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