Valencian Institute of Microbiology
(I V A M I)

EN 17272: 2020 and BPR: 2023. Methods of airborne room disinfection by automated process - Determination of bactericidal, mycobactericidal, sporicidal, fungicidal, yeasticidal, virucidal and phagocidal activities.

Test accredited by ENAC (Spanish National Accreditation Entity), for standard mandatory and additionals microorganisms or viruses, including under specific conditions of BPR guidance.

The EN 17272: 2020 standard describes a test method to evaluate the biocidal activity (bactericidal, mycobactericidal, sporicidal, fungicidal, levuricidal, virucidal and phagocidal) of air surface disinfection processes. This test is aimed at evaluating the processes that involve air dispersal of a chemical disinfectant in the form of gas, steam and/or aerosol. It is used to evaluate the effectiveness of the process, the product and the devices necessary to carry out the disinfection tests by air. For chemical processes, the product-device combination cannot be separated. The test evaluates the reduction of the test microorganisms located in non-porous supports according to the number of organisms that survive a given air disinfection process. The test method consists of two parts: an efficacy test, designed to ensure that the minimum microorganism reduction requirements are met for each claimed activity; and a distribution test, designed to evaluate the distribution efficiency of the process throughout the test chamber. The standard allows two activity claims depending on the test chamber volumen, depending on the intended use of the process, for the small rooms (less than 4 m³) and large (in test rooms between 30 to 150 m³). The test room in IVAMI has a volumen of 74 m³.

For the efficacy test, each of the biocidal activities can be tested individually, but in order to comply with EN 17272 standard, it must show at least bactericidal and yeasticidal activity. The contact time for disinfection by air, that is, the period from the first release of the disinfectant product to the recovery of the supports or the start of aeration (if an aeration period is considered necessary), must be established according to the manufacturer´s recommendations and must be equal to or less than 15 hours. However, the standard admits as additional mandatory conditions tests with a contact time ≤ 48 hours, if indicated by the manufacturer's instructions and depending on the drying sensitivity of the strains used. Due to the working time frame of our Center, the assays can be selected with times of assay ≤ 8 horas or ≥ 15 horas.  The mandatory temperature at the start of the test is 20ºC ± 2ºC. However, other temperatures may be used as additional requirements if the use of the product, according to the manufacturer´s recommendations, excludes this temperature. The relative humidity at the start of the test should be 50-75%, and it can only be substituted by another humidity range when the use of the product, according to the manufacturer´s instructions, excludes these humidity conditions.

The soiling conditions to be used in the test depend on the sector of use for which the test product is intended. In the event of testing products aimed at the medical sector, the standard establishes clean conditions as mandatory conditions (0.3 g/L BSA and 0.3 g/L BSA + 1/20 milk for microorganisms sensitive to drying), while which includes dirty conditions as additional conditions (in the presence of 3 g/L of BSA plus 3 mg/L of erythrocytes). In the case of testing products for the veterinary sector, the EN 17272 standard establishes low-dirty conditions as mandatory (using 3 g/L of BSA or 3 g/L of BSA + 1/20 of milk for microorganisms sensitive to desiccation) and as additional conditionals those with a high level of dirty (in the presence of 10 g/L of BSA plus 10 g/L of yeast extract or 10 g/L of BSA plus 10 g/L of yeast extract + 1/20 of milk for microorganisms sensitive to desiccation). In case of testing products for the agri-food, industrial, domestic and community sectors, the standard establishes as mandatory conditions the use of clean conditions (0.3 g/L BSA or 0.3 g/L BSA + 1/20 milk for microorganisms sensitive to desiccation), and as additional conditions dirty conditions (in the presence of 3 g/L of BSA or 3 g/L of BSA + 1/20 of milk for sensitive microorganisms).

Note*: The standard admits several adaptations of the test (addition of milk to the interfering substance, increase of the initial inoculum or both) when, under the test conditions indicated by the client, the necessary titer for the test cannot be achieved in controls with microorganisms sensitive to desiccation. If we must repeat the test to adapt the test conditions with some microorganism sensitive to desiccation, such as P. aeruginosa, E. coli or P. hauseri, so that it meets the requirements of the standard, the cost of the test will include a supplement (see cost section).

