AOAC Germicidal and Detergent Sanitizing Action of Disinfectants (AOAC 960.09)

The AOAC Germicidal and Detergent Sanitizing Action of Disinfectants Test Method is specified by US EPA as a method which can be used to substantiate efficacy claims for certain food-contact surface sanitizers. It is particularly appropriate for dilutable sanitizers that do not utilize halogens (chlorine, bromine).

Test Method Summary

• Cultures of a AOAC-specified Gram-negative and Gram-positive bacterium are grown in appropriate broth, and then concentrated to approximately 1 x 10^10 cfu/ml.
• In duplicate, for each microorganism, 1 ml of the concentrated culture is inoculated into an Erlenmeyer flask containing 99 ml of the test product, for the specified contact time.
• Separately, 1 ml of the concentrated culture is inoculated into an Erlenmeyer flask containing 99 ml of a non-germicidal buffer, to determine the initial concentration of microorganisms.
• After the contact time has elapsed (usually 30 seconds), aliquots of the microbe/product mixture are removed from the flask and analyzed for surviving microorganisms by dilution and plating, coupled with an appropriate chemical neutralization strategy.
• Agar plates are incubated for a sufficient period.
• After incubation, the concentration of surviving microorganisms in the test flasks is compared to that in the control (initial concentration) flasks.
• If the product kills >99.999% of both the Gram-positive and Gram-negative test microorganism, then it passes the test.

Strengths of the AOAC Germicidal and Detergent Sanitizing Action of Disinfectants Test

• The AOAC Germicidal and Detergent Sanitizing Action of Disinfectants Test is highly reproducible.
• The AOAC Germicidal and Detergent Sanitizing Action of Disinfectants Test is a great evaluation of disinfection performance in the presence of excess liquid, such as might be expected for “bulk-type” food contact sanitizing rinses (think drinking glass rinse at a bar).

Weaknesses of the AOAC Germicidal and Detergent Sanitizing Action of Disinfectants Test

• The AOAC Germicidal and Detergent Sanitizing Action of Disinfectants Test is somewhat removed from “real-life” hard surface sanitization (trigger sprayers, aerosols, etc).
• The method is somewhat operator-dependent, because the flask-swirling procedure is difficult to standardize from one operator to the next.

Microchem Laboratory has put a great deal of time and thought into perfecting the way we execute the The AOAC Germicidal and Detergent Sanitizing Action of Disinfectants Test. We enjoy performing this particular sanitizer test because the high degree of reproducibility makes comparisons between technologies more reliable.

If you are interested in setting up a study with the lab, simply contact us or request a price quote.