Hand hygiene plays a major role in reducing the transmission of any germs. Hand dryers are seen in restrooms commonly nowadays. There has been speculation that hand dryers might be able to kill Coronavirus, especially as it blows warm air out. In this article, we will review existing evidence and conclude if this is a fact.
According to a study published in Medical Microbiology and Immunology, heat treatment at 600 C for at least 30 minutes must be used to completely inactivate SARS Coronavirus, a close cousin of Novel Coronavirus. At a lower temperature, the SARS virus was still infective depending on the type of the surface where the virus was located. Another study published in the Journal of Influenza and other Respiratory Viruses, heat inactivation of MERS Coronavirus was researched. Temperature of 650 C for 25 minutes was required to have a strong negative effect on viral infectivity.
Using a hand dryer, it is not possible to reach 600 C. It is also not possible to use hand dryer for 30 minutes. On the other hand, few studies demonstrated that viruses may get dispersed when hands are not properly washed and hand dryers are used. In one study published in the Journal of Applied Microbiology, participants' gloves were contaminated with a surrogate for human viruses. Participants then dried their hands using a warm air dryer or jet air dryer or paper towel. It was concluded that using hand dryers caused significantly higher dispersal of viruses when compared to paper towels. Similarly, studies published in the journal of Hospital Infection and the journal of Infection Control and Hospital Epidemiology concluded that bacteria are dispersed more into the environment when air dryers are used.
These studies underscore the importance of handwashing thoroughly using soap and water. If soap and water are not used or if hands are not washed thoroughly for at least 20 seconds, viruses and bacteria can be dispersed into the environment, especially when hand dryers are used. In summary, hand dryers cannot kill Novel Coronavirus. If hands are not washed thoroughly with soap and water, hand dryers may even disperse virus into the environment increasing the risk of infection.
Kimmitt PT et al. Evaluation of the potential for virus dispersal during hand drying: a comparison of three methods. J Appl Microbiol. 2016 Feb;120(2):478-86. doi: 10.1111/jam.13014.
Best EL et al. Microbiological comparison of hand-drying methods: the potential for contamination of the environment, user, and bystander. J Hosp Infect. 2014 Dec;88(4):199-206. doi: 10.1016/j.jhin.2014.08.002. Epub 2014 Aug 27.