Assesses the efficacy of three glycol vapors (propylene glycol, dipropylene glycol, and triethylene glycol) against inactivation of two pathogen surrogates (Bacillus subtilis and MS2 bacteriophage) under laboratory-controlled conditions using a purpose built-experimental chamber to control for microbiological and environmental variation. Variables to be evaluated include four different dispersion methods, five indoor relative humidity setpoints, and three different concentrations (sub-saturation, near-saturation, and super-saturation).