Tests of hand disinfection preparations
Admission of a biocidal preparation to the European Union market is possible only after prior registration with the Office for Registration of Medicinal Products, Medical Devices and Biocidal Products. One of the requirements for allowing the preparation to be sold is confirmation of the effectiveness of the product declared by the manufacturer. The analysis of the effectiveness of disinfection products is carried out according to ISO standardized methodologies. Regulation of the testing methodology allows for an objective assessment of the effectiveness of a biocidal preparation.
Types of products intended for hand disinfection
The current epidemiological situation results in a significant increase in the amount of hand disinfectants on the market. Among the ISO standards, there are three basic methodologies for analyzing the biocidal effectiveness of this type of preparations. They allow determining the effectiveness of surgical disinfection (PN-EN 12791+A1:2017-12), hygienic disinfection (PN-EN 1500:2013 07E), and hygienic hand washing (PN-EN 1499:2013 07E).
It is worth noting that a manufacturer wishing to produce products with the effects described above is not obliged to produce three separate preparations. A product with appropriately selected active ingredients may demonstrate biocidal effectiveness within all the above-mentioned standards.
A common feature of the analysis of the biocidal effectiveness of hand disinfectants is testing on probands. Methodologies differ in the number of volunteers necessary to perform the study. Another difference is the amount of product to be analyzed and the criteria for accepting a biocidal product as effective.
Surgical hand disinfection according to the PN-EN 12791+A1:2017-12 standard
The study is performed with 23-28 probands. The effect of the preparation is assessed against the natural microflora of the hands of volunteers participating in the study, which is why the test is preceded by taking fingerprints from their hands. Then, an appropriate amount of the reference agent, which is an isopropanol solution, is applied to the hands of the probands. The impression is made three minutes and three hours after hand contact with the product. After the designated time allowing for the reconstruction of the hand microflora, you can undergo part of the test using the analyzed biocide. First, however, a swab is taken from the probands’ hands again, without contact with any disinfectant. Then, the hand microflora is exposed to the tested preparation, and after 3 minutes and 3 hours, a handprint is made in an appropriate medium. Interpretation of the results involves static analysis by performing the Wilcoxon Test. The biocidal effectiveness of the tested preparation is compared to the antimicrobial activity of the reference product for each proband. The method allows you to confirm the long-term biocidal effectiveness of the product.
Hygienic hand disinfection by rubbing according to the PN-EN 1500:2013 07E standard
The test is performed on 18 to 22 probands, whose hands are contaminated with an appropriately prepared suspension of the reference strain of Escherichia coli. The test begins by taking a print from the palm of the subjects after contact with the bacterial suspension. The microorganisms present on the hands are then exposed to the reference product and the handprint is made again. The last stage of the study begins with contamination of the hands of the test subjects in a manner analogous to the previous one. Then the microorganisms are exposed to the test product and an impression is made again. Similarly to the method performed above, the calculation of results involves static analysis by performing the Wilcoxon Test for pairs of observations. The effectiveness of the tested product is compared to the effectiveness of the reference product. The product, the effectiveness of which is confirmed in the study, can be used to disinfect hands in shopping malls, grocery stores, as well as in schools, kindergartens and hospitals.
Hygienic hand washing according to the PN-EN 1499:2013 07E standard
The method is analogous to that described above. The study involves 12 to 15 probands. The examination begins with contamination of their hands with a suspension of the E. coli strain and taking prints from them. The hands of the probands are re-infected and then exposed to a reference soap washed with water. The last stage of the method is another contamination of the hands, the use of the tested washing preparation and taking a print from the fingertips of the proband. To calculate the results, a comparison of the reduction in the number of microorganisms remaining on the hands after contact with the reference product and with the test product is used for each study participant. Testing the effectiveness of cleaning preparations intended for hygienic hand washing is especially recommended for products used in hospitals, dental offices, nurseries and kindergartens.
