Toxic substances formally identified as potentially harmful to aquatic life

The Dangerous Substances Directive

Convention on the Protection of the Marine Environment of the North East Atlantic

Ministerial Conferences on the Protection of the North Sea

Various studies carried out for the Nature Conservancy Council and English Nature have highlighted and investigated areas of concern with regard to the marine environment. Nixon et al (1992) highlight a variety of toxic contaminants of concern based on List I and List II substances (from the Dangerous Substances Directive 76/464/EEC) and Red List substances. Subsequently, other studies have conducted more in-depth analysis of some of the issues raised by Nixon et al.

In addition to the issues raised by Nixon et al (1992), contaminants of importance to marine waters can be identified and are reflected in the legislation controlling discharges to estuarine, coastal and marine waters. Priority lists have been drawn up by various authorities and conferences related to the protection of marine waters.

Those considered of relevance are the Dangerous Substances Directive, The Convention on the Protection of the Marine Environment of the North-East Atlantic and the Ministerial Conferences on the Protection of the North Sea.

The Dangerous Substances Directive

In 1976, the EU Council of Ministers adopted the Dangerous Substances Directive (76/464/EEC) to control pollution caused by certain dangerous substances discharged into the environment. The Directive established two lists of compounds:

List I dealing with substances regarded as being particularly dangerous because of their toxicity, persistence and bioaccumulation. Pollution by List I substances must be eliminated; and

List II containing substances which are less dangerous but which nevertheless have a deleterious effect on the aquatic environment. Pollution by List II substances must be reduced.

In the last two years, the UK has added a number of new chemicals to List II. The two lists as they currently stand are given in Tables 1 and 2.

Table 1 Agreed List I substances

Cadmium Mercury Lindane (hexachlorocyclohexane)
Pentachlorophenol DDT Carbon tetrachloride
Chloroform Hexachlorobenzene Hexachlorobutadiene
Dieldrin Aldrin Isodrin
Endrin 1,2-dichloroethane Trichloroethylene
Perchloroethylene Trichlorobenzene  


In addition to the chemicals adopted as List II substances (Table 2), Department of the Environment, Transport and the Regions (DETR) and Environment Agency have been conducting programmes for deriving EQSs for the protection of aquatic life (including marine organisms). Although not adopted into legislation, these EQSs may be used as guidance for consenting discharges. Those chemicals for which EQSs have been agreed (and are not adopted into legislation) are given below.

Table 2a - List II substances for which EQSs have been adopted by the UK

Arsenic Boron
Chromium Copper
Iron Lead
Mothproofers Nickel
Organotins pH
Vanadium Zinc

Table 2b - List II substances for which EQSs have recently been adopted

Arsenic Atrazine
Azinphos-methyl Benzene
Biphenyl 4-chloro-3-methyl phenol
Chloronitrotoluenes 2-chlorophenol
2,4-dichlorophenol Dichlorvos
Dimethoate Endosulfan
Fenitrothion 2,4-D
Bentazone Demeton
Linuron Mecoprop
Naphthalene Omethoate
Simazine Trifluralin
Trichloroethanes Triazophos
Toluene Xylenes

Table 3 Chemicals for which EQSs for the protection of saltwater life have been agreed (but not adopted into legislation)

Aluminium Ammonia Abamectin
Ivermectin Doramectin Bromine
Bromoxynil Carbendazim Chlorine
Chlorine dioxide Chlorothalonil Chlorotoluron
Chlorpropham Cobalt Cyanide
Dichlorobenzenes Dichlorphen Diflubenzuron
EDTA Ethofumesate Fluoride
Flusilazole Formaldehyde Imazethypyr
Inorganic tin Ioxynil Isoproturon
Maneb Macozeb Manganese
Malachite green Mevinphos NTA
Nonylphenol Octylphenol Oxolinic acid
Oxytetracycline Pendimethalin Phthlates
Pirimiphos-methyl Phenol Propyzamide
Pirimicarb Prochloraz Silver


Convention on the Protection of the Marine Environment of the North East Atlantic

The Convention on the protection of the marine environment of the North-East Atlantic replaces the 1972 Oslo Convention on Waste Dumping at Sea and the 1974 Paris Convention on pollution of the North Sea and Adjacent Areas from Land-Based Sources. The new Convention requires signatory countries to prevent and, where possible, eliminate pollution of the marine environment. Previous Conventions merely required a reduction in pollution.

The Convention places particular emphasis on preventing pollution from diffuse sources. To this end, a list of substances that contribute to diffuse pollution has been drawn up.

Table 4 - Priority substances identified under the North Atlantic Marine Convention as contributing to diffuse pollution

Brominated flame retardants
Chlorinated paraffins
Metals (Cd, Hg, Cu, Zn, Pb, As, Cr, Ni)
Nonyl phenol ethoxylates
Organotin compounds
Polyaromatic hydrocarbons
PCBs and PCB substitutes
Polybrominated naphthalenes
Timber treatment chemicals
Triazine herbicides

Ministerial Conferences on the Protection of the North Sea

Concern about the quality of the North Sea has resulted in a series of Conferences of the Environment Ministers of countries bordering the North Sea. Decisions reached at these Conferences have had a significant impact on the development of policy and legislation for the protection of the aquatic environment in Western Europe. The first Conference was held in Bremen in 1985, subsequent meetings have been held in London and the Hague and the latest Conference was held in Esjberg in June 1995.

Second Ministerial Conference

Third Ministerial Conference

The Fourth North Sea Conference