ASTM E3363-23 PDF

SIGNIFICANCE AND USE 5.1 The plastic Petri plate (carrier) provides a closed system for enumeration and easy application of a pre-saturated or impregnated antimicrobial towelette by an analyst. 5.2 Aliquoting of sterile 5 % non-heat-inactivated fetal bovine serum (five 10 µL spots) onto soiled carriers and inoculation of final test suspension onto treated carriers (five 10 µL spots) is conducted using a template and a positive displacement pipette, thereby ensuring a precise inoculum level and uniform distribution of soil and final test suspension. 5.3 A single towelette is tested per 2-carrier set, eliminating the likelihood of cross contamination between carriers. 5.4 The corkscrew-patterned circular motion of the product application (wipe outside to inside, wipe inside to outside using the wiping template; see Annex A3 – Annex A6) ensures uniform coverage and contact of disinfectant with the inoculated surface. 5.5 The addition of neutralizer to the treated carriers at the end of the contact time results in neutralization of the test substance. This standard test method provides a procedure for performing neutralization verification to confirm that the microbicidal, microbistatic, or both types of activity of a test substance has been reduced by 50 % at the end of the contact time (see Annex A1 for neutralization verification procedure). 5.6 The design of this standard test method minimizes any loss of viable organisms through carrier wash-off. 5.7 It is optional to adjust (dilution in PBS) the inoculum to achieve desired control counts of 5.0 log10 CFU/carrier to 6.5 log10 CFU/carrier. 5.8 Include, where applicable, comparisons of the test to other similar procedures such as Practices E1054 and E2362. SCOPE 1.1 This test method quantitatively determines the effectiveness of various sizes of antimicrobial towelettes in treating hard, non-porous surfaces against Pseudomonas aeruginosa and Staphylococcus aureus. 1.2 This test method may be used to evaluate towelettes for antimicrobial efficacy against additional microorganisms (with necessary modifications). 1.2.1 This test method does not differentiate between chemical inactivation of the test microbe and mechanical removal of inoculum from a surface; rather, product efficacy is considered a combination of both attributes of a towelette-based formulation. 1.3 This test method involves the use of hazardous materials, chemicals, and infectious microorganisms and therefore should be performed only by those trained in microbiological techniques in facilities designed and equipped for work with infectious agents at the appropriate biosafety level, a BSL-2 or higher laboratory; specifications provided in the “Biosafety for Biomedical and Microbiological Laboratories” (BMBL), 6th edition (BMBL). 1.4 It is the responsibility of the investigator to determine whether Good Laboratory Practices (GLP Standards—For example, 40 CFR, Part 160 of FIFRA) are required and to follow them when appropriate. 1.5 Strict adherence to the protocol is necessary for the validity of the test results. 1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.7 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. 1.8 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.