Activated hydrogen peroxide disinfecting compositions are provided especially for low-foaming applications. A concentrate for dilution by an end-user is provided, which includes a hydrogen peroxide source, a non-surfactant organic sulfonic acid or salt thereof, a non-ionic surfactant, and an optional organic acid. Also provided is a ready-to-use hydrogen peroxide, disinfectant solution including a biocidal amount of hydrogen peroxide, a non-surfactant organic sulfonic acid or salt thereof, a non-ionic surfactant, water as solvent and an optional organic acid. An end-user can disinfect a surface of microorganisms by contacting the surface with the disinfecting composition for an amount of time effective to kill a majority of the microbes located on the surface.