5.1 This procedure may be used to assess the in vitro reduction of a microbial population of test organisms after exposure to a test material.

1.1 This guide covers an example of a method that measures the changes in a population of aerobic microorganisms within a specified sampling time when antimicrobial test materials are present.

1.1.1 Several options for organism selection and growth, inoculum preparation, sampling times and temperatures are provided.

1.1.2 When the technique is performed as a specific test method, it is critical that the above mentioned variables have been standardized.

1.1.3 Antimicrobial activity of specific materials, as measured by this technique, can vary significantly depending on variables selected.

1.1.4 Test Method E2783 may be referenced as an example of using fixed conditions and set variables to evaluate antimicrobial efficacy of water-miscible compounds.

1.1.5 This guide serves as a general teaching document for evaluating the antimicrobial activity using a variety of conditions to offer the flexibility needed in test conditions to cover a broad range of microorganisms and test substances.

1.1.6 It is important to understand the limitations of in vitro tests, especially comparisons of results from tests performed with different parameters. As an example, test results of microorganisms requiring growth supplements or special incubation conditions may not be directly comparable to organisms evaluated without those stated conditions.

1.2 Knowledge of microbiological techniques is required for this procedure.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.