Extension Toxicology Network
A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Michigan State University, Oregon State University, and University of California at Davis. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program.
Tributyltin (TBT) is the active ingredient of many products that act as biocides against a broad range of organisms. It is primarily used as an antifoulant paint additive on ship and boat hulls, docks, fishnets, and buoys to discourage the growth of marine organisms such as barnacles, bacteria, tubeworms, mussels and algae.
TBT by itself is unstable and will break down in the environment unless it is combined with an element such as oxygen. One of the most common TBT compounds is bis(tributyltin) oxide, or TBTO. This form has been the subject of most TBT testing.
TBTO and eight additional TBT compounds are registered for use as marine antifoulants. Other TBT compounds are used as disinfectants, fungicidal wood preservatives, textile disinfectants, and stabilizers in PVC resin. Paper and pulp mills, cooling towers, breweries, textile mills and leather-processing facilities may also use some forms of TBT. Collectively these compounds are refered to as organotins.
All of the organotins are now regulated by the "Organotin Antifouling Paint Control Act of 1988." This act regulates the use of these materials in paints and sets standards for the amount of biocides that can leach from the paint into water.