HTM 64 Healthcare Standard

 

This is one of a series of Health Technical Memoranda which provides specification and design guidance, not adequately covered by current British Standards, on building components for health buildings.

The guidance given in this Health Technical Memorandum applies to all new capital projects and whenever refurbishment or repair is required to existing facilities.

Suppliers offering products other than to British Standards should provide test evidence to show their products are at least equal to such standards.
Reference should also be made to the acceptabilityof water fittings as approved by the Water Regulations Advisory Scheme (WRAS) and published in the ‘Water Fittings and Materials Directory’ (http://www.wras.co.uk).

Terminology
Throughout this Health Technical Memorandum the following definitions apply:
General pattern: for use by hospital staff, patients and the public in general, that is, nonclinical use.
Hospital pattern: for use by clinical staff in connection with clinical procedures.

Sanitary assembly: an assembly comprising a soil or waste appliance and appropriate supply and waste fittings.
Soil appliance: an appliance for the reception and discharge of excretory matter.
Supply fitting: a fitting to control or regulate the supply of water, commonly used with an appliance.
Waste appliance: an appliance for the reception of water for ablutionary, cleansing, or culinary purposes and its discharge after use.
Waste fitting: a fitting to conduct the discharge from an appliance and to connect to pipework.

WCs
 Hospital pattern WCs should be rimless, washdown pans and be of the “back-to-wall” or “wallhung” type with concealed cistern and services.
Access for sanitary chairs and wheelchairs should be carefully considered. This will involve coordinating the dimensions of chairs with those
of WC assemblies and any necessary adjustment to the location of the WC in relation to the wall behind it, or to the height from floor level, to facilitate transfer of patients to and from the chair. The Building Regulations require adequate provision of accessible WC facilities: consideration will be required for suitable provision of such facilities in general areas where they may be used by visitors.  For further information, refer to Health Building Note 40 Volume 1, Section 2 – ‘Sanitary spaces’,the Building Regulations Approved Document Part M, and BS 4751 ‘Mobile sanitary chairs’. All pans should have a horizontal or P-outlet so that the soil pipe can be connected above floor level. This gives flexibility in setting out pans and pipework and allows access to the joint for both
installation and maintenance. A variety of WC connectors are available which can accommodate different configurations between the outlet and the soil pipe (see BS 5627:1984‘Specification for plastics connectors for use with horizontal outlet vitreous china WC pans’).  Suitable access should be provided to allow the fitting of the WC connector to be carried out properly. This can be provided either from the rear within a duct or by access panels on the room side.
Flushing arrangements are traditionally lever operated. However, dual-flush, anti-vandal pneumatic push-buttons, flush plates or sensor
operation could also be considered.

Disposal units
2.4 A hospital pattern disposal unit should be provided in clinical areas for the disposal of solid and liquid waste, and the contents of vomit bowls,
drainage bags and urine bottles.
2.5 The unit can also act as a standby in the event of the failure of a bed-pan disposal unit (macerator)

Urinals
Bowl urinals are more hygienic and easier to install than slabs. Assemblies of one, two and three bowls are available in the hospital pattern assembly with concealed services and cistern. Water economy should be considered when choosing urinals.  Additionally, waterless urinals could be considered.Using an appropriate cleaning regime, waterless urinals can eliminate all supply services (resulting in better hygiene), reduce duct depth and eliminate the splashing, spray and medium for bacteria associated with water-fed urinals.

Basins
Basins should have a smooth form and easilycleaned surfaces. Overflows should not be provided for infection control reasons. Three sizes of basin should fulfil most of the user requirements in health buildings: • large basins: for use in clinical areas for “scrub-up” purposes, and for use by seated or wheelchair patients, for which wide shallow basins should be selected;

• medium basins: for use in clinical procedures and in general areas/domestic services;
• small basins: for use inside WC cubicles/stalls,food preparation areas and similar locations.

Suitable only for hand-rinsing.

