Metal deactivators, ormetal deactivating agents (MDA) arefuel additives andoil additives used to stabilize fluids by deactivating (usually bysequestering) metalions, mostly introduced by the action of naturally occurring acids in the fuel and acids generated inlubricants by oxidative processes with the metallic parts of the systems. Fuels desulfurized bycopper sweetening also contain a significant trace amounts of copper.
Metal deactivators inhibit thecatalytic effects of such ions, especiallycopper, retarding the formation of gummy residues (e.g.gels containing coppermercaptide).[1] Even concentrations of copper as low as 0.1 ppm can have detrimental effects.
An example of a metal deactivator used forgasoline andjet fuels issalen. It is used in turbine andjet fuels,diesel,heating oil, andgreases. It is approved for military and commercialaviation fuels.[2]Benzotriazole and its various derivatives are also common inlubricant formulas.