What does the phrase “Kills 99.9% of Germs” REALLY mean?
This type of Marketing gimmicks are commonly used in the sales speech of many common disinfectants. It is misleading and potentially dangerous if it is the primary reason you are choosing a particular product.
Some of the most popular disinfectants sold are effective on only a small number of pathogens. Many of these products have marketing statements that say the product “kills 99.9% of germs*.” However, somewhere on the container in small print is the list of germs it actually kills, and this list of germs may or may not include some or all of the Influenza viruses.
A quick look at the label of many popular products reveals some interesting facts found in the large print of marketing and the small print of reality.
| Label Marketing Claim | Label Reality |
| Kills 99.9% of germs* | Product may kill only a small handful of different strains or types of germs, sometimes as few as only 3-4 pathogens |
| Kills in 30 seconds* | Not every organism claimed on the label is killed in 30 seconds. This statement is an especially misleading claim. Usually, it is only 1 or 2 organisms that are killed in 30 seconds. The remainder of germs claimed may take a full 5 or 10 minutes of contact time. |
The Truth About 99.9%
When a marketing claim of “kills 99.9% of germs” is used, it may or may not kill the specific variety of bacteria or pathogen you need killed.
Please check the label for the specific pathogens you need protection from.
Then what is 90%, 99.9%, 99.99%, 99.999%….
Disinfection professional today are generally concerned with what percentage of a given germ is killed by a particular process or disinfectant. The highest percentage that is generally used is 99.9999%.
So how are log rates calculated? Scientists use a logarithmic scale. Log reduction stands for a 10-fold (or one decimal point) reduction in bacteria, meaning the disinfectant reduces the number of live bacteria by 90 percent for every step.
To help understand the value of each additional “log”, let’s do the math for a small colony of a million MRSA bacteria under the edge of a patient’s table in a hospital:
- A 1-log kill reduces the colony to 100,000 MRSA bacteria after a 90% reduction;
- A 2-log kill reduces the colony to 10,000 bacteria after a 99% reduction;
- A 3-log kill reduces the colony to 1,000 bacteria after a 99.9% reduction;
- A 4-log kill reduces the colony to 100 bacteria after a 99.99% reduction;
- A 5-log kill reduces the colony to 10 bacteria after a 99.999% reduction;
- A 6-log kill reduces the colony to 1 MRSA bacterium after a 99.9999% reduction (Usually a sterilization method or procedure)
Efficacy Report of Klorkleen and Klorsept (EN standards)