Hospital pattern
Hospital pattern basins should be used in clinical procedures with safe, integral thermostatically (TMV3 D08) controlled water and wall-mounted single lever-action or sensor taps with concealed/ducted services. Areas. (See also Health Facilities Note 30 – ‘Infection control in the built environment’, which gives additional guidance on basin design). General pattern basins with tap-holes should be used for general areas/domestic services with thermostatically (TMV3 D08) controlled maximum hot water temperature and concealed/ducted services. Washing is in a reservoir of water; therefore a bowl with plug is recommended. Plugs should be attached to an open-link chain which should be panel-mounted. Where medium or small basins are selected with a monobloc pillar mixer tap (TP6), the basin should be specified with a single 35 mm tap-hole.

Basin selection
When selecting taps for clinical procedures, and certain activities in food-preparation and laboratory areas, supply fittings will be required that can be operated without the use of hands. Fittings actuated by a proximity sensor are now an alternative to lever-action taps.

Baths
General baths (that is, baths used for non-assisted personal bathing) have no tap-holes and should be used with wall-mounted mixer taps offering a safe, thermostatically (TMV3 D08) controlled maximum temperature. Mechanically-operated variable-height baths are recommended for assisted bathing. These types of  bath are not covered in this guidance. See Health Building Note 40 for spatial requirements, size and position of components used in assisted bathing.

Scrub-up troughs
Scrub-up troughs should be provided to enable one or more surgeons and nurses to scrub their hands and forearms.  Troughs should be wall-hung and fitted with a single waste outlet. Taps should be wall-mounted and deliver safe, thermostatically (TMV3 D08) controlled hot water. Sensor-controlled fittings are ideally suited to control the flow of water at scrub-up troughs and can offer the additional benefit of controlled run times. The relationship between the taps and the trough is critical in order to avoid splashing.

Sinks and sinktops
2.47 A range of single-bowl and double-bowl sinks with or without integral drainers and/or worktops are available. They should have a smooth form and easily-cleaned surfaces. Overflows are not provided, as they are unhygienic. Sinks and sinktops are available in various sizes and materials to suit the recommendations in this Health Technical Memorandum and the specific dimensional recommendations of Health Technical Memorandum 62 – ‘Demountable storage systems’, Health Technical Memorandum 63 – ‘Fitted storage systems’ and Health Technical Memorandum 67 – ‘Laboratory fitting-out systems’. Sinks with integral tops are available in a variety of materials as well as stainless steel, and the appropriate material should be selected to reflect the intended use.

Water conservation
The need to conserve water should always be considered when selecting sanitary assemblies and supply fittings.  Considerable savings of both hot and cold water can be made by specifying showers rather than baths and taps that include flow regulation or selfclosing for hand-rinsing. Use of compliant dualflushing
WC cisterns and waterless urinals in public general toilet areas constitutes a major contribution to water saving.

Pipework
Pipework should be planned to avoid dead-legs which become stagnant. This is hazardous, as it can create conditions suitable for organisms like Legionella to multiply. In addition, they are wasteful of heat and can cause corrosion of pipes and fittings by allowing sediment to be deposited. Isolating valves should be provided to isolate each individual appliance.  Pipe clips on exposed pipework should be specified and installed to avoid injury to staff and patients from sharp edges or the like.

Water pressure
As far as possible, the engineering services installation should be designed to ensure minimum pressure differential between hot and cold water supply pipes at the point of connecting the control fitting; this will improve the performance of sanitary assemblies, helping to avoid the use of expensive supply fittings such aspressure-regulating valves.

Water temperature
The water temperature at point of delivery should be controlled by one of the methods described below as appropriate to user requirements. Provided certain requirements are met (notably that hot and cold pressures are balanced and from HTM 64: Sanitary assemblies 6 a common source, and that the outlet air gap is appropriate), the Water Fittings (Water Supply) Regulations permit blending within the supply fitting.

