... added to the system, and the time and results of measurements of free residual chlorine (FRC) and pH. Shock-treat cooling tower water at 50 -ppm FRC. Use fast-release, chlorine-containing disinfectant ... used for disinfection and aerosolized water-containing Legionella. Protective equipment may include full-length protective clothing, boots, gloves, goggles, and a full- or half-face mask that ... 326, 151 – 155 , 1992.Williams, J.F. et al., Microbial contamination of dental unit waterlines: prevalence, intensity and microbio-logical characteristics, J. Am. Dental Assoc., 124, 59 – 65, 1993.Wisconsin...