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In: 45th R3Nordic Symposium. Cleanroom Technology, Contamination Control and Cleaning. Wirtanen, Gun & Salo, Satu. VTT Technology 168, 139 - 141 ; Food safety is related to the absence or presence of levels of foodborne hazards in food at the point of consumption. The EC Regulation 852/2004 covers the principal objective of the general hygiene rules to ensure a high level of consumer protection with regard to food safety. However, food safety is the joint responsibility of many people and it is principally ensured through the combined efforts of all the parties in the food chain. Legislative demands set the basic requirements for the manufacturing of safe food products whereas food safety management systems and food safety guidelines and standards based on given legislation help the food industry to keep up with current food safety requirements. Hygiene survey is a practical tool for controlling hygiene in food plants. By using an efficient sampling of the surfaces of the process line, it is possible to reduce the amount of low-quality food leaving the plant. Hygiene survey can include checking of the amount of surface-attached soil including protein, polysaccharides, other organic and inorganic residues, biofilm, dead and/or living microbes in general, or specific pathogens and other harmful microbes. Hygiene survey also helps with tracing contamination sources and in optimising cleaning systems. There are several sources of microbial contamination: raw materials, process equipment, environmental surfaces, air, personnel and the final product. In some cases demands for better hygiene have been made because of prolonged shelf-life of products, centralized production and long-distance transportation, less time spent on cleaning and demands for environmentally safe cleaning agents (Salo, 2006). Quantification of the actual number of microbes from surfaces is difficult due to strong microbial adherence of biofilms. In addition, detection of biofilms using traditional swabbing method often gives incorrect results due to strong microbial adherence. Most techniques underestimate the number of microbes on a surface. Hygiene surveys from surfaces are challenging; the measuring should be quickly performed, directly from the surface and without damaging the surface, and the microbes need to be detached completely. However, it is difficult to measure biofilm and biotransfer potential because the conventional microbiological methods used to assess equipment hygiene have not been developed for detecting biofilm. Reliable results are only possible if the biofilm is properly detached and the cultivation is performed under reproducible conditions or if the measurement can be performed without detaching the microbes. Microscopy is very often used as a reference method for swabbing and cultivation. It has been reported that the cells counted by direct microscopy consistently give results one log unit higher than the cultivation methods. Moreover, observations of surfaces using epifluorescence microscopy have clearly revealed that even when vigorous swabbing is applied only a small part of the actual biofilm including the cells in it is detached (Wirtanen, 1995). On the other hand, use of excessive agitation and strong chemicals for detachment of surface-adherent cells may harm the cells, thus making them unable to grow in the cultivation procedure. Choosing sampling sites in food plants and especially in equipment with complicated structures is challenging, since most likely the microbial residues are in curvatures, con-nections, propellers, or on uneven surfaces which are not easy to reach with sampling tools. Quantification of the swabbed areas in places like these is challenging. Contact agar applications with ridged frames are only suitable for sampling of smooth and straight surfaces (Salo et al., 2008). Preventive risk-based food safety management systems such as HACCP require that hygiene monitoring should provide results rapidly in order to be able to perform corrective actions. ATP bioluminescence and protein detection kits for instance can provide a real time estimation of overall cleaning efficacy or protein residues, respectively. The detection and enumeration of indicator organisms is widely used to assess the efficacy of sanitation procedures. Escherichia coli counts can be used as an indirect measure of faecal contamination. The use of Enterobacteriaceae as hygiene indicators instead of coliforms or E. coli yields much more precise results. Interpretation of the results from hygiene monitoring is often carried out case by case since there are quite many factors affecting an acceptable level of cleanliness. The ac-ceptable level depends on the purpose of the surface. The surfaces in contact with ready-to-eat food products must be much cleaner than other surfaces in the process plant in contact with products which will be pasteurised or surfaces in no direct contact with foods. Special attention should also be paid to the surfaces next to food contact surfaces since there is a high risk of spreading contamination to food products (Salo et al., 2006). The cleanliness level of the processed product depends also on the spoilage sensitivity and the wanted self-life of the product. The available recommended guidelines and standards for aerobic colony counts for clean surfaces