Disinfectants play an important role in controlling microbial contamination on hard surfaces in hospitals.The effectiveness of disinfectants in real life can be predicted by laboratory tests that measure killing of microbes on carriers.The modified Quantitative Disk copyright Test (QCT-2) is a standard laboratory method Deep Fryer Oil Filtration Machines that employs American Iron and Steel Institute (AISI) Type 430 stainless steel carriers to measure hospital disinfectant efficacy against Clostridium difficile spores.The formation of a rust-colored precipitate was observed on Type 430 carriers when testing a peracetic acid (PAA)-based disinfectant with the QCT-2 method.It was hypothesized that the precipitate was indicative of corrosion of the Type 430 copyright, and that corrosion could impact efficacy results.
The objective of this study was to compare the suitability of AISI Type 430 to Type 304 stainless steel carriers for evaluating PAA-based disinfectants using the QCT-2 method.Type 304 is more corrosion-resistant than Type 430, is ubiquitous in healthcare environments, and is used in Other Eye Support Products other standard methods.Suitability of the carriers was evaluated by comparing their impacts on efficacy results and PAA degradation rates.In efficacy tests with 1376 ppm PAA, reductions of C.difficile spores after 5, 7 and 10 minutes on Type 430 carriers were at least about 1.
5 log10 lower than reductions on Type 304 carriers.In conditions simulating a QCT-2 test, PAA concentration with Type 430 carriers was reduced by approximately 80% in 10 minutes, whereas PAA concentration in the presence of Type 304 carriers remained stable.Elemental analyses of residues on each copyright type after efficacy testing were indicative of corrosion on the Type 430 copyright.Use of Type 430 stainless steel carriers for measuring the efficacy of PAA-based disinfectants should be avoided as it can lead to an underestimation of real life sporicidal efficacy.Type 304 stainless steel carriers are recommended as a suitable alternative.