Plumbing Africa November 2017 | Page 31

HEALTH AND SANITATION 3 2 1 29 abrasion and re-contamination • Natural oxidation does not impair efficacy 3. Safe to use • Not harmful to people or the environment (sustainable and ‘green’) • Inherently antimicrobial, no chemicals added • Completely recyclable. 1. 4 2. 3. 4. This should be enough to digest for this issue, as there is much to read in Part 2. PA Antimicrobial brass door handle fitted within health care buildings. Antimicrobial brass mixer for health care built environment applications. Antimicrobial paraplegic grab rail for paraplegic installations. An example of antimicrobial copper overtable in a hospital ward bathroom. Legionella control with chlorine treatment Chlorine and chlorine-based compounds are disinfectants that can serve the dual role of efficiently inactivating microorganisms during water treatment, as well as maintaining the quality of the water as it flows from the treatment plant to the consumer’s tap. By By Environmental Protection Agency, document EPA 810-R-16-001 Numerous studies have demonstrated that chlorine effectively kills many disease-causing bacteria and other pathogens (McGuire, 2006). Chlorine is added to drinking water as elemental chlorine (chlorine gas), sodium hypochlorite solution or dry calcium hypochlorite. Due to safety issues with chlorine gas, many US water systems have switched to sodium hypochlorite for disinfection (McGuire, 2006). Chlorine can be applied by facilities for routine treatment of both hot and cold domestic water; it can be applied to www.plumbingafrica.co.za the cold and hot water tanks, or to the entire distribution system. However, free chlorine degrades rapidly in hot water systems (Health Protection Surveillance Centre, 2009). Chlorine can also be used at high doses for emergency disinfection of potable water systems through shock chlorination (also called shock hyperchlorination). For chlorine to be effective against microorganisms, it must be present in sufficient concentration, and must have adequate time to react. Continued on page 31 >> November 2017 Volume 23 I Number 9