Various sources have reported claims that blasts of hot air from hand dryers could kill the coronavirus. One video (now removed) even suggested directing this hot air up the nose. However, there is no scientific evidence behind this claim, which has been debunked by the World Health Organization.

As well as making sure that you wash your hands well, it is important to ensure your hands are dry after washing them. Wet hands transmit bacteria and viruses more efficiently than dry hands. Research shows that paper towels may be better at drying hands hygienically than warm air dryers, partly because they dry hands more quickly. People tend not to use warm air hand dryers for long enough to dry hands completely.

The best way to ensure you remove the coronavirus that causes COVID-19 from your hands is to wash them for at least 20 seconds with soap and water and to dry them thoroughly.

 

Where did the story come from?

Some media outlets report that there have been rumours that a 30-second blast from a hand drier can kill coronavirus. Other reports refer to a (now removed) video that apparently circulated on social media, in which using hot air dryers to blast hot air into the mouth and nose is recommended to kill the virus.

 

What is the basis for the claim?

There is no science behind the claim. If the virus has already entered the body through the mouth or nose, hot air will not help kill the virus or fight the infection. If the hot air dryer had become contaminated with the coronavirus by other users, then using them to blow air directly into the nose or mouth could even increase the possibility of infection.

Just blasting your hands with a hot air dryer without washing them is also not going to be enough to kill the coronavirus.

Studies of hot air dryers have focused on how effective they are at drying hands, and whether they are more or less hygienic than paper or cloth towels. There have been some concerns that hot air dryers or jet air dryers could spread germs such as bacteria, by spraying the surrounding area with fine droplets of water.

One review of 12 studies found that their results have varied. However, the researchers concluded that paper towels dry hands quickly, remove bacteria effectively and do not contaminate the surrounding area. They suggest that disposable paper towels are a better choice for healthcare settings where hygiene is of most importance.

 

What do trusted sources say?

The WHO says: “Hand dryers are not effective in killing the [novel coronavirus]. To protect yourself against the new coronavirus, you should frequently clean your hands with an alcohol-based hand rub or wash them with soap and water. Once your hands are cleaned, you should dry them thoroughly using paper towels or a warm air dryer.”

Citation

  1.  China Daily. Can using hand dryer kill the new coronavirus? 10 February 2020 https://www.chinadaily.com.cn/a/202002/10/WS5e40f8a6a310128217276537.html (Accessed 27 April 2020)

Reading list

  1. Cunrui Huang, Wenjun Ma, Susan Stack. The Hygienic Efficacy of Different Hand-Drying Methods: A Review of the Evidence. Mayo Clin Proc. 2012 Aug; 87(8): 791–798. doi: 10.1016/j.mayocp.2012.02.019 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3538484/ (Accessed 27 April 2020)
  2. World Health Organization. Myth-busters: Are hand dryers effective in killing the new coronavirus? https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public/myth-busters (Accessed 27 April 2020)