What is a Log Kill?

When you are dealing with biohazard cleanups of dangerous bacteria and viruses, you want to make sure that whatever decontamination product is being used is able to kill as many viruses and bacteria as possible.  However, one way you can measure the effectiveness of a decontaminate is to compare the “log kill rate.” In fact, the rate denotes how many pathogens are killed by a certain substance.

What is a log kill rate?

In fact, a log kill rate tells you what percentage of bacteria or viruses are killed by a particular substance. To figure out the rate, scientists count the bacteria before and after the substance is applied and is expressed as a whole number 0-6.

To understand the rates, consider when a number is taken to a higher power. For example:

10 x 10 x 10 = 1,000 is denoted as 103

A log kill rate is the opposite of taking a number to a higher power. In this case, instead of multiplying an amount we divide the number that many times according to the number of log kills or, in other words, move the decimal by one place for every log kill. For example, if we start with 1,000,000 C. Diff bacteria and use a sanitizing substance with a log kill rate of 1, we divide by 10 once to kill 90% of the bacteria but we still have 100,000 bacteria when we’re done. If we have a log rate of 2, we divide by ten then divide by ten again to only have 10,000 bacteria. Thus, the higher the log rate, the more effective a solution will be. However, using this methodology, the log kill rates are as follows:

Log Kill RateNumber of Bacteria LeftPercentage Killed


Georgia Clean uses decontamination products with the best log kill rate

Here at Georgia Clean, we use Tomi Steramist, which is among the best decontamination products with the highest log kill rate of 6.  You can be confident as many bacteria and viruses are killed as possible and the area is safe to use. Thoroughly trained with years of experience, our team know how to professionally apply the decontaminate to be the most effective against the threat and how to protect ourselves while doing so.

If you’re dealing with cleaning up biohazards like bodily fluids or diseases, make sure the decontaminate being used is rated as close to six as possible and that the chemicals are being properly applied by trained professionals for greatest effectiveness. Buying less effective chemicals or applying them yourself is taking a huge risk.  Your health and the health of your loved ones is worth making sure the job is done right.