Category |
Description |
C2 – LOW |
Low level of pollution, mostly rural areas |
C3 – MEDIUM |
Most rural & urban areas with low level sulphur dioxide, acid, alkali & salt pollution |
C4 – HIGH |
Urban & industrial areas with moderate sulphur dioxide pollution &/or coastal areas with low salinity |
C5 – VERY HIGH |
Industrial areas with high humidity & aggressive atmospheres; Coastal & offshore areas with high salinity |