Butyl methacrylateButyl methacrylate is the organic compound with the formula C4H9O2CC=CH2. A colorless liquid, it is a common monomer for the preparation of methacrylate polymers. It is typically polymerized under free-radical conditions.Health hazardsIn terms of the acute toxicity of butyl methacrylate, the is 20 g/kg. It is an irritant to the eyes and can cause blindness.