A portable device for mixing a dilute disinfectant solution comprising a first reservoir comprising a predetermined amount of said disinfectant solution, a chamber which is connected to said first reservoir and which holds a predetermined amount of dilutant, and means for discharging said predetermined amount of said disinfectant solution from said first reservoir into said chamber to be mixed with said predetermined amount of dilutant in said chamber wherein said device provides the dilute disinfectant solution at a fixed dilution determined by the ratio of the predetermined amount of said disinfectant solution to the predetermined amount of dilutant.