Legislation Prohibiting TBT-Coated Hulls on Ships in United States Imminent

According to an article that appeared in BNA, legislation that would prohibit vessels with hulls coated with tributyltin (TBT) from entering U.S. waters is imminent. Once enacted, the law would bring U.S. law into compliance with provisions of the International Maritime Organization's International Convention on the Control of Harmful Anti-fouling Systems on Ships. The BNA report notes that a House subcommittee member expressed doubts at a June 10 hearing over how the Coast Guard would enforce a prohibition on foreign vessels using a toxic anti-fouling system from entering U.S. waters.

The hearing was called by the House Subcommittee on Coast Guard and Maritime Transportation "to help inform the development of legislation" to bring U.S. law into compliance with the convention signed in September 2008. Thirty-eight other nations are signatories to the convention.

A 1988 law, The Organotin Anti-Fouling Paint Control Act, prohibits the sale, purchase or application of TBT-based anti-fouling systems. TBT, considered to be "highly toxic" to the marine environment, is an effective anti-fouling agent that became the standard worldwide in the 1960s and 1970s, but its harmful effects on marine life were not known at the time.

In addition to keeping the domestic TBT ban in place, the draft legislation would establish a system for testing and assessing the environmental impact of any other anti-fouling coatings, and would also prohibit ships with TBT coatings from entering the waters of any nation that signed the convention, according to the subcommittee.

Anti-fouling systems are chemical coatings applied to a ship's hull to control the buildup of biological organisms. According to the subcommittee, as many as 4,000 marine species—commonly algae, mussels, plants and various microorganisms—can foul a vessel's hull and add as much as 6,000 tons of excess weight to a large vessel in less than six months. Fouling increases fuel consumption, accelerates deterioration of the hull, slows down the vessel's movement, and introduces invasive species into marine ecosystems, according to the subcommittee.

According to EPA, neither the U.S. Navy nor the Coast Guard has used TBT since the 1988 ban on it was enacted.

Date Posted: July 1, 2009