Directive 2008/50/EC of the European Parliament and of the CouncilShow full title

ANNEX XI U.K. LIMIT VALUES FOR THE PROTECTION OF HUMAN HEALTH

A. Criteria U.K.

Without prejudice to Annex I, the following criteria shall be used for checking validity when aggregating data and calculating statistical parameters:

a The requirements for the calculation of annual mean do not include losses of data due to the regular calibration or the normal maintenance of the instrumentation.
Parameter	Required proportion of valid data
One hour values	75 % (i.e. 45 minutes)
Eight hours values	75 % of values (i.e. 6 hours)
Maximum daily 8-hour mean	75 % of the hourly running eight hour averages (i.e. 18 eight hour averages per day)
24-hour values	75 % of the hourly averages (i.e. at least 18 hour values)
Annual mean	90 %a of the one hour values or (if not available) 24-hour values over the year

B. Limit values U.K.

a Already in force since 1 January 2005
b The maximum daily eight hour mean concentration will be selected by examining eight hour running averages, calculated from hourly data and updated each hour. Each eight hour average so calculated will be assigned to the day on which it ends i.e. the first calculation period for any one day will be the period from 17:00 on the previous day to 01:00 on that day; the last calculation period for any one day will be the period from 16:00 to 24:00 on that day.
c Already in force since 1 January 2005. Limit value to be met only by 1 January 2010 in the immediate vicinity of the specific industrial sources situated on sites contaminated by decades of industrial activities. In such cases, the limit value until 1 January 2010 will be 1,0 µg/m3. The area in which higher limit values apply must not extend further than 1 000 m from such specific sources.
Averaging Period	Limit value	Margin of tolerance	Date by which limit value is to be met
Sulphur dioxide
One hour	350 µg/m3, not to be exceeded more than 24 times a calendar year	150 µg/m3 (43 %)	—a
One day	125 µg/m3, not to be exceeded more than 3 times a calendar year	None	—a
Nitrogen dioxide
One hour	200 µg/m3, not to be exceeded more than 18 times a calendar year	50 % on 19 July 1999, decreasing on 1 January 2001 and every 12 months thereafter by equal annual percentages to reach 0 % by 1 January 2010	1 January 2010
Calendar year	40 µg/m3	50 % on 19 July 1999, decreasing on 1 January 2001 and every 12 months thereafter by equal annual percentages to reach 0 % by 1 January 2010	1 January 2010
Benzene
Calendar year	5 µg/m3	5 µg/m3 (100 %) on 13 December 2000, decreasing on 1 January 2006 and every 12 months thereafter by 1 µg/m3 to reach 0 % by 1 January 2010	1 January 2010
Carbon monoxide
maximum daily eight hour meanb	10 mg/m3	60 %	—a
Lead
Calendar year	0,5 µg/m3 c	100 %	—c
PM10
One day	50 µg/m3, not to be exceeded more than 35 times a calendar year	50 %	—a
Calendar year	40 µg/m3	20 %	—a