Present Status of Antifouling Systems in Japan: Tributyltin Substitutes in Japan

Abstract

An international conference held by the International Maritime Organization in October 2001 adopted an “International convention on the control of harmful anti-fouling systems on ships.” This treaty includes bans on the use of harmful organotin compounds, which act as biocides in paint products. The Japanese government ratified the treaty in July 2003. The Japan Paint Manufacturers' Association (JPMA) has commenced a program of self-control of antifouling systems in Japan and has issued on their website a list of registered paint products with and without certain biocides. The purpose of this review is to assess the status of the antifouling systems that are being used in Japan, based on the JPMA list. A total of 380 paint products from ten paint companies were registered by June 2005. Sixteen biocides are registered in 359 products, and the remaining 21 products contain no biocides. Single biocides are used in 60 products, as two-mixtures in 200 products, as three-mixtures in 80 products, and as four-mixtures in 19 products. Five biocides, such as cuprous oxide, triphenylborane-pyridine, Sea-Nine 211, copper thiocyanate, and chlorothalonil, are used as a single product. Combinations such as cuprous oxide and copper pyrithione, zinc pyrithione and triphenylborane-pyridine, cuprous oxide and Diuron, and cuprous oxide and zinc pyrithione are mainly used in two-biocide mixtures to produce synergistic antifouling effects.