ASTM E 3286 : 2021

1.1This practice provides a protocol for creating bacterial cell monolayers on a flat surface.

1.2The cultures used and culture preparation steps in this Practice are similar to AOAC Method 961.02 and US EPA MB-06. However, test bacteria are applied to the carrier using an automated deposition device (6.2) rather than as a suspension droplet.

1.3The carrier inspection protocol is similar to US EPA MB-03 except that carrier surfaces are inspected microscopically rather than visually, unaided.

1.4A monolayer of cells eliminates the confounding effect caused by the shadowing effect of outer layers of bacteria stacked upon other bacteria on test specimens – thereby attenuating directed energy beams (that is, ultraviolet light, high-energy electron beams) before they can reach underlying cells.

1.5An asperity-free surface eliminates the shadowing effect of specimen surface topology that can block direct exposure of target bacteria to non-chemical antimicrobial treatments.

1.6This practice provides a reproducible target microbe and surface specimen to minimize specimen variability within and between testing facilities. This facilitates direct data comparisons among various non-chemical antimicrobial technologies.

1.7This practice was validated using Staphylococcus aureus (ATCC 6538) and Pseudomonas aeruginosa (ATCC 15442) using a protocol based on AOAC Method 961.02. If other cultures are used, the suitability of this practice must be confirmed by inspecting prepared surfaces, by using scanning electron microscopy (SEM) or comparable high-resolution microscopy.

1.8The specimens prepared in accordance with this practice are not meant to simulate end-use conditions.

1.9Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.10This 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.

1.11This 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.