Recently, a significant amount of attention has been directed toward development of novel classes of biocides because of the potential for microbial contamination and infection risks to military personnel and in the general population. We have recently discovered a new and unexpected class of powerful biocides based upon compounds derived through simple chemistry from silicone intermediates, "silicon alcohols" called, silanols. One example is trialkylsilanols, R3SiOH. Antimicrobial tests were carried out against Gram-negative bacterium, Escherichia coli, and Gram-positive, Staphylococcus aureus, with silanols, t-butanol, and siloxanes. Trialkylsilanols were very effective biocides against Escherichia coli and Staphylococcus aureus. The number of viable bacteria reduced was more than eight orders of magnitude with silanol treatments. Triethylsilanol, in particular, exhibited a strong antimicrobial effect at a very low concentration within 10 min. These novel biocide silanols can be prepared from low cost intermediates derived from the commercial processesassociated with the silicone industry. Silanols are considered environmentally benign because of their transitory nature and ultimate conversion to CO2, SiO2, and H2O.