The Air Quality Limit Values Regulations 2001

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	120 μg/m3 on 19th July 2001, 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	19th 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, 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.

(1)

The figures for margins of tolerance for each of the relevant pollutants given in this Schedule are calculated from those given in Annexes I to IV to Directive 99/30/EC.