Question

Why do health practitioners recommend us to use 70% alcohol than
40% alcohol as disinfectant to fight the pandemic COVID- 19?​

Answer 1

$70$% alcohol is the perfect combination of alcohol and water to cross a cell membrane, thereby attacking the entire cell and killing the bacteria.

Explanation:

Isopropyl alcohol $70$% is pure isopropanol diluted with $30$% purified water by volume.

The benefits of using $70$% alcohol are:

• Coagulation of proteins on the surface of the cell takes place slowly, thereby permitting the alcohol to enter the cell.
• Since $70$% alcohol is a dilution of absolute alcohol, the water contained in it is essential for the denaturing process of proteins.
• Due to the difference in concentration of both water and alcohol on two sides of the cell wall, $70$% alcohol enters the cell to denature both structural and enzymatic proteins. This further increases the effectiveness of its antimicrobial properties.
• The CDC recommends $70$% for disinfecting household and routine cleaning to fight the pandemic COVID-19