Substances or preparations are considered dangerous when they need to be labelled with the R phrases 50 to 59 (e.g. R51 “Toxic to aquatic organisms”). Only specific products additionally require the hazard symbol N “Dangerous for the environment”.

R 50   Very toxic to aquatic organisms 
R 51   Toxic to aquatic organisms 
R 52   Harmful to aquatic organisms
R 53   May cause long-term adverse effects in the aquatic environment 
R 54   Toxic to flora 
R 55   Toxic to fauna
R 56   Toxic to soil organism
R 57   Toxic to bees
R 58   May cause long-term adverse effects in the environment
R 59   Dangerous for the ozone layer