Antimicrobial Test Methods in the European Union

Lionel Pineau

In Europe, any biocidal product falling under the scope of European Medical Devices Directive (MDD) 93/42/EEC¹ and, in the future, the regulation (EU) 2017/745² or under the scope of European Biocides Regulation 528/2012³ shall be tested according to the test methods developed by Technical Committee 216 of the European Committee for Standardization and listed in the European standard EN 14885.⁴ These tests are used to support claims appropriate to their intended application. Other test methods can be used when the models specified in the standards are not sufficient and/or appropriate to demonstrate the product claim (eg, activity against biofilm).

In Europe, three different areas of application are defined for antiseptics and disinfectants:

Medicine (hospitals, medical facilities and dental institutions, laundries and kitchens supplying products directly for the patient)
Veterinary area
Food, industrial, domestic, and institutional areas (processing, distribution, and retailing of food of animal or vegetable origin)

For each area, EN 14885 specifies European standards to which products should conform to support their claims for microbicidal activity (Tables 63.1, 63.2 and 63.3). This standard is also intended to enable users of the product to understand the antimicrobial efficacy information provided by the manufacturer and assist competent bodies in assessing claims made by the manufacturer. Even if this approach could be considered comparable to what is done in other countries or regions to register a chemical disinfectant, the definitions, methods used, and performance requirements are different. The most important differences concern the nature and definition of the products intended to be tested. In some countries like in United States³³ or in Australia,³⁴ some chemicals can be used to sterilize critical medical devices (eg, products labeled as sterilants), whereas in Europe, the terms sterility, sterile, sterilization, or sterilant are not defined in this series of European disinfectant testing standards and a disinfectant cannot be regarded as a sterilant; sterilization requirements are defined in other European (EN) and/or International Organization for Standardization (ISO) standards (chapter 70).

TEST CATEGORIES

In the EN chemical disinfection standards, four categories of tests are described:

Phase 1 tests: quantitative suspension tests to demonstrate that an active substance or a product under development presents bactericidal, fungicidal, or sporicidal activity in fixed conditions (obligatory test conditions) without considering the use conditions specified by the manufacturer. In that case, the contact time and the temperature to be tested are fixed (see Table 63.4).
Phase 2, step 1 tests: quantitative suspension tests to establish that a product has bactericidal, fungicidal, sporicidal, or virucidal activity simulating practical conditions. Tests shall be performed first in obligatory tests conditions, and some additional test conditions are permitted.
Phase 2, step 2 tests: quantitative tests equivalent to phase 2 step 1 tests but performed against microorganisms dried on test surfaces (with obligatory and additional test conditions)
Phase 3 tests: field tests under practical use conditions. Validated methodology for this type of test is not yet available.

Phase 1 and 2 tests are conducted to establish the broad spectrum of microbial activity of the disinfectant. They can be comparable to potency tests because they are described in the United States requirements such as the U.S. Food and Drug Administration (FDA) 510(k)

guidance document for liquid chemical sterilants and high-level disinfectant.³³ Phase 3 tests are field trials performed to establish the performance of a product under actual use conditions. They correspond to simulated use tests or in use tests described in US and Australian regulations.³³,³⁴

TABLE 63.1 Medical area—standard test methods to be used to substantiate claims for products (as of May, 2019)

Activity Claims	Phase/Step	Type and/or Purpose of Product
		Hygienic Hand Rub	Hygienic Hand Wash	Surgical Hand Rub and Surgical Hand Wash	Surface Disinfection		Instrument Disinfection	Textile Disinfection	Water Disinfectant
					Mechanical Action
					Without	With
Bactericidal	2.1	EN 13727⁵			EN 13727⁵		EN 13727⁵	*	**
Bactericidal	2.2	EN 1500⁶	EN 1499⁷	EN 12791⁸	EN 13697⁹	EN 16615¹⁰	EN 14561¹¹	EN 16616¹²	**
Yeasticidal	2.1	EN 13624¹³			EN 13624¹³		EN 13624¹³	***	**
Yeasticidal	2.2	**			EN 13697⁹	EN 16615¹⁰	EN 14562¹⁴	EN 16616¹²	**
Fungicidal	2.1	**			EN 13624¹³		EN 13624¹³	*	**
Fungicidal	2.2	**			EN 13697⁹	*	EN 14562¹⁴	EN 16616¹²	**
Tuberculocidal	2.1	EN 14348¹⁵	EN 14348¹⁵	**	EN 14348¹⁵		EN 14348¹⁵	EN 14348¹⁵	**
Tuberculocidal	2.2	**			*	*	EN 14563¹⁶	EN 16616¹²	**
Mycobactericidal	2.1	EN 14348¹⁵	EN 14348¹⁵	**	EN 14348¹⁵		EN 14348¹⁵	EN 14348¹⁵	**
Mycobactericidal	2.2	**			*	*	EN 14563¹⁶	EN 16616¹²	**
Virucidal	2.1	EN 14476¹⁷	EN 14476¹⁷	**	EN 14476¹⁷		EN 14476¹⁷	EN 14476¹⁷	**
Virucidal	2.2	*	*	**	***		*	***	**
Sporicidal	2.1	**			***		***	*	**
Sporicidal	2.2	**			***	*	*	**	**
Legionella	2.1	**			**		**	**	EN 13623¹⁸
Abbreviations: , no work items are yet approved, but relevant standards may become available in the future; , no intention to develop a test; **, work item approved.

TABLE 63.2 Veterinary area—standard test methods to be used to substantiate claims for products (as of May 2019)

Activity Claims	Phase/Step	Type and/or Purpose of Product
		Surface Disinfection		Teat Disinfection	Immersion of Contaminated Objects High-Level Soiling	Hygienic Hand Rub Hygienic Hand Wash Surgical Hand Rub and Surgical Hand Wash
		Mechanical Action
		Without	With
Bactericidal	2.1	EN 1656¹⁹	*	EN 1656¹⁹	EN 1656¹⁹	EN 13727⁵
	2.2^a	EN 14349²⁰	*	**	EN 14349²⁰	EN 1499⁷ or EN 1500⁶ or EN 12791⁸
	2.2^b	EN 16437²¹	NA	**	**	**
Yeasticidal	2.1	EN 1657²²	*	**	EN 1657²²	**
	2.2^a	EN 16438²³	NA	**	EN 16438²³	**
	2.2^b	*	*	**	**	**
Fungicidal	2.1	EN 1657²²	*	**	EN 1657²²	EN 13624¹³
	2.2^a	EN 16438²³	NA	**	EN 16438²³	**
	2.2^b	*	*	**	**	**
Mycobactericidal	2.1	EN 14204²⁴	*	**	EN 14204²⁴	**
	2.2^a	*	*	**	*	**
	2.2^b	*	NA	**	**	**
Virucidal	2.1	EN 14675²⁵	*	**	EN 14675²⁵	EN 14476¹⁷
	2.2^a	*	*	**	*	**
	2.2^b	*	NA	**	**	**
Sporicidal	2.1	*	*	**	*	**
	2.2^a	*	*	**	*	**
	2.2^b	*	*	**	**	**
Abbreviations: , no work items are yet approved, but relevant standards may become available in the future; *, no intention to develop a test; NA, not available. ^aNonporous surfaces. ^bPorous surfaces.