If you look at the news, a coronavirus has been coming a lot. In the previous article, we told you that coronavirus can be disinfected with alcohol.
This time, I will write about the alcohol disinfection in detail.
Disinfection effect of alcohol
Ethanol is the most used alcohol for disinfection and sterilization. The reason is that ethanol is the safest of many alcohols and has a high sterilizing effect.
Commercially available ethanol includes the following:
- Absolute ethanol
- Disinfection ethanol
However, “disinfection ethanol” is suitable for disinfection.
The most effective disinfectant effect of ethanol is the alcohol concentration of 70-80%, and disinfection ethanol is adjusted to this concentration.
“What? The more ethanol there is, the more likely it is to eradicate bacteria,”
some people may have thought.
However, if the alcohol concentration is too high, it will take time to disinfect.
Although ethanol has a bactericidal effect against various bacteria, as mentioned above, coronavirus is inactivated by alcohol, but norovirus is not. Some bacteria cannot be eradicated.
Next, let’s see specifically what is disinfected and what is not disinfected.
Case that can be disinfected
First, there are the following bacteria known to cause food poisoning:
- Pathogenic E. coli
- Staphylococcus aureus
- Vibrio parahaemolyticus
Ethanol is very effective against them and has a momentary sanitizing effect.
Moreover, it is also effective against the virus that has a lipid membrane called the envelope, which I mentioned before, although it is different from bacteria. For example, influenza virus, HIV virus, and coronavirus, which is a hot topic now.
Notes on use
You can disinfect! I wrote, but be careful when using it. For example, when you wash your hands and carefully disinfect them with alcohol, applying alcohol disinfectant while your hands are wet will dilute the alcohol concentration and reduce the disinfection effect. Similarly, when disinfecting things around you with alcohol, be sure to use them in a dry condition, not in a wet condition.
Also, it does not mean that things are okay because they have been soaked with alcohol! Dry them thoroughly after alcohol disinfection. In some cases, bacteria remain in the disinfectant solution due to residual water content.
Alcohol also has a bactericidal effect on the fungus mold. Alcohol is also recommended for combating black mold, which tends to occur in humid bathrooms, washrooms, window sashes, and air conditioner filters. However, since alcohol has no bleaching effect, pigmentation such as darkening due to mold cannot be removed. Also, as the environment where molds are likely to occur is inevitably moist and easy to get wet, please dry it before and after disinfection as mentioned earlier.
Cases that cannot be disinfected
The bacteria that cannot be disinfected with alcohol are bacteria that form spores, such as Clostridium perfringens, Bacillus cereus, and Clostridium botulinum.
Spores are hard shells that form inside bacteria when it is in an environment where it is not suitable for survival (high temperature environment, dry environment, poor nutritional environment, etc.). It is, so to speak, a barrier function.
Since the spores are strong, they are very resistant to drugs, heat and drying, and alcohol is not effective.
Also, this is a case of virus, but it has no effect on viruses that do not have an envelope (lipid membrane) such as norovirus.
Alcohol disinfection mechanism
Ethanol directly kills or inactivates bacterial and viral proteins by directly attacking them.
I wrote many times about that ethanol destroys the viral envelope. In the case of bacteria, it can break the cell membrane.
In addition, protein denaturation, metabolic function inhibition, bacteriolytic action, etc. can be used to eliminate bacteria.
Added on February 27, 2020
Please refer to the following article for the calculation method to adjust the alcohol concentration based on volume%.
Added on March 27, 2020
I wrote an article about the difference between industrial IPA and disinfection IPA.
Added on April 17, 2020
Even if you know the ingredients, there is what you may not know.