Industry News

Organotin Ban in Hull Paint Begins September 17

Published on 2008-06-03. Author : SpecialChem

An international convention banning the use of harmful organotin in anti-fouling paints used on the hulls of ships and yachts will enter into force on Sept. 17. Organotin compounds are those based on tin with hydrocarbon substituents.

The International Convention on the Control of Harmful Anti-Fouling Systems on Ships (AFS Convention) was adopted on Oct. 5, 2001 by the International Maritime Organization (IMO) as well as the United Nations' specialized agency with responsibility for safety and security of shipping and the prevention of marine pollution by ships.

Under the terms of the Convention, it enters into force 12 months after 25 states representing 25 percent of the world's merchant shipping tonnage have ratified it. With the ratification by the Republic of Panama in September, the AFS Convention was ratified by 25 states, with a combined 38.11 percent of the world's merchant shipping tonnage.

When the Convention is in force, ships and yachts will no longer be permitted to apply or re-apply organotin compounds, which act as biocides in their anti-fouling systems. Yachts either shall not bear such compounds on their hulls or external parts or surface or, for yachts already

carrying such compounds on their hulls, a coating that forms a barrier to such compounds will have to be applied to prevent them escaping from the underlying non-compliant anti-fouling systems. The Convention also establishes a mechanism to evaluate and assess other anti-fouling systems and prevent the potential future use of other harmful substances in these systems.

Anti-fouling paints are used to coat the bottoms of yachts to prevent sea life such as algae and mollusks from attaching themselves to the hull, which would slow the yacht and increase fuel consumption.

The AFS Convention defines anti-fouling systems as "a coating, paint, surface treatment, surface, or device that is used on a ship to control or prevent attachment of unwanted organisms."

In the early days of sailing ships, lime and later arsenic were used to coat ships' hulls. More recently, the modern chemicals industry developed effective anti-fouling paints using metallic compounds. These compounds slowly "leach" into the sea water, killing barnacles and other marine life that have attached to the ship.

One of the most popular anti-fouling paints, developed in the 1960s, contained the organotin compound tributylin (TBT), which was proven to cause deformations in oysters and sex changes in whelks. Unknown to the industry when initially introduced, long-term studies since then have shown that these compounds persisted in the water, killing sea life, harming the environment and possibly entering the food chain.

Today, there are a variety of effective anti-fouling systems available that do not contain TBT, such as organotin-free anti-fouling paints and biocide-free, non-stick coatings that have an extremely slippery surface. They prevent fouling from occurring and make it easier to clean when it does.

The Convention will apply to all yachts flying the flag of a party to the Convention, as well as yachts not entitled to fly their flag but that operate under their authority and to all yachts that enter a port, shipyard or offshore terminal of a party.

In other words, either your flag of registry will require compliance, or the port where the yacht calls will require compliance by the September deadline.

For private and commercial yachts of 400 gross tons and above, an initial survey must be conducted by the flag administration for issuance of the International Anti-Fouling Systems Certificate (IAFSC). Any future changes or replacements after the initial survey must be endorsed by the flag administration on the IAFSC.

For private and commercial yachts more than 24 meters in length but less than 400 gross tons, owners have the option of obtaining an IAFSC or self-declaring the type of anti-fouling system used on the hull. This declaration must be supported by specific documentation issued by the paint contractor.

In addition, the declaration shall be drawn up in the form corresponding to the model given in Appendix 2 of the AFS Convention. Remember, the deadline for compliance with this international regulation is only three months away.

Source: The Triton

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