Original signatories were Denmark, France, Iceland, Norway, Portugal, Spain, and Sweden.
Later members included the United Kingdom (1975), the Netherlands (1975), Germany (1977), Finland (1979), Ireland (1982), and Belgium (1985).
The area covered by the treaty included the Atlantic and Arctic Oceans north of latitude 36°N, east of longitude 42°W and west of longitude 51°E, excluding the Baltic and Mediterranean Seas The Convention prohibited the dumping of halocarbons and organosilicon (with some exceptions), mercury and mercury compounds, cadmium and cadmium compounds, non-biodegradable plastics and other persistent materials, as well as "substances which have been agreed between the Contracting Parties as likely to be carcinogenic under the conditions of disposal.
"[1] It also restricted and required a permit for the dumping of arsenic, lead, copper, zinc and their compounds, as well as cyanides, and fluorides, pesticides, containers, "tar-like substances", scrap metal, and "other bulky wastes.
"[1] It also defined the considerations to be made in the issuance of dumping permits by each signatory state and required them to enforce the agreement within their territorial sea and make efforts to prevent dumping of materials outside the agreement's defined borders.