General screening test, disinfection, (use dilution), screen

This test meets FDA and EPA criteria for testing hard surface disinfectant efficacy against Staphylococcus aureus, Salmonella cholerasuis, and Pseudomonas aeruginosa dried onto stainless steel penicylinders. A 95% confidence level can be obtained by demonstrating kill of 59/60 replicates for each organism on three different lots of product.

Study Outline

The AOAC use-dilution test is performed for hard surface disinfectant activity against Staphylococcus aureus, Salmonella cholerasuis, and Pseudomonas aeruginosa. Germicides are generally single use products and are to be tested against worse-case conditions (hard water, organic soil or serum, pH, etc.).

The procedure is outlined in the Association of Official Analytical Chemists (AOAC) Use Dilution Test methods 955.14, 955.15, and 964.02 and is required by the United States Environmental Protection Agency Office of Pesticide Programs DIS/TSS documentation for some applications, and the United States Food and Drug Association Content and Format of Pre-market Notification [510(k)] Submissions for Liquid Chemical Sterilants/High Level Disinfectants.

Aliquots of disinfectant solution are placed into tubes. Stainless steel penicylinders are contaminated with the test organisms and placed into the product tubes for the specified time interval (selected by the sponsor). After the appropriate exposure time, the carriers are removed and placed into a neutralizer media. The media is incubated and observed for growth. This is repeated for each organism and submitted lot of product.

A neutralization study is completed for each organism and sample type to demonstrate the ability of the media to support organism growth.

Sample Requirements

Organisms: S. aureus, S. cholearaesuis, P. aeruginosa

10 Carrier Screen, 1 organism = 200-250 milliliters per lot minimum

1 Lot Screen, 3 organisms, 60 carriers each = 3-4 liters, minimum

Full Test, 3 organisms, 60 carriers each, 3 lots = 3-4 liters, per lot minimum

Note: These are final test volumes, dilutions can be made by the laboratory from submitted concentrates. Dilutions for sample preparation are to be included in the test protocol.

Nelson Experts:

• Kimberlee Dickman 801-290-7858, 800-826-2088

Sample Requirements

Organisms: S. aureus, S. cholearaesuis, P. aeruginosa

10 Carrier Screen, 1 organism = 200-250 milliliters per lot minimum

1 Lot Screen, 3 organisms, 60 carriers each = 3-4 liters, minimum

Full Test, 3 organisms, 60 carriers each, 3 lots = 3-4 liters, per lot minimum

Note: These are final test volumes, dilutions can be made by the laboratory from submitted concentrates. Dilutions for sample preparation are to be included in the test protocol.