Decontamination in primary care dental practices - Gov.uk

Decontamination: Health Technical Memorandum 01-05 – Decontamination in primary care dental practices (2013 edition)• a basis for recording the maintenancerequirements;• a basis for recording and accessing informationassociated with disinfection and maintenance.19.31 When completing records, it is essential that theindividual concerned signs and dates the entries,and that there is an audit trail in place.Water supply hygiene19.32 After any installation work, all piping, fittings andassociated services used for the conveyance ofwater for domestic purposes must be disinfectedbefore being brought into use. The methodgenerally used for disinfection is chlorination.Disinfection using chlorine should be carried outin accordance with BS EN 806-2:2005, BS EN806-3:2006 and BS 8558:2011 (see also HealthTechnical Memorandum 04-01 Part A Chapter17) and under the direct supervision of anominated person.19.33 Despite disinfection of systems, some outbreaks ofdisease related to treated water supplies still occur.To reduce the risk of such outbreaks, the designshould eliminate:• direct contact with the internal parts of waterpipes and structures by people, animals or birds(for example, ensure covers are in place onstorage tanks/cisterns);• backflow (back-siphonage) of contaminatedwater into systems conveying potable water(mains and storage structures).Water treatment19.34 In a properly installed and commissioned hotwater system, it should be possible to maintain atemperature of at least 55oC at the furthest drawoffpoint in the circulating system, and 50oC inthe circulating system’s return connection to thecalorifier.19.35 In older premises, however, this may not bepossible, and in the case of cold water systems itis not always possible or practicable to maintainwater temperature below 20oC because ofutilisation and complexity. In addition, therefore,it may be necessary to apply a residual biocidalwater treatment that has been shown to destroyand remove biofilm. Information on thesetechniques, which include chlorine dioxide andcopper and silver ionisation, can be found inHealth Technical Memorandum 04-01 Part B.NoteIn addition to residual biocidal techniques, thereare other manufacturer-specified treatments that aredeveloped for use on DUWLs and other associateddental equipment. Refer to the manufacturer’sinstructions for their correct use.19.36 Where automatic equipment is used fordisinfection, it should indicate any change in theamount or concentration of material injected intothe water so that immediate action can be taken.19.37 Continuous dosing with appropriate biocides thathave proven efficacy should be considered duringconstruction to prevent the accumulation ofbiofilm. A regular flushing programme for alloutlets should also be implemented.19.38 The continuous chlorination of hot and cold waterservice systems to control the growth of Legionellais not generally recommended. Advice on the useof biocides should be sought from the personadvising the practice on Legionella.19.39 In defining their responsibilities, service providersshould be asked to advise on test methods andanticipated concentrations of residual chemicalswithin the system. (See also Chapter 3 of HealthTechnical Memorandum 04-01 Part A for moreguidance on water treatment regimens.)Purging the systems19.40 Where chemical treatment is introduced, it isessential to ensure that all parts of the systemare purged so that adequate concentrations areachieved.19.41 As temperature monitoring is performed onsentinel and representative outlets on a rollingbasis only, additional draw-off will be required atall points on a regular basis.Ozone and ultraviolet treatment19.42 Whereas treatments such as chlorine dioxide andcopper and silver ionisation are intended to bedispersive (that is, they result in a residual agentwithin the system), ozone and ultraviolet areintended to be effective close to the point ofapplication. They are not, therefore, necessarilyeffective in hot and cold water service systems (seeChapter 15 of Health Technical Memorandum04-01 Part A).70