vary widely, being 0 - 80 CFU/cm2 (Griffith, 2005). The threshold limit for clean surface must be based upon a perception of a specific risk and the decided acceptable level. Alternatively, microbial yield obtained from surface after correct imple-mentation of a well-designed cleaning programme can be used as a desired value (Griffith, 2005). Comprehensive studies performed by Griffith (2005) have indicated that in many cases levels of <2.5 CFU/cm2 for general surface count are attainable and these are relatively close to majority of suggested standards. In the microbial survey described in Salo et al., 2006 the threshold limit for clean surface was set based in perception of risk to <2 CFU/cm2. Suitable methods for detecting cleanliness of process surfaces vary according to the situation studied. All available methods have limitations and the suitability of the method strongly depends on the type of microbes and the microbial load present. Traditional sampling with swabs prior to culturing does not detach all microbes attached to the surface. Swabbing can be improved by moistening the surface with mild surfactant solution. Also flexible contact agar is suitable for the detection of microbes from process equipment, and if the microbial load is less than 30 CFU/cm2 the microbial colonies can be counted. It is recommended to use more than one detection method in new environment to validate the results obtained. A clean surface has to be free of microbes, physical particles and chemicals. Chemical residues remaining after cleaning and disinfection can be detected using rapid methods based on bioluminescence of sensitive photobacteria. Visual observation of the cleaning results is an important practical method which can be improved by using UV-light and possibly fluorescent stain. This type of assessment is not very accurate but is a practical choice especially for large equipment such as fermentation tanks. ; Food safety is related to the absence or presence of levels of foodborne hazards in food at the point of consumption. The EC Regulation 852/2004 covers the principal objective of the general hygiene rules to ensure a high level of consumer protection with regard to food safety. However, food safety is the joint responsibility of many people and it is principally ensured through the combined efforts of all the parties in the food chain. Legislative demands set the basic requirements for the manufacturing of safe food products whereas food safety management systems and food safety guidelines and standards based on given legislation help the food industry to keep up with current food safety requirements. Hygiene survey is a practical tool for controlling hygiene in food plants. By using an efficient sampling of the surfaces of the process line, it is possible to reduce the amount of low-quality food leaving the plant. Hygiene survey can include checking of the amount of surface-attached soil including protein, polysaccharides, other organic and inorganic residues, biofilm, dead and/or living microbes in general, or specific pathogens and other harmful microbes. Hygiene survey also helps with tracing contamination sources and in optimising cleaning systems. There are several sources of microbial contamination: raw materials, process equipment, environmental surfaces, air, personnel and the final product. In some cases demands for better hygiene have been made because of prolonged shelf-life of products, centralized production and long-distance transportation, less time spent on cleaning and demands for environmentally safe cleaning agents (Salo, 2006). Quantification of the actual number of microbes from surfaces is difficult due to strong microbial adherence of biofilms. In addition, detection of biofilms using traditional swabbing method often gives incorrect results due to strong microbial adherence. Most techniques underestimate the number of microbes on a surface. Hygiene surveys from surfaces are challenging; the measuring should be quickly performed, directly from the surface and without damaging the surface, and the microbes need to be detached completely. However, it is difficult to measure biofilm and biotransfer potential because the conventional microbiological methods used to assess equipment hygiene have not been developed for detecting biofilm. Reliable results are only possible if the biofilm is properly detached and the cultivation is performed under reproducible conditions or if the measurement can be performed without detaching the microbes. Microscopy is very often used as a reference method for swabbing and cultivation. It has been reported that the cells counted by direct microscopy consistently give results one log unit higher than the cultivation methods. Moreover, observations of surfaces using epifluorescence microscopy have clearly revealed that even when vigorous swabbing is applied only a small part of the actual biofilm including the cells in it is detached (Wirtanen, 1995). On the other hand, use of excessive agitation and strong chemicals for detachment of surface-adherent cells may harm the cells, thus making them unable to grow in the cultivation procedure. Choosing sampling sites in food plants and especially in equipment with complicated structures is challenging, since most likely the microbial residues are in curvatures, con-nections, propellers, or on uneven surfaces which are