Division 2 Nitrogen dioxide and oxides of nitrogen
United Kingdom
| Hourly limit value for the protection of human health (NO2) | Annual limit value for the protection of human health (NO2) | Annual critical level for the protection of vegetation and natural ecosystems (NOx) | |
|---|---|---|---|
| Upper assessment threshold | 70 % of limit value (140 μg/m3, not to be exceeded more than 18 times in any calendar year) | 80 % of limit value (32 μg/m3) | 80 % of critical level (24 μg/m3) |
| Lower assessment threshold | 50 % of limit value (100 μg/m3, not to be exceeded more than 18 times in any calendar year) | 65 % of limit value (26 μg/m3) | 65 % of critical level (19,5 μg/m3) |