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Determination of the Efficacy of Sterile Barrier Systems Against Microbial Challenges During Transport and Storage

Published online by Cambridge University Press:  02 January 2015

Hartmut Dunkelberg  and
Ulrich Schmelz
Hartmut Dunkelberg*
Affiliation:
Medical Institute of General Hygiene and Environmental Health, University of Göttingen, Göttingen, Germany
Ulrich Schmelz
Affiliation:
Medical Institute of General Hygiene and Environmental Health, University of Göttingen, Göttingen, Germany
*
Medical Institute of General Hygiene and Environmental Health, University of Göttingen, Lenglerner Str. 75, D-37079 Göttingen, Germany (hdunkell@gwdg.de)
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Abstract

Objective.

The sterility assurance level of 10−6 is an established standard that defines the quality of sterile products. The aim of the present study was to develop a method that correlated the results from microbial-barrier testing of flexible sterile barrier systems with the estimated microbial challenge that the package encounters during storage and transport.

Methods.

The effectiveness of microbial-barrier packaging was determined by the use of an exposure chamber test with 20 periodic atmospheric pressure changes of 50 and 70 hPa. Flexible peel pouches were used as sterile barrier systems. The logarithmic reduction value of a sterile barrier system was calculated on the basis of the experimental results and compared with the logarithmic reduction value required for the microbial challenges to maintain sterility during transport and storage.

Results.

For pouches made of paper and plastic-film material, a logarithmic reduction value of 5.4 was obtained on the basis of 30 of 99 plates becoming nonsterile after being exposed to a 50 hPa difference in periodic atmospheric pressure changes. For pouches made of paper and plastic-film material, a logarithmic reduction value of 5.2 was obtained on the basis of 48 of 100 plates becoming nonsterile after being exposed to a 70 hPa difference in atmospheric pressure. For pouches made of nonwoven and plastic-film material, logarithmic reduction values of 6.38 (ie, 3 of 99 plates became nonsterile after being exposed to a 50 hPa pressure difference) and 6.07 (ie, 3 of the 99 plates became nonsterile after being exposed to a 70 hPa pressure difference) were obtained. Calculating an expected microbial challenge during transport and storage that requires barrier properties corresponding to a logarithmic reduction value of 5.83 and taking the sterility assurance level into account, we found that only the nonwoven pouches fulfilled the European standard EN 556-1.

Conclusions.

Using the data obtained in a microbial exposure test with a specified flow rate of a bacterial aerosol, we found that the effectiveness of the sterile barrier system against the actual microbial challenge can be examined and evaluated at the sterility assurance level of 10−6.

Type
Original Articles
Information
Infection Control & Hospital Epidemiology , Volume 30 , Issue 2 , February 2009 , pp. 179 - 183
Copyright
Copyright © The Society for Healthcare Epidemiology of America 2009

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References

1.International Organization for Standardization (ISO). Packaging for terminally sterilized medical devices—part 1: requirements for materials, sterile barrier systems and packaging systems. Document ISO 11607-1:2006. Available at: http://www.iso.org. Accessed December 5, 2008.Google Scholar
2.European Committee for Standardization. Packaging materials and systems for medical devices which are to be sterilized—part 3: paper for use in the manufacture of paper bags (specified in EN 868-4) and in the manufacture of pouches and reels (specified in EN 868-5)—requirements and test Methods. Document EN 868-3:1999. Available at: http://www.cen.eu/esearch. Accessed December 5, 2008.Google Scholar
3.Klapes, NA, Greene, VW, Langholz, AC, Hustinger, C. Effect of long-term storage on sterile status of devices in surgical packs. Infect Control 1987;8:289–293.Google Scholar
4.Butt, WE, Bradley, DV Jr, Mayhew, RB, Schwartz, RS. Evaluation of the shelf life of sterile instrument packs. Oral Surg Oral Med Oral Pathol 1991;72:650–654.Google Scholar
5.Bhumisirikul, W, Bhumisirikul, P, Pongchairerks, P. Long-term storage of small surgical instruments in autockved packages. Asian J Surg 2003;26:202–204.CrossRefGoogle ScholarPubMed
6.Widmer, AF, Houston, A, Bollinger, E, Wenzel, RP. A new standard for sterility testing for autoclaved surgical trays. J Hosp Infect 1992;21:253–260.Google Scholar
7.Allison, DG. A review: taking the sterile out of sterility. J Appi Microbiol 1999;87:789–793.CrossRefGoogle ScholarPubMed
8.European Committee for Standardization. Sterilization of medical devices—requirements for medical devices to be designated “STERILE”— part 1: requirements for terminally sterilized medical devices. Document EN 556-1:2001. Available at: http://www.cen.eu/esearch. Accessed December 5, 2008.Google Scholar
9.US Food and Drug Administration. Guidance for industry: container and closure system integrity testing in lieu of sterility testing as a component of the stability protocol for sterile products. February 22, 2008. Available at: http://www.fda.gov/cber/gdlns/contain.htm. Accessed June 30, 2008.Google Scholar
10.Dunkelberg, H, Rohmann, S. Test to determine sterile integrity of wrapped medical products at a probability of recontamination of 1 : 1,000,000. Infect Control Hosp Epidemiol 2006;27:367–371.Google Scholar
11.Dunkelberg, H, Fleitmann-Glende, F. Measurement of the microbial barrier effectiveness of sterilization containers in terms of the log reduction value for prevention of nosocomial infections. Am J Infect Control 2006;34:285–289.CrossRefGoogle ScholarPubMed
12.Augustowska, M, Dutkiewicz, J. Variability of airborne microflora in a hospital ward within a period of one year. Ann Agric Environ Med 2006;13:99–106.Google Scholar
13.Bouillard, L, Michel, O, Dramaix, M, Devleeschouwer, M. Bacterial contamination of indoor air, surfaces, and settled dust, and related dust endotoxin concentrations in healthy office buildings. Ann Agric Environ Med 2005;12:187–192.Google Scholar
14.Webster, J, Lloyd, W, Ho, P, Burridge, Ch, George, N. Rethinking sterilization practices: evidence for event-related outdating. Infect Control Hosp Epidemiol 2003;24:622–624.Google Scholar
15.VA Technology Assessment Program. Office of Patient Care Services. Shelf-life of stored sterilized materials: final report. Brief overview. Shelf-life of stored sterilized materials: should VHA adopt expiration dating or event-related outdating? March 2004. Available at: http://www.va.gov/vatap. Accessed June 2008.Google Scholar
16.Dunkelberg, H, Wedekind, S. Preliminary results for a new final package test to assess the quality of sterile package systems. Infect Control Hosp Epidemiol 2004;25:26–29.Google Scholar