Calcium hypochlorite is commonly used to sanitize public swimming pools and disinfect drinking water. Chlorine dioxide may be used to disinfect poultry by spraying or immersing it after slaughtering. Chlorine is ubiquitously added to drinking water to disinfect it. The term sanitizer has been used to define substances that both clean and disinfect. Sanitizers are substances that simultaneously clean and disinfect. Western mugwort smoke was used to disinfect contaminated areas and revive patients from comas. People with dentures should also disinfect their dentures regularly to prevent oral candidiasis. Hot water is used to disinfect respiratory and anesthesia equipment. Consequently, the population was warned to boil or otherwise disinfect water to prevent disease. Brass and copper, for example, disinfect themselves of many door handle bacteria within eight hours. Microbiology laboratories use UVGI to disinfect surfaces inside biological safety cabinets ("hoods") between uses. Historically it was used to disinfect drinking water and can turn the water pink. In addition, salt was used to disinfect wounds. Lab personnel also disinfect glassware and plasticware this way. Following scaling, additional steps may be taken to disinfect the periodontal tissues.