These requirements cover electrically operated water treatment appliances for household and commercial use. These appliances are intended for installation and use in accordance with the National Electrical Code@ NFPA 70@ and are rated 600 V or less. These requirements cover appliances utilizing features that treat water through the use of cation exchange water softeners@ ionization@ filters@ ultraviolet radiation@ ozone generation@ and reverse osmosis. These requirements do not cover water treatment appliances for use with pools or spas@ water distillers@ aquariums@ or other equipment connected to plumbing that is covered by individual requirements. These requirements do not cover appliances for use in hazardous locations as defined in the National Electrical Code@ NFPA 70. These requirements do not cover the aesthetic effects or the effectiveness of water treatment.