International Convention on the Control of Harmful Anti-fouling Systems on Ships
The International Convention on the Control of Harmful Anti-fouling Systems in Ships (AFS Convention) is a 2001 International Maritime Organization (IMO) treaty whereby states agree to prohibit the use of harmful anti-fouling paints and other anti-fouling systems that contain harmful substances. In particular, the use of the organotin tributyltin is prohibited, since leaching of that chemical from the hulls of ships has been shown to cause deformations in oysters and sex changes in whelks.