on 1st January of each following year by equal annual amounts to reach 0 μg/m3 by 1st January 2010	1st January 2010
3.  Annual limit value for the protection of vegetation	Calendar year	30 μg/m3 NOx	None

Alert threshold for nitrogen dioxide

2.2  400 μg/m3 measured over three consecutive hours at locations representative of air quality over at least 100 km² or an entire zone or agglomeration, whichever is the smaller.

Minimum details to be made available to the public when the alert threshold for nitrogen dioxide is exceeded

2.3  Details to be made available to the public should include at least:

• the date, hour and place of the occurrence and the reasons for the occurrence, where known;

• any forecasts of:

  • changes in concentration (improvement, stabilisation, or deterioration), together with the reasons for those changes,

  • the geographical area concerned,

  • the duration of the occurrence;

  • the type of population potentially sensitive to the occurrence;

  • the precautions to be taken by the sensitive population concerned.

PART III PARTICULATE MATTER (PM₁₀)

	Averaging period	Limit value	Margin of tolerance	Date by which limit value is to be met
1.  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	10 μg/m3 on 1st January 2003, reducing on 1st January of each following year by equal annual amounts to reach 0 μg/m3 by 1st January 2005	1st January 2005
2.  Annual limit value for the protection of human health	Calendar year	40 μ g/m3 PM10	3.2 μg/m3 on 1st January 2003, reducing on 1st January of each following year by equal annual amounts to reach 0 μg/m3 by 1st January 2005	1st January 2005

PART IV LEAD

	Averaging period	Limit value	Margin of tolerance	Date by which limit value is to be met
Annual limit value for the protection of human health	Calendar year	0.5 μg/m3	0.2 μg/m3 on 1st January 2003, reducing on 1st January of each following year by equal annual amounts to reach 0 μg/m3 by 1st January 2005	1st January 2005

PART V BENZENE

	Averaging period	Limit value	Margin of tolerance	Date by which limit value is to be met
Limit value for the protection of human health	Calendar year	5μg/m3	5μg/m3 on 1st January 2003, reducing on 1st January 2006 and every 12 months thereafter by 1 μg/m3 to reach 0 μg/m3 by 1st January 2010	1st January 2010

PART VI CARBON monoxide

	Averaging period	Limit value	Margin of tolerance	Date by which limit value is to be met
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.
Limit value for the protection of human health	Maximum daily 8-hour mean	10mg/m3	4 mg/m3 on 1st January 2003, reducing every 12 months thereafter by 2 mg/m3 to reach 0 mg/m3 by 1 January 2005	1 January 2005

(1)

The figures for Margins of Tolerance for each of the relevant pollutants given in this Schedule are calculated from those given in Annex I of Directive 99/30/EC and Annexes I and II of Directive 2000/69/EC.