Log reduction = Risk Reduction

Log reduction is one of our favorite phrases around here, separating fact from fiction and has wide leaning implications. Essentially, log reduction is a scale to measure how much a disinfectant can kill. People feel like if their disinfectant/UV light/ Ionizer or other product kills 99.9% of a germ that it’s a really good disinfectant. Well, if you start out with a population of a million (which isn’t really that much in the germ world) and you kill 99.9% of the germs, you would still have 1000 organisms left behind on the surface. In the case of SARS CoV1, an infectious dose of some organisms can be as little as 67. Basically, the more nines after the . the more organisms are being killed. According to the EPA, disinfectants need to have a baseline of 99.99%(4 logs) of bacteria. At CURIS, our vapor hydrogen peroxide kills 99.9999(6 logs). So, if you have a 99.9% (3logs) kill on your disinfectant, is it really a disinfectant or is it just a sanitizer?