Paragraph
England and Wales
Sulphur dioxide
| Averaging period | Critical level |
|---|---|
| Calendar year and winter (1 October to 31 March) | 20 μg/m3 |
Oxides of nitrogen
| Averaging period | Critical level |
|---|---|
| Calendar year | 30 μg/m3 NOx |
England and Wales
Sulphur dioxide
| Averaging period | Critical level |
|---|---|
| Calendar year and winter (1 October to 31 March) | 20 μg/m3 |
Oxides of nitrogen
| Averaging period | Critical level |
|---|---|
| Calendar year | 30 μg/m3 NOx |