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 |
| 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 |