New Test Method for Evaluating Bactericidal Activity of Non-porous, Semi-porous, and Hydrophobic Antimicrobial Surface Products Used Indoors
1. Scope
1.1 This practice evaluates bactericidal claims for non-food-contact antimicrobial surfaces.
1.2 This practice is applicable to a wide range of surfaces, including nonporous, semiporous, and hydrophobic surfaces.
1.3 This practice is also applicable for determining the efficacy of additives containing active ingredients that are incorporated into otherwise non-antimicrobial surface materials, such as paints and coatings, by comparing a surface containing the antimicrobial agent with a surface lacking the antimicrobial additive.
1.4 The practice is intended for antimicrobial surfaces for indoor use only.
1.5 The test method simulates the deposition of wet microbe-containing droplets on a dry surface.
1.6 The practice applies to efficacy testing of antimicrobial claims but may be expanded to include viruses and fungi with appropriate modifications of preparation of inoculum and surface treatment.
1.7 The practice provides a dynamic range of greater than 5 log10 CFU/carrier, depending on the inoculum level and control condition, thereby enabling measurement of a =3 log10 reduction (LR) in culturable bacteria between test carriers and control carriers within a 2 h contact time.
1.8 Initial efficacy testing involves the evaluation of 3 lots against Staphylococcus aureus (ATCC 6538) and Pseudomonas aeruginosa (ATCC 15442). The number of lots may be adjusted according to regional regulatory requirements.
In recent years, the market has been looking for active microbiocidal surfaces that can reliably kill microorganisms to protect against cross-contamination, especially in high-traffic environments and in environments that require sterile conditions, such as hospitals.
Previous test methods were based on wet environmental conditions, which do not adequately reflect real-world contamination and the effectiveness of self-disinfecting surfaces.
ISO 7581 simulates realistic contamination of an extremely dry non-porous surface by microdroplets but may not be reliably applicable to semi-porous and hydrophobic surfaces, especially when used on fragile microorganisms.
The industry needs a test method that reliably measures the killing ability of such surfaces to answer questions from regulators about their effectiveness against a wide range of bacteria and viruses. The industry's goal is to find products with high kill properties that remain intact over a reasonable lifetime of the product.
The proposed test method strikes the balance between simulating realistic conditions and providing a robust test method for the industry and regulators.
