all waste shall be stored in such a way as to prevent its dispersal into the environment. Controlled incineration: This option can only be carried out in those facilities which, to the maximum extent practicable, reduce harmful emissions (controlled combustion incinerators). Only biodegradable waste can be incinerated. The solid residue of such incineration shall be removed from the Antarctic Treaty area. Disposal to the sea: Disposal of sewage and domestic liquid waste to the sea is allowed, exclusively in areas where conditions exist for its initial dilution and rapid dispersion (ie, in currents that go offshore). When the station exceeds 30 people, the Annex requires that such waste be previously treated, at least by maceration. This Annex also proposes a classification system for waste generated in Antarctica, which serves as a basis for keeping a record of waste and to facilitate studies aimed at evaluating the impacts on the environment of scientific activities and associated logistical support. To this end, this Annex establishes that the waste generated must be classified into five groups: • Group 1: sewage and domestic liquid waste, • Group 2: other liquid wastes and chemicals, including fuels and lubricants, • Group 3: solids to be combusted, • Group 4: other solid wastes, and • Group 5: radioactive material. To further reduce the impact of waste on the Antarctic environment, Annex III to the Protocol establishes that each National Programme* must prepare, review and periodically update waste treatment plans for bases, camps and vessels, specifying programmes for cleaning up existing waste disposal sites and abandoned work sites. *Note: A National Antarctic Programme is defined as “the entity with national responsibility for managing support for scientific research in the Antarctic Treaty Area on behalf of its government and in the spirit of the Antarctic Treaty”. Each signatory to the Antarctic Treaty normally establishes a National Antarctic Programme to coordinate its activities in Antarctica. Annex IV: Prevention of Marine Pollution This Annex establishes prohibitions and restrictions on the dumping of waste from ships, while operating in the Antarctic Treaty area. This Annex is part of the provisions of the Convention to prevent Marine Pollution from ships, known internationally as MARPOL 73/78 (originally signed in 1973, with amendments in 1978), within the framework of which, in 1990, it was agreed to grant Antarctic waters the status of Special Zone, where greater restrictions must be observed than in other international waters.