The Air Quality Limit Values (Scotland) Regulations 2001 No. 224

SCHEDULE 1 LIMIT VALUES, MARGINS OF TOLERANCE ETC.

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 NO2 not to be exceeded more than 18 times a calendar year	290μg/m3 on 19th July 2001, reducing on 1st January of each following year by 10μg/m3 to reach 200μg/m3 by 1st January 2010	1st January 2010
2.  Annual limit value for the protection of human health	Calendar year	40μg/m3 NO2	58μg/m3 on 19th July 2001 reducing on 1st January of each following year by 2μg/m3 to reach 40μg/m3 by 1st January 2010	1st January 2010
3.  Annual limit value for the protection of vegetation	Calendar year	30 μg/m3 NOx	None	19th 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.