not easy to reach with sampling tools. Quantification of the swabbed areas in places like these is challenging. Contact agar applications with ridged frames are only suitable for sampling of smooth and straight surfaces (Salo et al., 2008). Preventive risk-based food safety management systems such as HACCP require that hygiene monitoring should provide results rapidly in order to be able to perform corrective actions. ATP bioluminescence and protein detection kits for instance can provide a real time estimation of overall cleaning efficacy or protein residues, respectively. The detection and enumeration of indicator organisms is widely used to assess the efficacy of sanitation procedures. Escherichia coli counts can be used as an indirect measure of faecal contamination. The use of Enterobacteriaceae as hygiene indicators instead of coliforms or E. coli yields much more precise results. Interpretation of the results from hygiene monitoring is often carried out case by case since there are quite many factors affecting an acceptable level of cleanliness. The ac-ceptable level depends on the purpose of the surface. The surfaces in contact with ready-to-eat food products must be much cleaner than other surfaces in the process plant in contact with products which will be pasteurised or surfaces in no direct contact with foods. Special attention should also be paid to the surfaces next to food contact surfaces since there is a high risk of spreading contamination to food products (Salo et al., 2006). The cleanliness level of the processed product depends also on the spoilage sensitivity and the wanted self-life of the product. The available recommended guidelines and standards for aerobic colony counts for clean surfaces vary widely, being 0 - 80 CFU/cm2 (Griffith, 2005). The threshold limit for clean surface must be based upon a perception of a specific risk and the decided acceptable level. Alternatively, microbial yield obtained from surface after correct imple-mentation of a well-designed cleaning programme can be used as a desired value (Griffith, 2005). Comprehensive studies performed by Griffith (2005) have indicated that in many cases levels of <2.5 CFU/cm2 for general surface count are attainable and these are relatively close to majority of suggested standards. In the microbial survey described in Salo et al., 2006 the threshold limit for clean surface was set based in perception of risk to <2 CFU/cm2. Suitable methods for detecting cleanliness of process surfaces vary according to the situation studied. All available methods have limitations and the suitability of the method strongly depends on the type of microbes and the microbial load present. Traditional sampling with swabs prior to culturing does not detach all microbes attached to the surface. Swabbing can be improved by moistening the surface with mild surfactant solution. Also flexible contact agar is suitable for the detection of microbes from process equipment, and if the microbial load is less than 30 CFU/cm2 the microbial colonies can be counted. It is recommended to use more than one detection method in new environment to validate the results obtained. A clean surface has to be free of microbes, physical particles and chemicals. Chemical residues remaining after cleaning and disinfection can be detected using rapid methods based on bioluminescence of sensitive photobacteria. Visual observation of the cleaning results is an important practical method which can be improved by using UV-light and possibly fluorescent stain. This type of assessment is not very accurate but is a practical choice especially for large equipment such as fermentation tanks.

VTT Symposium 260 ; Microbial risk management is difficult and very important in food processing and although we have common EU legislation for food producers microbial risk management needs to be improved and harmonized within EU countries. Microbial risk management consists of several parts. Knowledge of hygienic design and factory layout can prevent severe microbial hazards. Virtual simulations and modelling can help in testing and improving the hygienic design of complex food processing lines. Microbiological sampling from large and closed process equipment is challenging. Choosing suitable cleaning agents and disinfectants for various food processing equipment and process environment requires knowledge about efficacy of chemicals and properties of surface materials. Estimation of severities and probabilities of microbiological risks in food factories is dependent on the experience of the person doing the estimation. Decision support tools such as HYGRAM can be used for making risk assessment in food factories. The workshop on Microbiological risk management in food processes was held in Lyngby (Denmark) 13th-15th of October 2008. The theoretical session focused on preventive activities such as hygienic design, factory layout, applications of mathematical models and predictive microbiology, applying and efficacy testing of cleaning agents and disinfectants, HACCP and risk assessment. The theoretical part prepared participants to three practical exercises; hygienic design based on cleaning flows in pipelines and dismantling of small equipment, testing disinfection efficacy and residues of disinfectants and HACCP-based risk assessment. The participant abstracts are also published in this publication.

