Paragraph
England and Wales
Sulphur dioxide
| Averaging period | Limit value |
|---|---|
| One hour | 350 μg/m3, not to be exceeded more than 24 times a calendar year |
| One day | 125 μg/m3, not to be exceeded more than 3 times a calendar year |
Nitrogen dioxide
| Averaging period | Limit value |
|---|---|
| One hour | 200 μg/m3, not to be exceeded more than 18 times a calendar year |
| Calendar year | 40 μg/m3 |
Benzene
| Averaging period | Limit value |
|---|---|
| Calendar year | 5 μg/m3 |
Carbon monoxide
| Averaging period | Limit value |
|---|---|
| Maximum daily eight hour mean M1 | 10 mg/m3 |
Lead
| Averaging period | Limit value |
|---|---|
| Calendar year | 0.5 μg/m3 |
PM10
| Averaging period | Limit value |
|---|---|
| One day | 50 μg/m3, not to be exceeded more than 35 times a calendar year |
| Calendar year | 40 μg/m3 |
PM2·5
| Averaging period | Limit value | Margin of tolerance | Date by which limit value is to be met |
|---|---|---|---|
| Calendar year | 25 μg/m3 | 20% on 11 June 2008, decreasing on the next 1 January and every 12 months thereafter by equal annual percentages to reach 0% by 1 January 2015 | 1 January 2015 |
Annotations
Marginal citations
- M1
The maximum daily eight hour mean concentration of carbon monoxide must be selected by examining eight hour running averages, calculated from hourly data and updated each hour. Each eight hour average so calculated must be assigned to the day on which it ends, that is, the first calculation period for any one day will be from 17:00 on the previous day to 01:00 on that day, and the last calculation period for any one day will be the period from 16:00 to 24:00 on that day.