Office of Public Sector Information
Regulation 13(6)
| Annual average | |
|---|---|
| Upper assessment threshold | 70% of limit value (3.5 μg/m³) |
| Lower assessment threshold | 40% of limit value (2 μg/m³) |
| Eight-hour average | |
|---|---|
| Upper assessment threshold | 70% of limit value (7 mg/m³) |
| Lower assessment threshold | 50% of limit value (5 mg/m³) |
| Annual average | |
|---|---|
| Upper assessment threshold | 70% of limit value (0.35 μg/m³) |
| Lower assessment threshold | 50% of limit value (0.25 μg/m³) |
| Hourly limit value for the protection of human health (NO2) | Annual limit value for the protection of human health (NO2) | Annual limit value for the protection of vegetation (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 limit value (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 limit value (19.5 μg/m³) |
| 24-hour average | Annual average | |
|---|---|---|
| Upper assessment threshold | 60% of limit value (30 μg/m³), not to be exceeded more than 7 times in any calendar year | 70% of limit value (14 μg/m³) |
| Lower assessment threshold | 40% of limit value (20 μg/m³), not to be exceeded more than 7 times in any calendar year | 50% of limit value (10 μg/m³) |
| Health protection | Ecosystem protection | |
|---|---|---|
| Upper assessment threshold | 60% of 24-hour limit value (75 μg/m³), not to be exceeded more than 3 times in any calendar year | 60% of winter limit value (12 μg/m³) |
| Lower assessment threshold | 40% of 24-hour limit value (50 μg/m³), not to be exceeded more than 3 times in any calendar year | 40% of winter limit value (8 μg/m³) |
The Air Quality Standards Regulations 2007