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Archive: Handling of boat hulls coated with antifouling products containing non-approved biocides

Actually, several antifouling biocides are no more allowed for production, sale and use in all EU countries. The biocides concerned are tri-butyltin, tri-phenlytin and diuron. From the end of January 2017 Irgarol must not been approved as well.

The use of organostannic compounds has been prohibited in several EU countries since 1998 and in all EU countries since 2008. Existing organostannic containing coatings should have been removed or sealed since then. Measurements with XRF-tools on boat hulls in Denmark, Sweden, Finland and Germany revealed up to 30% of boats with organostannic compounds present on the hull. As high numbers of boat are “second hand” ones, relevant numbers of boat owners do not know which coatings with which composition of biocides are present on the hull. On boats where the owner removed all old paint layers down to the primer, there should be no problem. On boats with a sandwich system of numerous paint layers, precautious measurements should be taken treating the hull after lifting the boat. Measurements of washwater of those boat hulls treated with high pressure (hp) water revealed high concentrations of TBT. These boats should be handled with care and exclusively cleaned by sponge and tap water. At the beginning of the next season light sanding with high graded sandpaper may be sufficient. Boats with fouled hulls which shall be treated by high pressure washing should use a wash down area with collection and filter systems. By the way, it should be mentioned that the washing of boat hulls coated with biocidal antifouling products is illegal on unprotected ground.

To avoid the imposition of unreasonable conditions it is recommended to take precautions for boats built before 2008 on which the composition of the existing paints layers is unknown. These boats should be excluded from hp-washing on unprotected ground and the removal of old paint layers down to the primer should performed with personal protection equipment and protection of the ground.
Following the certificate prescribed in the IMO Antifouling Convention LimnoMar proposes the use of this certificate for boat owners, boat clubs, dockyards and marinas to clarify the condition of the coating and to take appropriate measurements.

The certificate can be downloaded here:

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