· "Log reduction" is a mathematical term (as is "log increase") used to show the relative number of live microbes eliminated from a surface by disinfecting or cleaning. · For example, a "5-log reduction" means lowering the number of microorganisms by 100,000-fold, that is, if a surface has 100,000 pathogenic microbes on it, a 5-log reduction would reduce the number of microorganisms to one. Log Reductions 1 log reduction means the number of germs is 10 times smaller (10 1 ) 2 log reduction means the number of germs is 100 times smaller (10 2 ) 3 log reduction means the number of germs is 1000 times smaller(10 3 ) 4 log reduction means the number of germs is 10,000 times smaller(10 4 ) 5 log reduction means the number of germs is 100,000 times smaller(10 5 ) 6 log reduction means the number of germs is 1,000,000 times smaller(10 6 ) 7 log reduction means the number of ger...