Composition and method for bleaching a substrate

This invention relates to compositions and methods for catalytically bleaching substrates with atmospheric oxygen, using a metal-ligand complex as catalyst, which compositions are formulated as liquids. This invention also relates to a method of treating textiles, such as laundry fabrics, using a metal-ligand complex as catalyst whereby bleaching with atmospheric oxygen is catalysed after the treatment, wherein the treatment composition is formulated as a liquid. The invention relates to a liquid bleaching composition for catalytically bleaching substrates, especially laundry fabrics, with atmospheric oxygen or air. A liquid bleaching composition is provided comprising an organic substance which forms a complex with a transition metal, the complex catalysing bleaching of a substrate by atmospheric oxygen, and a liquid carrier or solvent, wherein the composition is substantially devoid of peroxygen bleach or a peroxy-based or -generating bleach system. Also provided is a method of bleaching a substrate comprising applying the liquid bleaching composition to the substrate. Also provided is a method of treating a textile by contacting the textile with the liquid bleaching composition, whereby the complex catalyses bleaching of the textile by atmospheric oxygen after the treatment.