Research leading to the development of Sporicidin, a new (synergized glutaraldehyde-phenate) sterilant and concentrated disinfectant, is reported. Microbial evaluation and shelf life testing of the new formulation was done using AOAC tests—Use-Dilution, Sporicidal, Tuberculocidal—and the E.P.A. Virucidal Test. Full-strength Sporicidin sterilizes (is sporicidal) in 6% hours at both 20C and 25C, and disinfects in 1-2 minutes. When diluted with 15 parts of tap water, Sporicidin is tuberculocidal, virucidal, and germicidal in 10 minutes, qualifying as a hospital disinfectant that will not “yellow” the hands or skin. The shelf life of activated Sporidicin, full strength or diluted 1 in 16, is 30 days. According to the data presented, which were the basis of E.P.A. registrations, Sporicidin is: (a) the fastest glutaraldehyde sterilant at room temperature, and (b) the only glutaraldehyde product that can be diluted below 2% and still qualify as a hospital disinfectant.