The efficacy test will be carried out with the following microorganisms or viruses, depending on the activity to be claimed and the sector to which the disinfection process is intended.

To consider the bactericidal product, a log reduction of not less than 5 in the number of viable cells must be demonstrated. For fungicidal, yeasticidal, virucidal, phagocidal, tuberculicidal, and mycobactericidal activities, a reduction of at least 4 logarithms in the number of viable must be demonstrated. To demonstrate efficacy against spores, a logarithmic reduction of at least 4 must be demonstrated in the medical area, while the reduction must be at least 3 logarithms for the veterinary, agri-food, domestic industrial and community sectors.

The distribution test must be carried out under the same conditions as the efficacy test and is always carried out with Staphylococcs aureus, regardless of the activity to be declared. For this, 8 supports are distributed in the test chamber in certain positions and orientations. To consider the test satisfactory, a reduction of at least 5 log must be demonstrated on all supports.

Activity of automatic air surface disinfection processes under specific conditions of the BPR guide (EN 17272: 2020- Antiseptic and chemical disinfectants. Methods of disinfection of rooms by air using automated processes. Determination of bactericidal, mycobactericidal, and sporicidal activities, fungicides, yeasticidal, virucidal and phagocides and BPR guide - Guidance on the Biocidal Products Regulation, ECHA).

The disinfection test by air under the specific conditions of the BPR Guide (Guidance on the Biocidal Products Regulation) involves carrying out the efficacy test with microorganisms other than those indicated by the EN 17272 standard for some areas of application or type of product (PT). In addition, it includes some optional and specific use test microorganisms indicated in the table below. The logarithmic reductions in the number of viable cells must be the same as those indicated for the EN 17272 standard.

The test conditions according to EN 17272 under the specific conditions of the BPR Guidance may also vary depending on the intended use of the product. The test temperature for PT2 and PT4 products must be 20ºC. For PT3, the test temperature must be 10ºC (except for certain applications, such as, hatching-eggs disinfection). The contact time of the test must be that declared by the manufacturer in the products instructions but not higher than 48 hours. Regarding dirty conditions, the BPR Guide indicates some additional interfering substances for certain specific uses, which may vary from those specified by the EN 17272 standard.

Client request for the assay

The client must indicate if he wishes to carry out the test according to EN 17272 or following the BPR Guide. Depending on the choice made, the report will indicate that the test is performed following the EN 17272 standard, or following the EN 17272 standard under the specific conditions of the BPR Guide. If the test is carried out according to the EN 17272 standard only, the report will not refer to the PTs, but to the sectors of use (medical sector, veterinary sector, and the agri-food, industrial, domestic and community sectors).

When the test is requested for several sectors or PT, the soiling conditions of each sector must be taken into account. In addition, if it is carried out under the conditions of the BPR guidance, the test temperature must be taken into account, which can vary between PTs. Lastly, the EN 17272 standard indicates that to evaluate sporicidal activity in the medical area (medical sector or Pt2 medical area) the inoculum used must be higher than that used for the rest of the sectors or PT. Therefore, either the tests are requested for each area separately or they must be carried out under the most demanding conditions (the inoculum indicated for the medical sector).

In case of carrying out the test, you must send the appropriate emission devices for the volume of the test room used in the laboratory (74 m³; seventy-four cubic meters). It should be noted that it may be necessary to perform the test have several days of testing. The quantity of product that must be sent depends on the volume consumed in each disinfection process and the cycles that are necessary to declare the required activities. An independent complete disinfection process must be carried out for each group of microorganisms, that is, if bactericidal and yeasticidal activity is required, two complete disinfection processes will be carried out, so the volume necessary to complete these cycles must be sent. Furthermore, if viricidal activity is required, an additional prior disinfection cycle must be performed to evaluate the cytotoxicity of the product. However, it is recommended to send more product than the minimum necessary, in case a cycle needs to be repeated to confirm a result.

For tests with multiple microorganisms or several conditions, you can ask us for the quantity of product to send, indicating all the test conditions to be carried out (microorganisms, interfering substance, time, test temperature and application area).