As ethanol could be used to kill the novel coronavirus (COVID-19), many people in China has rushed to buy medical ethanol for home disinfection. However, it also brings hidden dangers. This article is going to share with you how to correctly use ethanol as a disinfection product to kill novel coronavirus. If the higher the ethanol concentration is, the better the disinfection effect is? What should we pay attention to?

 
75% ethanol is not subject to special control of disinfection products, which can effectively inactivate the virus, but at the same time, it has the characteristics of flammability, toxicity, corrosion and other dangerous characteristics. If it is not used and stored properly, it is very easy to cause fire, poisoning, burns and other safety accidents.

 
Why ethanol can kill bacteria and virus?

Ethanol is one of the most widely used disinfectants in medicine. It is soluble in water and has certain fat solubility. The mechanism of killing virus by ethanol is that its lipid solubility can destroy the biomembrane composed of biophospholipid molecules, resulting in the structure and dysfunction of biomembrane. The ethanol of relatively high concentration can destroy the structural order of the membrane, thus destroying the function of the membrane, leading to the death of "membrane" microorganisms.
 
If the higher the ethanol concentration is, the better the disinfection is?

 
The effectiveness of ethanol in disinfectants and fungicides depends on the concentration of alcohol. In order to kill 99.99% of the bacteria, the ethanol content is usually more than 60%.

 
It was found that ethanol solution with concentration higher than 60% could kill most bacteria and envelope viruses in a few seconds, but it was ineffective for bacterial spores. Among them, 75% ethanol is a common concentration, which is widely used in hospital system, scientific research laboratory and other occasions requiring disinfection.
 
However, 95% of high concentration ethanol is not as effective as dilute ethanol, 70% to 75% of which is the best. This is because the ethanol with high concentration will make the protein on the surface of bacteria coagulate to form a layer of dura, which will protect the bacteria and prevent the further penetration of alcohol. At this point, the cell will become inactive, but will not die. Therefore, 75% ethanol is a better choice.
 
Is ethanol useful to kill novel coronavirus? The novel coronavirus is a novel coronavirus of beta genus, which has envelop, and therefore can be killed by ethanol.
 
Can ethanol  be used for air sterilization?

 
Ethanol is a kind of disinfectant widely used in clinic, but it can only be used in vitro because of its high concentration, such as in hand disinfection and object surface cleaning and disinfection. In the process of home disinfection, 3 parts of pure ethanol and 1 part of water can be used to prepare 75% ethanol as the base hand polish, or spray and wipe to clean and disinfect the surface of the object.
 
At present, according to the recommendations of the World Health Organization (who), China CDC and relevant departments in China, soap plus running water is recommended for hand washing first; in the absence of hand washing materials or environment, and if there is no obvious pollution on the hands, ethanol hand polish can be used.
 
Of course, alcohol is much more convenient than soap in hospital or in outside work. This is because ethanol will volatilize quickly, and there is no need to dry the hands, which is convenient and reduces the possible pollution in the drying process. At the same time, another main use of alcohol based disinfectant is to clean and disinfect the surface of objects by spraying or wiping.
 
It is worth noting that ethanol cannot be used for air sterilization and other purposes. Some people use ethanol spray to disinfect indoor air. This practice lacks basis and cannot achieve the effect of killing virus. Moreover, the high concentration of ethanol in the air is easy to produce combustion phenomenon and cause fire. Therefore, it is not recommended to spray ethanol on the air at home. In the non-medical environment, such as the non-polluted indoor space where we live, it is unlikely that the air will be suspended enough to cause the spread of virus concentration, so there is no need for air disinfection, only regular opening of windows and ventilation.
 

Ethanol is inflammable. What should we pay attention to when using it?
 
It is understood that the flash point of 80% ethanol is 19℃ or 17.5℃. Therefore, great attention should be paid to its use, transportation and storage process. Open fire and smoking are prohibited. The more the temperature exceeds the flash point, the greater the risk of ignition. Therefore, in the use of ethanol, we should pay attention to avoid open fire, and should not spray too much in large area to avoid fire. Open fire and smoking must be strictly prohibited in production and storage areas.
 
When ethanol is used, to prevent evaporation, the maximum capacity of the container in the ward shall be 500ml, the maximum capacity in the operating room shall be 1L, and it shall be put into the wall distributor. In the healthcare system, it is recommended to provide a non-leaking pocket bottle with a capacity of no more than 100 ml and distribute it to the medical staff separately.