Killing Viruses

Products like alcohol-based hand sanitizer, soap, and bleach, can often destroy or kill virus particles.

Alcohol-Based Hand Sanitizer

Alcohols can destroy virus particles by disrupting the outer membrane of membrane-bound viruses (including the coronavirus, and the influenza virus). Alcohols like ethanol and isopropanol can permeate between the phospholipids in biological membranes and disrupt the structural integrity of the lipid bilayer membrane structure. Viral membranes are critical to their function, often serving as the medium in which viral spike proteins are situated. If a virus particle’s membrane is disrupted, the particle will lose the ability to attach to and invade a prospective host cell.

Some of the earlier records of alcohols being used as a disinfecting agent in the United States date back to the Civil War to treat battle wounds.

Soap

Soaps operate in much the same way as alcohols: soap molecules integrate themselves into phospholipid bilayer membranes, thereby disrupting their structural integrity. Soaps like sodium stearate are able to do this because like phospholipids, sodium stearate molecules have both hydrophilic heads and hydrophobic tails, in essence mimicking the general structure of phospholipids.

As the soap molecules break apart a membrane, they tend to isolate membrane proteins into protein-detergent complexes, which completely neutralizes any impact that a viral particle may have otherwise had.

Bleach

Bleach is a much more aggressive agent for killing viral particles. In fact, bleach is so corrosive that it can pose a danger to human skin, or any part of the human mouth or digestive tract that it comes into contact with.

The key molecule in bleach is sodium hypochlorite, which dissociates readily in water. When this happens, the sodium ion and hypochlorite portion break apart from one another. The hypochlorite portion will form hypochlorous acid which can denature (or “destroy”) proteins that it comes into contact with – including the spike protein of viruses!

When the viral spike proteins of the coronavirus or influenza virus are neutralized, the viral particles can no longer invade or infect human cells. But as mentioned, bleach can be incredibly harmful to humans, with the potential to cause chemical burns on any regions of skin it comes into contact with, and significant internal damage if ingested.