1、BRITISH STANDARD BS3970-5: 1990 Sterilizing and disinfecting equipment for medical products Part 5: Specification for low temperature steam disinfectorsBS3970-5:1990 This British Standard, having been prepared under the directionof the Health Care Standards Policy Committee, waspublished under the a
2、uthorityof the Board of BSI andcomes into effect on 28 September1990 BSI03-1999 The following BSI references relate to the work on this standard: Committee referenceHCC/14 Draft for comment85/53989DC ISBN 0 580 18508 7 Committees responsible for this British Standard The preparation of this British
3、Standard was entrusted by the Health Care Standards Policy Committee (HCC/-) to Technical CommitteeHCC/14, upon which the following bodies were represented: Associated Offices Technical Committee Association of British Health-Care Industries Association of British Sterilizer Manufacturers Associatio
4、n of Clinical Pathologists Association of National Health Service Supplies Officers British Dental Trade Association British Surgical Trades Association Central Sterilising Club Department of Health Guild of Hospital Pharmacists Health and Safety Executive Infection Control Nurses Association Instit
5、ute of Hospital Engineering Institute of Purchasing and Supply Institute of Sterile Services Management Joint Committee of Professional Nursing, Midwifery and Health Visiting Associations (England) Medical Sterile Products Association National Blood Transfusion Service Public Health Laboratory Servi
6、ce Regional Hospital Boards Engineers Association Royal College of Pathologists Royal Pharmaceutical Society of Great Britain Scottish Health Services Stainless Steel Fabricators Association of Great Britain Amendments issued since publication Amd. No. Date of issue CommentsBS3970-5:1990 BSI 03-1999
7、 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 General requirements 1 4 Design pressure 1 5 Operating cycle 1 6 Instrumentation and controls 2 7 Performance requirements 3 Appendix A Chamber temperature test 4 Appendix B Air ingress monitor test 4
8、Appendix C Small load test 4 Appendix D Full load test 5 Appendix E Load dryness test 5 Appendix F Leak rate test 6 Appendix G Over-temperature cut-out test 6 Publications referred to Inside back coverBS3970-5:1990 ii BSI 03-1999 Foreword It is recommended that this foreword be read in conjunction w
9、ith the foreword of BS3970-1. This Part of BS3970 has been prepared under the direction of the Health Care Standards Policy Committee. It forms part of BS3970, which specifies requirements for a range of sterilizing and disinfecting equipment intended for medical and related uses. The general requir
10、ements applicable to all the sterilizers and disinfectors covered by this standard are given in Part1. Those requirements that are not common to most types of sterilizer or disinfector are specified in subsequent Parts of BS3970. These Parts, giving particular requirements, should be read in conjunc
11、tion with BS3970-1:1990 which they supplement or modify. The titles of these Parts are expected to be as follows: Part 3: Specification for steam sterilizers for wrapped goods and porous loads; Part 4: Specification for transportable steam sterilizers for unwrapped instruments and utensils; Part A 1
12、) : Specification for steam sterilizers for fluids in sealed rigid containers; Part B 1) : Specification for steam sterilizers for fluids in unsealed vented containers; Part C 1) : Specification for steam sterilizers for fluids in sealed non-rigid containers; Part D 1) : Specification for sterilizer
13、s using low-temperature steam with formaldehyde; Part E 1) : Specification for sterilizers using ethylene oxide or ethylene oxide mixtures. This Part specifies requirements, in addition to those specified in BS3970-1, for equipment operating at sub-atmospheric pressures and designed to disinfect hea
14、t sensitive products by using saturated steam at low temperature in the absence of formaldehyde (see note). The process described achieves disinfection only. The equipment specified in this Part of BS3970 is intended for treating both wrapped or unwrapped instruments and for those materials unsuitab
15、le for treatment at temperatures above80 C. Only one operating cycle is specified; process control is fully automatic. It is necessary to ensure that the walls of the chamber are heated prior to commencing stage2 in order to minimize condensation and to achieve the correct conditions for disinfectio
16、n. Also, for successful disinfection, it is usual to have an efficient vacuum system both to ensure steam penetration during stage5 of the operating cycle and to ensure that the pressure during stage6 is sufficiently reduced to enable the moisture to be removed from the load (seeclause5). NOTEAlthou
