Log reduction is the amount of elimination of a microbial population. It is also known as the log reduction factor. Log reduction is mostly used in the sterilization process to measure population reduction. The microbial population is affected by different factors including pH, temperature, salt concentration, etc., which are used to calculate log reduction. The decimal reduction time (D-value) and z-value for microbial populations vary according to the factors affecting microbial growth. D value or decimal reduction time is defined as the time taken by the microbial population to reduce 10fold (1 logarithmic cycle), from N0 (initial no. of microorganisms) to N/10 where N is the number of microorganisms remaining after a certain period of time.

## What is log reduction?

**Log reduction **is a method of showing the amount of elimination of a microbial population. It is also known as the log reduction factor. Log reduction is mostly used in the sterilization process to measure population reduction.

Log reduction is a measurement of the reduction in the microbial population. It is used to determine the number of bacteria or other microorganisms that are present, as well as how much has been eliminated. A log reduction factor (LRF) measures the number of organisms remaining after treatment divided by the original number before treatment. Log reduction is also known as log kill and LRKF

## Log Reduction Formula

The D value is the time taken by the microbial population to reduce 10-fold (1 logarithmic cycle), from N0 (initial no. of microorganisms) to N/10 where N is the number of microorganisms remaining after a certain period of time.

The formula for calculating the log reduction value is given below:

LR = log (\frac {Initial CFU Amount}{Final CFU Amount})## FAQ

**What is the log reduction for disinfection?**

Log reduction is a mathematical term that is used to express the relative number of living microbes that are eliminated by disinfection.

**What is log inactivation?**

“Log inactivation” is a convenient way to express the number or percent of microorganisms inactivated (killed or unable to replicate) through the disinfection process.

**What is a disinfection profile?**

A disinfection profile provides an evaluation of your disinfection practices.