41st R3-Nordic Symposium. Cleanroom technology, contamination control and cleaning, Dipoli, Espoo, Finland, May 25 - 26, 2010. Wirtanen, Gun & Salo, Satu. VTT Symposium 266, 199 - 207 ; VTT is the biggest multitechnological applied research organisation in Northern Europe, which creates new technology and science-based innovations in co-operation with domestic and foreign partners. In the food sector, VTT aims to deliver technological solutions for high quality products, which meet consumer needs, mainly by developing health-promoting foods with good sensory properties. VTT's core competencies in food science include knowledge on: a) Processing of cereals, berries and vegetables by enzymes, microbes and dry fractionation, b) Enzymatic engineering of bulk and interfacial biopolymer structures for improved food quality, c) Development of probiotics and the technology related to their use, d) In vitro platform for physiological responses, including a gut model, food metabolomics and the measurement of satiety, e) Understanding of the role of healthiness in food choices, f) Testing of consumer acceptance of new food technologies, products & services, and g) Upgrading the value of side streams, such as milling by-products, brewers spent grains and oil plant residues. Many of these competencies involve a lot of laboratory research and analytical equipment. We are specialized in applied research, so the scale-up possibilities from the small laboratory scale into intermediate pilot scale (ca. 1-10 kg/h) are essential, because we want to serve both academic and industrial fields. For example, industrial companies are able to test new kinds of processes or the manufacture of new products in the pilot scale, without interrupting their production lines and avoiding the wastage of raw materials. We have equipment for a broad range of processing possibilities, mainly focused on modification of ingredients, such as cereals and berries. The modification can be enzymatic, thermomechanical and/or physical. We have pilot scale fermentation vessels, mills, air classifier, extruder, as well as freeze-, fluidised bed- and spray dryers. In addition, we have separate facilities for pilot scale brewing and baking. VTT's facilities for pilot scale food processing were built in 1986. Since then the requirements for better hygiene and process safety have tightened significantly. In Finland, the facilities for commercial food production are governed by the statute of food surveillance (Finnish Government, 321/2006). On the other hand, the facilities for food research are not governed by the same statute, i.e. they are not governmentally monitored as far as the production is not aiming at commercial markets. Despite this exception in the food law, we wanted to ensure that our products are manufactured and monitored by the newest standards of hygiene and safety. ; VTT is the biggest multitechnological applied research organisation in Northern Europe, which creates new technology and science-based innovations in co-operation with domestic and foreign partners. In the food sector, VTT aims to deliver technological solutions for high quality products, which meet consumer needs, mainly by developing health-promoting foods with good sensory properties. VTT's core competencies in food science include knowledge on: a) Processing of cereals, berries and vegetables by enzymes, microbes and dry fractionation, b) Enzymatic engineering of bulk and interfacial biopolymer structures for improved food quality, c) Development of probiotics and the technology related to their use, d) In vitro platform for physiological responses, including a gut model, food metabolomics and the measurement of satiety, e) Understanding of the role of healthiness in food choices, f) Testing of consumer acceptance of new food technologies, products & services, and g) Upgrading the value of side streams, such as milling by-products, brewers spent grains and oil plant residues. Many of these competencies involve a lot of laboratory research and analytical equipment. We are specialized in applied research, so the scale-up possibilities from the small laboratory scale into intermediate pilot scale (ca. 1-10 kg/h) are essential, because we want to serve both academic and industrial fields. For example, industrial companies are able to test new kinds of processes or the manufacture of new products in the pilot scale, without interrupting their production lines and avoiding the wastage of raw materials. We have equipment for a broad range of processing possibilities, mainly focused on modification of ingredients, such as cereals and berries. The modification can be enzymatic, thermomechanical and/or physical. We have pilot scale fermentation vessels, mills, air classifier, extruder, as well as freeze-, fluidised bed- and spray dryers. In addition, we have separate facilities for pilot scale brewing and baking. VTT's facilities for pilot scale food processing were built in 1986. Since then the requirements for better hygiene and process safety have tightened significantly. In Finland, the facilities for commercial food production are governed by the statute of food surveillance (Finnish Government, 321/2006). On the other hand, the facilities for food research are not governed by the same statute, i.e. they are not governmentally monitored as far as the production is not aiming at commercial markets. Despite this exception in the food law, we wanted to ensure that our products are manufactured and monitored by the newest standards of hygiene and safety.

BACKGROUND: The shortage of FFP2 and FFP3 respirators posed a serious threat to the operation of the healthcare system at the onset of the COVID-19 pandemic. AIM: Our aim was to develop and validate a large-scale facility that uses hydrogen peroxide vapour for the decontamination of used respirators. METHODS: A multidisciplinary and multisectoral ad hoc group of experts representing various organisations was assembled to implement the collection and transport of used FFP2 and FFP3 respirators from hospitals covering 86% of the Finnish population. A large-scale decontamination facility using hydrogen peroxide vapour was designed and constructed. Microbiological tests were used to confirm efficacy of hydrogen peroxide vapour decontamination together with a test to assess the effect of decontamination on the filtering efficacy and fit of respirators. Bacterial and fungal growth in stored respirators was determined by standard methods. RESULTS: Large-scale hydrogen peroxide vapour decontamination of a range of FFP2 and FFP3 respirator models effectively reduced the recovery of biological indicators: Geobacillus stearothermophilus and Bacillus atrophaeus spores, as well as model virus bacteriophage MS2. The filtering efficacy and facial fit after hydrogen peroxide vapour decontamination were not affected by the process. Microbial growth in the hydrogen peroxide vapour-treated respirators indicated appropriate microbial cleanliness. CONCLUSIONS: Large-scale hydrogen peroxide vapour decontamination was validated. After effective decontamination, no significant changes in the key properties of the respirators were detected. European Union regulations should incorporate a facilitated pathway to allow reuse of appropriately decontaminated respirators in a severe pandemic when unused respirators are not available.