Metody badania środków dezynfekcyjnych

Standardized tests for disinfectants have existed worldwide for over 20 years.  However, not all tests are the same. 

In order to normalize the test methods and the evaluations of the examination authorities, the European Committee for Normalization (CEN) created a technical committee for disinfectants, the CT216. These tests are preferred to all regional test methods. However, in this transitional period the “regional” tests that have existed for a long time (AFNOR, DGHM) are also acceptable. The AFNOR and DGHM standards may be found next to each other in the same dossier.

The test consists of three levels (see the rubric Forms and Explanations). Every test phase and level provides differentiated results, which allows the test to determine the strengths and weaknesses of a product.

• Phase 1 consists of a qualitative suspension test. This phase determines if the product possesses any effectiveness against target organisms. The disinfectant is diluted with water at various concentrations. These tests are qualitative, because the results show whether or not a product is effectiveness at the tested concentration. This phase is not mandatory for the dossier.

• Phase 2 / Level 1 consists of a quantitative suspension test (see rubric Forms and Explanations). The product is not only diluted with water, but also with a solution of impurities that simulates an organic contamination. Such a contamination often occurs in a dental practice, as the surfaces, instruments, or hands that require disinfection are often dirty. This phase is important, as certain substances react strongly with proteins, which causes the product to lose its effectiveness. This test is quantitative, because it calculates the number of eliminated target organisms, expressed as a log10 reduction factor.

• Phase 2 / Level 2 is a decisive test level, as the test conditions are comparable with the real-life circumstances of using a product in a practice (see rubric Forms and Explanations). In other words, this test phase simulates real-life conditions. As opposed to the previous tests, which are the same for all types of application, the tests of this last phase vary according to the proposed application area of the disinfectant. In Phase 2 / Level 2, the following tests are to be undertaken depending on the disinfectant's purpose. 

Instrument disinfection	Germ carrier method. The bacteria are placed on a microscope slide, which is then disinfected in a solution of the test product.
Hand disinfection	Hygienic treatment of the hands through rubbing. Three levels/types of effectiveness are recognized: hygienic hand disinfection (EN1500) hygienic hand washing (EN1499) surgical hand disinfection (EN12791)
Surface disinfection	Treatment of the surface, drying, application of the disinfectant, which can dry during application.

These three phases provide exact information regarding the effectiveness of a disinfectant against various pathogenic target organisms, the necessary concentrations, and the required contact times to reach a satisfactory effectiveness. As these tests are standardized, it is possible to have a reliable comparison of the compositions of the various active substances. For a product to be classified as effective, it must be able to considerably reduce the number of microorganisms, by more than:
      5 log10 for bacteria
      4 log10 for fungi
      4 log10 for viruses

The following proof of effectiveness should be attached to the disinfectant's form. 

Application area	Organism	Quantitative suspension test (Phase 2 / Level 1)	Practical test (Phase 2 / Level 2)
Surface disinfection	Bacteria	EN 1276 or DGHM quantitative suspension test or AFNOR NF T72-300/301	EN 13697 or DGHM surface disinfection or AFNOR NF T72-190
		Fungi	EN 1650 or DGHM quantitative suspension test	DGHM surface disinfection
		Viruses*	EN 14476 or DVV or DVG
	Instrument disinfection	Bacteria	EN 1276 or EN 13727 or EN 14348 or DGHM quantitative suspension test or AFNOR NF T72-300/301	prEN 14561 or prEN 14563 or DGHM quantitative germ carrier test or AFNOR NF T72-190
		Fungi	EN 1650 or EN13624 or DGHM quantitative suspension test	prEN 14562 or DGHM quantitative germ carrier test
		Viruses*	prEN 14476 or DVV or DVG
	Hygienic hand disinfection   (hygienic hand washing)	Bacteria	EN 1276 or DGHM quantitative suspension test or AFNOR NF T72-300/301
		Fungi	EN 1650 or DGHM quantitative suspension test
		Viruses*	EN 14476 or DVV or DVG
	Surgical hand disinfection	Bacteria	EN 1276 or DGHM quantitative suspension test AFNOR NF T72-300/301	EN 12791 or DGHM surgical hand disinfection
		Fungi	DGHM quantitative suspension test EN 1650
		Viruses*	EN 14476 or DVV or DVG

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