Sanitizer Test for Inanimate Surfaces
EFFICACY DATA REQUIREMENTS
Sanitizer Test (for inanimate, non-food contact surfaces)
(Proposed method prepared by Registration Division, Office
of Pesticide Programs, EPA, 1976)
- Test requirements.
- Three product samples, representing 3 different preparations, one of which is at least 60 days old, should be tested against each test bacterium on each test surface. The test bacteria are Staphylococcusaureus ATCC 6538 and Klebsiella pneumoniae, aberrant, ATCC 4352. Enterobacter aerogenes (ATCC 13048 or 15038) may be substituted for K. pneumoniae. The test surface(s) represent the type(s) of surfaces recommended for treatment on the label including, but not limited to, glass, metal, unglazed or glazed ceramic tile, porcelain, or vitreous china. The propagation of cultures and use of subculture media and other related equipment may be as specified in Sec. 4 (Disinfectants) of the Official Methods of Analysis of the A.O.A.C., 12th ed. (1975).
- Determine the bacterial count in an 18- to 24-hr broth culture and add 0.01- to 0.03-ml of the broth culture by spreading on a 1 x l-in. square of the test surface using a bacteriological loop. If the product is to be represented as a "one-step" cleaner-sanitizer, an appropriate organic soil load, such as 5% blood serum, must be added to the bacterial inoculum. The square should be dried for 40 min. in a bacteriological incubator at 30-37C. A "zero time" bacterial numbers recovery determination should be performed and reported to show the number of viable bacteria on the test surface after drying. The product is applied to the inoculated test squares as directed on the label. Parallel tests are run on the formulation with the active ingredient(s) omitted in an identical manner to serve as controls. If such a control solution is impractical, use sterile distilled water to which may be added 0.01% isooctylphenoxypolyethoxyethanol (with 9-10 moles oxyethylene, e.g., Triton X-100). After a suitable time interval, recover the test bacteria by washing the square with adequate agitation in appropriate media or dilution fluid containing appropriate neutralizers. Make plate counts in appropriate nutrient agar containing the same neutralizers by the pour or spread plate technique. Exposure time intervals between zero time and five minutes must be tested for the product as well as for the untreated controls.
- Performance requirements.
The results must show a bacterial reduction of at least 99.9% over the parallel control count within 5 minutes.