17、gh this practice is deprecated, the operating cycle specified in this standard is usually provided as an alternative operating cycle on equipment designed for sterilization by low temperature steam with formaldehyde. It is for this reason that this Part is included in BS3970. The Part of BS3970 spec
18、ifying low temperature steam sterilizers using formaldehyde is being considered at the time of publication of this Part of BS3970. Attention is drawn to the fact that the production of dry packs is assisted by the use of suitable absorbent packaging materials. Guidance in the treatment of wet loads
19、is given in Health Technical Memorandum (HTM) 10 “Sterilizers”, published by the Department of Health and Social Security. 1) In preparation; each Part will be allocated a number in its respective order of publication.BS3970-5:1990 BSI 03-1999 iii Product certification. Users of this British Standar
20、d are advised to consider the desirability of third party certification for product conformity with this British Standard, based on testing and continuing surveillance which may be coupled with assessment of a suppliers quality systems against the appropriate Part of BS5750. Enquiries as to the avai
21、lability of third party certification schemes will be forwarded by BSI to the Association of Certification Bodies. If a third party certification scheme does not already exist, users should consider approaching an appropriate body from the list of Association members. Alternatively, users of this Br
22、itish Standard may wish to consider the desirability of assessment and registration of a suppliers quality systems against the appropriate Part of BS5750 by a third party certification body. A British Standard does not purport to include all the necessary provisions of a contract. Users of British S
23、tandards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi toiv, pages1to8, an inside back cover and a back cover. This sta
24、ndard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.iv blankBS3970-5:1990 BSI 03-1999 1 1 Scope This Part of BS3970 specifies particular requirements for disinfectors using a single specified ope
25、rating cycle and using mains supplied steam. These requirements apply in addition to the general requirements specified in BS3970-1. The disinfector specified is applicable to the disinfection of heat labile materials (see foreword). NOTE 1It is emphasized that equipment complying with this Part of
26、BS3970 is only designed to disinfect (see2.2). NOTE 2The titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this Part of BS3970, the definitions given in BS3970-1 apply, together with the following. 2.1 low temperature steam
27、 pure water vapour in equilibrium with liquid water at a temperature below100C NOTEIn practice, low temperature steam refers in this Part of BS3970 to water at its boiling point at an absolute pressure of350mbar 2)or 35kPa. This pressure corresponds to approximately73 C. 2.2 disinfection the process
28、 used to reduce the number of viable micro-organisms in a load but which may not necessarily inactivate some viruses and bacterial spores NOTEThe disinfection process may not achieve the same reduction in microbial contamination levels as sterilization. 3 General requirements 3.1 Disinfectors shall
29、comply with the requirements of BS3970-1, and with3.2 and clauses4 to7 of this Part of BS3970. NOTEUsers of this Part of BS3970 are advised that reference should be made to The Electrical Safety Code for Hospital Laboratory Equipment (ESCHLE) as certain of its requirements are specified in BS3970-1.
30、 3.2 Unless otherwise stated in this British Standard, compliance with this Part of BS3970 shall be checked by visual inspection and, if appropriate, by direct measurement. 4 Design pressure The design pressure of the vessel shall permit its operation within the gauge pressure range1 bar to0.2bar 2)
31、 . The design pressure of the jacket, if fitted, shall be within the same limits. 5 Operating cycle 5.1 Cycle stages The disinfector shall perform the following operating cycle with a load of mass not exceeding170kg for each cubic metre of the usable chamber space. if in any of the following stages
32、the specified conditions are not achieved, a fault shall be indicated. a) Stage 1: Pre-heating. Before stage2 can commence, the walls of the chamber shall be at a temperature of71 C to78 C (see7.1). b) Stage 2: Air removal. Sufficient air shall be removed from the chamber and the load to permit atta
33、inment of the disinfecting conditions (see7.2 and7.3). c) Stage 3: Air ingress monitoring. Means shall be provided to monitor the ingress of air into the chamber commencing when the pressure in the chamber is at its lowest value. If the rate of pressure increase is greater than5mbar/min, the operati
34、ng cycle shall proceed directly to stage6. (See7.5.) d) Stage 4: Steam admission. Steam shall be admitted to the chamber until the temperature attained throughout the load (see7.2 and7.3) is73 2 C. e) Stage 5: Disinfection. During this stage the temperature throughout the chamber and the load shall
