WFD list of priority substances
The Water Framework Directive was voted by the European Parliament and the European Council in October 2000 and entered into force in December 2000. It aims to establish a legal framework for the protection of water quality in European countries (for river water, sea water, groundwater and coastal water). The directive recognizes that specific measures have to be adopted at a European level against water pollution by individual pollutants, or groups of pollutants, presenting a significant risk to the aquatic environment and water used for the production of drink water.
These measures aim to progressively reduce the level of pollution for 33 priority substances, which could threaten human health or ecosystems. The goal is to decrease naturally occurring pollutants to the background value and man-made synthetic pollutants to values close to zero. The complete removal of emissions from all potential sources is obviously impossible for substances produced through natural processes, but the legal framework should prevent all emissions and discharges of those priority substances which derive from human activities.
The list of 33 priority substances was composed by the European Commission with a panel of experts in the field of chemistry and maritime pollution, delegates of the member states and European firms and the European Environment Agency. The framework states that the emissions of priority substances need to be reduced progressively. The priority substances include 13 priority hazardous substances. These are substances which are toxic, persistent and likely to bioaccumulate and other substances which give rise to equal concern. The emissions, discharges and losses of these substances need to be ceased or phased out.
The Directive on Priority Substances of 2008 (a daughter directive of the Water Framework Directive) also made a list of substances for which it should be investigated whether they should be included in the list of priority substances or priority hazardous substances. 
List of 33 priority substances
The following 33 substances and chemical compounds are included in the list of priority substances established by the European Union. Some of these priority substances are also priority hazardous substances.
List of 20 priority substances
The following 20 substances are priority substances, but not priority hazardous substances
- Di(2-ethylhexyl)phthalate (DEHP)
- Lead and its compounds
- Nickel and its compounds
List of 13 priority hazardous substances
The following 13 substances are priority substances and priority hazardous substances:
- Cadmium and its compounds
- Mercury and its compounds
- Polyaromatic hydrocarbons
- Tributyltin compounds
Substances subject to review for possible identification as priority substances or priority hazardous substances
The following substances and chemical compounds are included in the listof substances, established by the European Union, for which it should be reviewed whether they should be included in the list of priority substances or priority hazardous substances:
- Free cyanide
- Musk xylene
- Perfluorooctane sulphonic acid (PFOS)
- Quinoxyfen, Dioxins, PCB