1、AECMA STANDARD NORME AECMA AECMA NORM Edition approved for publication 30 September 2004 prEN 4618 Edition P 1 September 2004 Comments should be sent within six months after the date of publication to AECMA-STAN PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES - STANDARDIZATION d%k? the
2、se are given in the table below. However, the concentrations below are not indicative of the risk of acquiring infection in susceptible individuals. Table B.l - Environmental categories for mixed populations of fungi and bacteria in non-industrial indoor environments ref I Low I 100 I 100 Intermedia
3、te I 500 I 500 References I Wanner H-U, Verhoeff A, Colombi A, Flannigan B, Gravesen S, Mouileseaux A, Nevalainen A, Papadakis J and Seide K. Biological particles in Indoor Environments. European Collaborative Action, Indoor air quality and its impact on man. Commission of the European Communities,
4、Luxembourg, 1993. 2 Guidelines workplace, Germany according EU-frame-guidelines 89/391; BIAs report 2/95 Indoor Air Quality, Germany B.1.3 Comfort Acute exposure to micro-organisms is not a comfort issue. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under
5、 license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 28 prEN 4618:2004 B.2 Measurement Method Measurement should be taken at the air exit from the individual air outlets (if these are fitted) or at the air inlets to the cabin. Measurement method
6、using MB2 Microbiological Aerosol Samplers to take air sample onto an agar plate for sending to a laboratory. For additional information regarding the current technological solution for the removal of bacteria and viruses, please refer to Annex C. Copyright Association Europeene des Constructeurs de
7、 Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 29 prEN 4618:2004 Annex C (informative) Technical information for bacteria, viruses and other particulate contamination removal C. 1 I nt rod u cti o
8、n This standard is performance based and not solution based, therefore the technologies for removing bacteria, viruses and other particulate matter have not been addressed in the main part of this standard. C.2 Cabin Air Recirculation System In the majority of modern commercial aircraft, the air sup
9、plied into the cabin via the environmental control system (ECS) uses a mixture of outside air and recirculated air. Air for recirculation can be taken from the general space above the passengers, from the cabin outlet, or from the air volume under the cabin floor The cabin air recirculation system s
10、hall ensure that the levels of particulate contamination re-entering the aircraft cabin are below the levels defined in this standard and not worse than the external ambient conditions, outside of the aircraft Currently, the levels defined for bacteria, fungi and virus micro-organisms and the levels
11、 defined for particulate contamination may be achieved by the installation of HEPA filter elements (equal to or greater than EU grade H13) on the recirculation air line within the environmental control system. This level of filter element removal efficiency shall effectively prevent transmission of
12、diseases through the recirculation system by stopping airborne pathogenic microbes (microbes include bacteria and viruses) on the first pass. Note that these cabin air recirculation filter elements do not prevent the possibility of direct person to person transmission within the aircraft cabin. NOTE
13、 HEPA filter = High Efficiency Particulate Air filter, classes HI0 to HI4 (85 % to 99,995 % efficiency) As defined in European Standard EN 1822-1 :I 998 For aircraft cabin air recirculation systems, this definition has been tightened and the typical aerospace industry standard for new build producti
14、on aircraft is EU Class H13, .e 99,99 % minimum removal efficiency by sodium flame test (Eurovent 4/4, BS3928). This is equivalent to 99,97 % minimum removal efficiency at 0,3 pm when tested according to IEST Recommended Practice RP-CC001.3 ?HEPA and ULPA Filters? (IEST, Institute of Environmental S
15、ciences and Technology 1997). C.3 Independent references I The World Health Organisation (www.who.int), ?Summary of SARS and air travel?, dated 23 May 2003. 2 The World Health Organisation (www.who.int), ?Tuberculosis and Air Travel?, dated 1998 3 The SAE Aerospace Information Report AIR 4766 - ?Air
16、 Quality for Aircraft Cabins?, 4 The UK House of Lords Report, ?Air Travel and Health?, dated November 2000. 5 Centers for Disease Control , ?Guidelines for Preventing the Transmission of Mycobacterium Tuberculosis in Health-Care facilities, 1994, Copyright Association Europeene des Constructeurs de
17、 Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 30 prEN 4618:2004 Annex D (informative) Measurement method for micro-organisms D. 1 Introduction If desired, measurements can be carried out according
18、 to the methods described below. D.2 General Bacteria are classified as prokaryotic micro-organisms, while fungi are eukaryotic micro-organisms. Both are ubiquitous in nature and play an important role in the natural cycle of matter by breaking down and mineralising organic material. Bacteria/fungi
19、occur in various human workplaces and communal areas, and may sometimes reach air concentration levels, which are considerably higher than reference values in outside air. Bacteria/fungi occur as single cells or cell aggregates and are often bound up in dust particles or suspended in droplets. The t
20、ypical diameter of vegetative bacteria cells is less than 1 pm with a typical length of 1-5 pm. The diameter of fungi (airborne spores) is generally 2-8 pm. General aspects to bear in mind when conducting measurements: Variations in exposure concentrations: Variations in exposure concentrations of m
21、icro-organisms are caused by the fact that the release of micro-organisms into the air from different sources differs over time and space and is therefore not uniform. Calculating the background load: When conducting measurements in closed communal areas, the background load should always be calcula
22、ted using reference measurements in the outside air. The reference measurement shall invariably be taken using the same measurement strategy as in the closed communal area. Determination of exposure peaks: When selecting the measurement method for determining exposure peaks, particular care should b
23、e taken to choose a sampling regime suited to the duration of the exposure peaks. Measurements should be taken before and after the occurrence of exposure peaks to ensure that the maximum concentration of bacteria and fungi in comparison to average exposure levels is recorded. D.3 Measurement princi
24、ple A defined volume of air is drawn through a membrane filter with the aid of a pump integrated in the collection device or connected to the sampling head, and the bacteria/fungi are collected on the filter. Two different methods of analytical determination, both based on cultivation of the bacteri
25、a/fungi, can be used. D.3.1 Cultivation, direct method After use, the filters are laid directly onto the culture medium, incubated and a count is performed. D.3.2 Cultivation, indirect method The bacteria/fungi collected on the filters are first placed in solution and then subjected to serial diluti
26、on before being applied to the culture medium. They are then incubated and a count is performed. The cultivation methods essentially consist in growing the live, reproducible bacteria/fungi on suitable culture media, which permit the growth of as many different species as possible. The determination
27、 limit of the measuring method depends on the analytical method selected (direct, indirect method) and the sampling procedure chosen (flow volume, filter diameter). Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
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