35、be not less than the nominal disinfecting temperature73 C for a period of not less than10 min. The chamber temperature, measured at the active chamber discharge, shall be controlled at73 2 C during this stage. In addition, after the first5min of this stage and until the conclusion of this stage, the
36、 temperature of the chamber wall shall be not lessthan the temperature of the active chamber discharge. (See7.1, 7.2 and7.3.) f) Stage 6: Drying. Steam shall be extracted from the chamber, and the chamber pressure shall be reduced sufficiently to permit the evaporation of condensate from the load ei
37、ther by prolonged evacuation of the chamber or by the injection and subsequent extraction of heated air or other gases within the chamber (see7.4). If the load is dried without the injection of hot gases, the duration of the drying stage shall be not less than3 min and the chamber pressure at the en
38、d of stage6 shall be not greater than40mbar absolute. 2) 1bar=10 5 N/m 2 =10 5 Pa.BS3970-5:1990 2 BSI 03-1999 If the load is dried by injecting heated gases into the chamber, the gases shall be filtered (seeclause 15 of BS3970-1) and the temperature of the injected gas shall not exceed80 C; the dura
39、tion of the drying stage (stage6) shall be not less than3min and the chamber pressure at the end of stage6 shall attain40mbar absolute or less. g) Stage 7: Air admission. Air shall be admitted to the chamber through the filter (see clause 15 of BS3970-1) until the chamber pressure is within100mbar o
40、f atmospheric pressure. The duration of the specified overall cycle time (stage2 to stage7 inclusive) shall not exceed60min (see note). NOTEThe specified overall cycle time includes the drying, i.e.stage6, that is required to achieve a dry load with the test load described in Appendix C. However in
41、practice, other loads may be more difficult to dry and thus are likely to require extended drying times (see6.1.2) leading to an extension of the overall cycle time. Compliance is checked by inspection and as described in Appendix A, Appendix B, Appendix C, Appendix D and Appendix E. 5.2 Leak test c
42、ycle The disinfector shall be provided with the facility for a leak test cycle under the control of the automatic controller. Selection of this cycle shall only be accessible to the operator by means of a special key, code or tool. NOTE 1The leak test cycle may be incorporated by modification of sta
43、ge2, stage3 or stage6 of a normal operating cycle. If the leak test cycle is achieved by modification of stage2 or stage3, the leak test cycle may exclude stages4 to7 inclusive of the normal operating cycle. Selection of the leak test cycle shall initiate the following operations carried out in sequ
44、ence with no load in the chamber. a) The pressure in the chamber is reduced to lessthan40 mbar. (See also note toB.2.1.) b) All the valves directly connected to the chamber are closed. c) Either the vacuum pump is stopped or, if the vacuum source is external to the machine, a second valve isolating
45、the evacuated chamber is closed. d) The isolating valve, if fitted between the chamber and the absolute pressure gauge, is opened and remains open for a period of not lessthan15 min and not more than20 min, theperiod being monitored by a leak test timer (seeAppendix B). e) After this period, air is
46、admitted to the chamber through the filter (see clause15 of BS3970-1) until the chamber pressure is within100mbar of atmospheric pressure. There shall be an indication, visible to the operator, when the leak test timer is operating. At the end of the leak test cycle the automatic controller shall in
47、dicate a “FAULT”. NOTE 2The automatic controller may also indicate that the leak test cycle has been completed. Compliance is checked as described in Appendix F. 6 Instrumentation and controls 6.1 Instruments and control equipment additional to that specified in BS3970-1 6.1.1 If an indicating therm
48、ometer is fitted to monitor the temperature of the chamber wall, the sensor for this thermometer shall be attached either to the chamber wall or, if a jacket is fitted, within the jacket space. 6.1.2 A system for controlling additional drying time shall be fitted to enable stage6 to be extended by20
49、min or less (seenote to5.1). 6.1.3 A monitoring timer shall be fitted so that if the combined time for stages4 and5 exceeds the disinfection time (stage5) by more than3 min, a fault is indicated. 6.1.4 A leak test timer shall be fitted, capable of indicating periods of at least20min to an accuracy of 10s. 6.1.5 Over-temperature cut-outs shall be fitted, in addition to those specified in BS3970-1. These cut-outs shall ensure that the chamber wall and the chamber free space will not exceed80 C. The cut-outs shall effect this by disconnecting the s
