AOAC Use Dilution Test for Disinfectants

AOAC International (formerly known as the Association of Official Analytical Chemists) is a globally recognized, independent, not-for-profit association that develops and validates analytical methods used by regulatory agencies and industry to ensure the safety and integrity of foods, beverages, dietary supplements and other products.

The dilution method is a technique used to evaluate the effectiveness of disinfectants by testing their ability to kill specific microorganisms at various concentrations. In this method, the test substance (disinfectant) is diluted in a series of decreasing concentrations and exposed to a microbial suspension. The highest dilution that still kills the microorganisms is considered the effective concentration

AOAC Use Dilution test is applicable to liquid-based disinfectants used on hard surfaces.

The AOAC Use Dilution test takes 4-5 days to complete.

We test for AOAC Use Dilution using the following microbial strains: Pseudomonas aeruginosa (ATCC 15442), Escherichia coli (ATCC 8739), Staphylococcus aureus (ATCC 6538P), Enterococcus hirae (ATCC 10541), Klebsiella pneumoniae (ATCC 4352), MRSA (ATCC 33591), Salmonella enterica (ATCC 10708), Candida albicans (MTCC 3017). Additional strains can be added on request.

To pass the AOAC Use-Dilution Method test, a disinfectant must achieve 99.9% reduction of test organism under specified conditions. Additionally, the product must demonstrate consistent performance over multiple replicates and meet the established regulatory or industry standards for the particular type of microorganism being tested, such as bacteria or fungi.

The AOAC Use-Dilution Method involves testing on hard surfaces mimicking real-world conditions. It is designed to evaluate disinfectant efficacy against specific microorganisms. It is highly standardized, ensuring repeatability and comparability across different laboratories.

No, the AOAC Use-Dilution Method is specifically designed for testing on hard, non-porous surfaces. It may not be suitable for porous surfaces or materials that can absorb the disinfectant which could affect the test results.

Common challenges in microbial analysis include controlling variables, preparing test surfaces, managing microbial variability, and effectively neutralizing disinfectants to prevent further microbial kill during analysis.

The frequency of disinfectant product testing depends on regulatory requirements, product changes, and quality assurance protocols. It should typically be conducted during product development and before the market release. Products should also be tested periodically as a part of ongoing quality control efforts during manufacturing processes.

The AOAC Use Dilution Method is crucial for standardizing disinfectant efficacy testing approaches, ensuring safety of the product, supporting compliance, and building trust in disinfectant products, as it helps manufacturers meet regulatory and industry standards.