The Air Quality Limit Values (Wales) Regulations 2001

Regulations 2, 8(2), 9(1), 11(5)

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	150 μg/m3 (43%) on 19 July 1999, reducing on 1 January 2001 and every 12 months thereafter by equal annual percentages to reach 0% by 1 January 2005	1 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	1 January 2005
3.  Limit value for the protection of ecosystems	Calendar year and winter (1 October to 31 March)	20 μg/m3	None	19 July 2001

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	200μg/m3 NO2not to be exceeded more than 18 times a calendar year	50% on 19 July 1999, reducing on 1 January 2001 and every 12 months thereafter by equal annual percentages to reach 0% by 1 January 2010	1 January 2010
2.  Annual limit value for the protection of human health	Calendar year	40 μg/m3NO2	50% on 19 July 1999 reducing on 1 January 2001 and every 12 months thereafter by equal annual percentages to reach 0% by 1 January 2010	1 January 2010
3.  Annual limit value for the protection of vegetation	Calendar year	30 μg/m3 NOx	None	19 July 2001

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	50μg/m3 PM10 not to be exceeded more than 35 times a calendar year	50% on 19 July 1999, reducing on 1 January 2001 and every 12 months thereafter by equal annual percentages to reach 0% by 1 January 205	1 January 2005
2.  Annual limit value for the protection of human health	Calendar year	40 μg/m3PM10	20% on 19 July 1999 reducing on 1 January 2001 and every 12 months thereafter by equal annual percentages to reach 0% by 1 January 2005	1 January 2005

PART IV LEAD

	Averaging Period	Limit value	Margin of tolerance	Date by which limit value is to be met
Annualr limit value for the protection of human health	Calendar year	0.5μg/m3 PM10	100% on 19 July 1999, reducing on 1 January 2001 and every 12 months thereafter by equal annual percentages to reach 0% 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 1 of Directive 99/30/EC. This gave a figure above the limit value for each relevant pollutant, reducing by equal annual percentages from the date of entry into force of that Directive in 1999.