Disinfecting and sanitizing clean areas: Part 1
Regular and well-planned disinfection is crucial for a rapid response to microbiological incidents. Here Patrycja Sitek from CRK discusses how to achieve the most economical result, safe for clean processes and areas
Specialty cleaning cloths are used in many sectors of industry to keep surfaces clean by mechanical removal of dust and biological contamination. Modern materials and the production method allow the amount of disinfectants used to be reduced, while achieving the same bioparticle removal effects. In clean rooms, special cleaning cloths are used to effectively remove bacteria, fungi and viruses from the surface.
Dust and biological pollutants, identified in ISO8-ISO7 cleanroom classes, pose a serious risk of failure in the manufacturing process or experimental research. Environmental monitoring performed to confirm the microbiological and dust cleanliness of air and surfaces serves for the early detection of potential threats as well as the development of effective methods for the removal of pollutants by mechanical surface removal and disinfection.
Among the biological factors that can actually affect the experimental or production process, we can distinguish the so-called TAMC (Total Aerobic Microbial Count) and TYMC (Total Yeasts / Molds Count) – that is, bacteria and aerobic fungi, which are determined on the basis of tests confirming their presence on surfaces or in the product after an incubation time of between 48 and 72 hours. Additionally, in the case of some ISO8-ISO7 laboratories classified in accordance with BSL 3-4 requirements, an important consideration in the selection of specialist cleaning cloths is the risk of surface contamination from hazardous biological agents, including viruses.
In the context of dust pollution, an important element of monitoring is the prevention of contamination of the product and the environment by particles of 0.5 to 5.0 microns. Devices called particle counters are used to monitor the degree of air pollution by particles. Particles that fall to the surface can also transmit microbial contamination, so effective removal of these particles greatly reduces the risk of cross-contamination. In areas where production activities are carried out, activities in the field of risk analysis and validation of the depollution process are carried out in order to confirm the effectiveness of the activities. Validation activities also include qualification processes for cleaning and disinfecting agents as well as cleaning cloths and mop covers. Parameters such as:
- structure and material composition of cleaning cloth
- the degree of release of particles from the surface
- percentage of pollutants eliminated
- the effect of the cleaning cloth used on the reduction of bio-pollutants
- certificates confirming the possibility of using it in a clean room
- the possibility of sterilization of waste
The disinfection process is designed to eliminate microorganisms and their spores. Disinfection destroys the vegetative forms of bacteria and fungi and shows some effectiveness against viruses. Optimization of the selection of appropriate cleaning cloths for ISO8 classes is also associated with the selection of appropriate absorbent cloths, characterized by the appropriate structure and type of fibers, while not generating a risk of contamination of the environment. of production.
Good Manufacturing Practices or Good Laboratory Practices guides not only address disinfection and removal of microorganisms from the surface, but also indicate the need to maintain appropriate microbiological limits, regular monitoring of environment and rotation of agents used for disinfection. At the same time, the Health Council of the Netherlands published in December 2016 a report entitled “Resistance due to disinfectants”, which indicates that the incompetent, too frequent and abundant use of disinfectants is a direct cause of the mutation from environmental strains of microorganisms, including viruses, and becomes resistant to disinfectants, including strong oxidizing agents such as chlorites. APPENDIX 1 EU-GMP requires effective disposal of disinfectant residues as well as debris. It also states that chemical contamination during the disinfection process should be minimized.
Subjecting the provisions of the report to further analysis, the following conclusions should be drawn:
- Too frequent use of disinfectants, especially in so-called critical areas, generates a high concentration of the agent on a given surface per unit of time.
- It is not necessary to constantly use wipes with a disinfectant liquid, called “Ready to use”.
- To maintain the right level of microbiological purity, all that is needed is good disinfection of surfaces and devices, while reducing the frequency of use of the disinfectant.
- Finally – washing the surface with a suitable quality cloth soaked in purified water or, in justified cases, sterile, gives similar effects to the use of a disinfectant and has a real impact on the quantity of disinfectants used.
Modern specialty cleaning cloths are designed and manufactured in such a way as to allow the effective removal of bioburden from the surface with minimal or no use of a disinfectant.
The mechanism of effectiveness of such an action is strictly linked to the mechanical elimination of the microbiological film, and more precisely to the elimination of the bacterial, fungal and viral biomass. The aquatic environment is only one element perfecting this process. The way the fabric is made is of paramount importance in this case. Specialized materials for wiping wet and dry surfaces are characterized by a structure that provides the finest split microfibers, the diameter of which is divided into several dozen segments, thus ensuring excellent efficiency of more than 99.9% for removing bacteria from the surface and 99.51% efficiency in removing viruses, including viruses belonging to the same family and generic group as SARS-CoV-2. The test method used to verify the effectiveness of cleaning cloths of the highest class is based on the EN 16615: 2015 standard. It is based on a quantitative evaluation used to assess bactericidal and yeasticidal activity on surfaces not porous with mechanical action with the use of cloths in the medical field (so-called four-field test). These wipes have different contents of polyester, polyamide and viscose in their structure, in order to ensure maximum absorption and collection capacity of microbial contamination with a minimum level of residual particles.
The technology of cleaning cloths for their safe use of wet and dry services with the achievement of comparable results with the use of disinfectants.
Regular and well-planned disinfection is crucial for a rapid response to microbiological incidents. At the same time, well-designed SOPs for mechanical cleaning and high-quality cloths will respond in an optimal, economical and safe result for clean processes and areas.