Water delivery
The control of water delivery at point of use – on/off and hot/cold – may be achieved in several ways and in several different combinations. Supply fittings are more normally controlled by hand manipulation of a tap head, which may be press-down-shroud or a lever. Fittings are now available in which the flow of water is initiated by means of a sensor switch. Such devices may well have considerable application in high-risk areas such as operating
theatres and burns units; they can also be effective in reducing water waste. Other fittings are now available in which the flow of water is initiated and terminated by an integral,thermostatic single lever.

Manual control
Separate hot and cold water taps or valves are controlled manually by the user.

Individual thermostatic control
Thermostatic mixing of hot and cold water is by a valve at a fitting. The maximum water temperature required may be set and locked on the valve.
The design team should refer to Health Technical Memorandum 04 when considering the problems of safety, particularly the risk of scalding young children and older people. To reduce the risk of an outbreak of Legionnaires’ disease occurring, cold water should be stored and distributed at a temperature below 20°C and hot water should be stored at a temperature of a minimum of 60°C and distribution controlled to a temperature of a minimum of 55°C.
The safety of users, particularly some children and older people, would be compromised if they were allowed to use washing or bathing facilities supplied with water at this temperature (that is, immersion in, or exposure to, running hot water). This risk can be reduced by the installation at each hot outlet of a locally adjustable thermostatic mixing valve (see Health Technical Memorandum 04 for guidance on safe water temperatures). Valves of this type are unaffected by changes in water pressure and should automatically and quickly close the hot or cold supply if either supply fails. Vigilance will still be required to ensure thatvulnerable patients using sinks in kitchens are not in prolonged contact with water which could be in excess of these temperatures.

Water delivery
 The control of water delivery at point of use –on/off and hot/cold – may be achieved in several ways and in several different combinations. Supply fittings are more normally controlled by hand manipulation of a tap head, which may be press-down-shroud or a lever. Fittings are now available in which the flow of water is initiated by means of a sensor switch. Such devices may well have considerable application in high-risk areas such as operating theatres and burns units; they can also be effective in reducing water waste. Other fittings are now available in which the flow of water is initiated and terminated by an integral, thermostatic single lever.

Positioning supply fittings
Supply fitting services should be concealed. Consideration should be given to fittings that can be serviced/maintained without the need to remove any panels.

Back-siphonage
Water regulations now differentiate the level of back-siphonage protection required by the class of risk associated with the receiving vessel. As a general rule, hospital applications of even domestic ablutionary arrangements are elevated to class 4 or class 5 risk and as such, require that supply fittings on baths, basins and sinks etc with fixed outlets shall be arranged so that the discharge point creates an AUK3 air gap of twice the inlet diameter and never less than 25 mm above the spill-over level of the appliance. Concealed showers with fixed-position adjustable heads are recommended, but when flexible hoses with sliding and hand-held spray attachments are unavoidable, special measures must be taken to prevent back-siphonage. The proximity of any adjacent sanitaryware should be considered. The ‘Water Regulations Guide’ is the best source of information on this issue.

Waste fittings
 The waste fittings included in this Health Technical Memorandum are outlets and traps.
 All outlets are unslotted for use with appliances without overflows. There are two types: one with a flush grating and the other with a recessed grating, plug, chain and stay. Plugs are recommended only where it is necessary to retain water in an appliance, that is, basins for general use, baths and sinks. Where this is not recommended, plugs should be omitted and the flush-grating type used.  Bottle traps for use with waste appliances should be plastic with a white finish.

Concealed services
In clinical areas, pipework and cisterns should always be concealed.  Exposed services are visually unattractive, can be unhygienic, and are difficult to clean and decorate. Indeed, the additional cost of the latter over a number of years may well exceed any savings in initial capital costs. In all cases, the objectives of design and specification should be an installation which is neat, easy to clean and maintain, and durable.

Bacterial growth
Components and accessories should not sustain the growth of bacteria. The design team should refer to Health Technical Memorandum 04 and Health Facilities Note 30 for guidance on the control of Legionella and other bacteria.

Fixings and loadings
 All appliances should accept live loadings in use. This depends on the strength of the appliance, its fixing devices and the construction to which it is fixed. A load of 140 kg should be sustained by the assembly.