The harmful effects of anti-fouling systems were considered by the International Maritime Organization''s Marine Environment Protection Committee (MEPC) for the first time in 1988, when the Paris Commission requested the MEPC to consider the need for measures to restrict the use of tributyltin (TBT) compounds on seagoing vessels. As a first step, the Committee at its thirtieth session in 1990 adopted resolution MEPC.46 (30) on ``Measures to control potential adverse impacts associated with the use of tributyltin compounds in anti-fouling paints'''', which recommends that IMO Member Governments adopt measures to eliminate the use of anti-fouling paint containing TBT on non-aluminium-hulled vessels of less than 25''m in length and eliminate the use of TBT-based anti- fouling paints with an average leaching rate of more than four micrograms of organotin per square centimetre per day. These recommendations were intended to be interim measures until IMO could consider a possible total prohibition of TBT compounds in anti-fouling systems. From 1990 onwards, MEPC was presented with TBT monitoring results which reconfirmed the toxicity of TBT compounds, as well as with information on existing alternatives, including their effectiveness and the risk posed to the marine environment by these systems. This 2005 edition, reproduces the texts of the International Convention on the Control of Harmful Anti-Fouling Systems on Ships, 2001, the four Conference resolutions, and the Guidelines developed and adopted by the Organization.