CHAPEL HILL – We all know the importance of washing our hands, especially during flu season. But when we’re on the go and have to rely on hand sanitizer—it may dissolve germs and disinfect against some viruses, but not all.

Health experts warn that hand sanitizer is not effective against Norovirus, the super bug of the stomach, and that only thorough hand washing can do the job.

WCHL’s resident science expert Jeff Danner explains why that is the case.

Hand sanitizer is effective at cleaning your hands because it contains the active ingredient alcohol. Danner says that if a bacterium is immersed in alcohol, the cell membrane will dissolve, causing it to fall apart. All viruses do not dissolve as easily as germs.

He explains viruses are essentially just pieces of genetic material protected by a protein covering which are generally divided into two categories: enveloped and non-enveloped viruses.

An enveloped virus also has a layer of fats called the lipid coating on top of that protective protein covering.

“If you have an enveloped virus and you subject it to hand sanitizer— hand sanitizer is basically just alcohol in sort of a lotion—well, the alcohol will dissolve those lipids or take away that covering. Once you take the envelope off of an enveloped virus, it can no longer function.”

Norovirus, a non-enveloped virus, is a highly contagious gastrointestinal illness experienced year-around, but the number of cases usually peaks in the winter months.

“Norovirus just has that genetic material and only that protein covering which is not impacted by hand sanitizer so it won’t inactivate the virus.”

There are no vaccines or specific medications to treat the Norovirus, but hand washing can help prevent from contracting it.

“Just soap itself might not inactivate the virus, but washing your hands with soap and water can remove the virus before it infects you and have it run down the drain.” 

Many commonly used disinfectants are not effective against the illness. Health officials recommend the use of diluted bleach solution to disinfect surfaces after an episode of the Norovirus.