Use-Dilution Test for Disinfectant

Summary of the Use-Dilution Test for Disinfectant

AOAC use-dilution method is a method for testing the efficacy of disinfectants. This method was originally developed in 1955 and has been revised several times. It has now become the standard for evaluating liquid and dilutable liquid disinfectants for hard surfaces. One of the most recent revisions to this method is the result of years of work by industry members and the U.S. Environmental Protection Agency, which lowered the performance standards for Staphylococcus aureus and Pseudomonas aeruginosa, making the pass/fail determination of the test more reliable. The EPA stipulates that the use-dilution method is a required method for disinfectant claim substantiation.

In the use-dilution method, penicylinders are used for the disinfection efficacy test. These penicylinders are called "carriers" in the AOAC method. The experiment process is as follows: soaking stainless steel carriers in bacteria, treating them with disinfectant, and put the carriers in the growth broth to determine whether there are still surviving bacteria. Standard testing uses 60 carriers to test the efficacy of the disinfectant against different organisms and at different time points. The result of this method depends on whether the bacteria are growing, not by enumerating the bacteria.

The Use-Dilution Test for Disinfectant Provided by Creative BioMart Microbe

Currently, Creative BioMart Microbe can implement 3 different methods proposed according to the required test organisms, including:

• AOAC 955.14 tested against Salmonella enterica
• AOAC 955.17 tested against Trichophyton mentagrophytes (fungi)
• AOAC 955.15 tested against Staphylococcus aureus
• AOAC 964.02 tested against Pseudomonas aeruginosa

Depending on the purpose of the test, there are specific performance requirements to determine whether the disinfectant passes/fails, which is dependent on the number of carriers that demonstrate complete disinfection after incubation when the growth of the target organism is recorded.

• Salmonella: at least 59
• Staphylococcus: at least 57
• Pseudomonas: at least 54

* It is strongly recommended to confirm the regulatory requirements with the appropriate agency before testing.

The AOAC use-dilution test is approved by the EPA and for data submission in conjunction with registration of dilutable disinfectants sold in the US. And the AOAC use-dilution test is a "high level" for disinfectants, which means that an antimicrobial solution must have considerable biocidal activity in a relatively short time to pass the test. However, due to the ambiguity of the official method, this method may be subject to additional variability, and there is a difference between AOAC use-dilution testing and the "real life" use of disinfectants.

Creative BioMart Microbe provides high-quality use-dilution tests for disinfectants. Our experienced researchers and powerful technology platform can ensure the accuracy and repeatability of test results.

If you want to know more about this service, please feel free to contact us by phone or email, or you can consult through our inquiry form. We will ensure to provide you with efficient and high-quality experimental outsourcing services.