EN 16616: 2015. Chemical-thermal textile disinfection. Test method and requirements (phase 2, step 2).
Test accredited by ENAC (Spanish National Accreditation Entity).
This standard describes a test on carrier to establish whether a disinfecting product or a combination of products for the treatment of contaminated textile fabric intended to act in a single wash shows the required microbicidal activity. The standard is intended to validate only the disinfection part of the laundry process. This laboratory test takes into account the practical conditions of application of the product, including contact time, temperature, test microorganisms and interfering substances, i.e. conditions that may influence its action in practice. Each effective dose of the chemical disinfectant found by this test corresponds only to the experimental conditions chosen. When the actual conditions differ from those specified by the standard, additional tests should be carried out to determine the effective dose. Instructions for use are the responsibility of manufacturers of the detergents or disinfectants.
In the test a washing machine with specific characteristics specified by the standard is used, which allows to specify all the washing characteristics. The supplier's instructions should be enough to allow the method described in the standard to be carried out completely (for example, dosing the disinfectant at any stage of the wash, such as rinsing or disinfection at 40°C).
This standard applies to the areas and situations for which disinfection is indicated. Such indications occur during patient care, for example: a) in hospitals, community medical facilities and dental institutions; b) in schools, kinder gardens, and nursing homes; c) institutions in which patients are housed, who may suffer from communicable diseases; d) other applications where hygienic treatment of textile fabric, e.g., food processing, hotels or work clothes such as pharmaceutical industry workers, laboratories, food areas and similar institutions is required.
This is a phase 2, step 2 assay, so the product under test must have passed the phase 2, stage 1 tests, in addition to this test, following EN 13727, EN 13624 and EN 14348 under the conditions of test: 1) the temperature recommended by the manufacturer; 2) the contact time recommended by the manufacturer; 3) dirty conditions and 4) the recommended reduction for instrument disinfection. For products used at >60°C, Standards EN 13624 and EN 14348 should be previously complied with, using Aspergillus brasiliensis and Mycobacterium avium, respectively.
For processes with a temperature <60°C, the process of thermochemical disinfection of a textile fabric is considered effective when in three test series (within a given time, at a recommended dosage, and at a recommended temperature and liquid index), a log reduction of 7 for bacteria; of 6 for Candida albicans and Aspergillus brasiliensis, and a logarithmic reduction of 7 for mycobacteria (Mycobacterium avium and/or Mycobacterium terrae) is obtained. In addition, no microorganism should be detected in 100 ml of the wash / disinfectant liquid. As a minimum requirement, bactericidal and levuricidal activity should be assessed using the following test microorganisms: for the bactericidal activity Pseudomonas aeruginosa, Escherichia coli (K12), Staphylococcus aureus and Enterococcus hirae and for the levuricidal activity Candida albicans. If additional fungicidal activity is claimed, Aspergillus brasiliensis should also be used as a test microorganism. If further tuberculocidal activity is claimed, Mycobacterium terrae should be used as the test microorganism. If a mycobactericidal effect is needed, it is necessary to test with Mycobacterium terrae and Mycobacterium avium.
For processes with temperatures ≥ 60°C, it is considered effective when a logarithmic reduction of Enterococcus faecium superior to 7, is achieved in three test series (within a given time, at a recommended dose, at a process temperature ≥ 60°C and a defined liquid index) on the inside and outside of the carrier. In addition, no microorganism should be detected in 100 ml of the washing / disinfecting liquid. This includes fungicidal, mycobactericidal and tuberculocidal activities. In addition to the mandatory test microorganisms, additional test microorganisms may be selected in accordance with the practical use considered for the product.
The tests use cotton cloth carriers that are contaminated with a test suspension of microorganisms in defibrinated sheep blood. After drying the carriers, they are placed in cotton bags and then subjected to the disinfection process in the washing machine at temperatures of t < 60°C or t ≥ 60°C, as chosen by the manufacturer of the product under test. At the end of the disinfection stage, the bags with the carriers must be removed, in which after the corresponding neutralization of the disinfectant, the microorganisms present will be counted.
The tests use cotton cloth germ carriers that are contaminated with a test suspension of microorganisms in defibrinated sheep blood. After drying the germ carriers, they are placed in cotton bags and then subjected to the disinfection process in the washing machine at temperatures of t <60ºC or t ≥ 60ºC, as chosen by the manufacturer of the product under test. At the end of the disinfection stage, the bags with the germ carriers must be removed, in which, after the corresponding neutralization of the disinfectant, the microorganisms present will be counted.
To order tests with the mycobacteria indicated by the standard or with viruses (viruses are not mandatory according to the EN 16616 standard), it must be previously demonstrated that the product exhibits activity against these microorganisms, at the requested concentration or lower, by means of efficiency tests carried out in accredited laboratories.
Screening tests for textile disinfection products:
The screening test is not carried out in the industrial washing machine, but a laboratory-scale equipment (Gyrowash) is used that simulates the washing process. A cloth support with the test microorganism and the interfering substance will be included in each of the test containers (metal containers of 1 L capacity) with the product solution and the ballast load in the indicated proportion. It should be considered that although the test simulates the washing carried out in the industrial washing machine, the test is not completely equivalent, so this test serves as a guide, but does not guarantee that it complies with the EN 16616 standard.