Wash your hands ... and DRY THEM, too.

By Simon Shapiro

We're being bombarded with the very sensible advice to wash our hands constantly. It's the first line of defense against the COVID-19 virus. And it's critical to wash properly: enough soap and water, lots of friction, spend 20 - 30 seconds (sing 'Happy Birthday' twice through) etc. But even after a diligent washing, your hands are probably not perfectly clean. After a less-than-diligent washing, your hands are definitely not perfectly clean. Drying them properly should also be part of the routine, for three reasons:

1.  Drying your hands can remove some (or even most) of the residual bacteria and viruses.
2. Wet or damp hands provide an environment that's good for residual bacteria and viruses (and therefore bad for us).
3. Damp hands are more likely to transmit residual bacteria and viruses to other surfaces. 

In 2012 the Mayo Clinic published a survey of twelve studies looking at the effectiveness of different drying methods. Methods included cloth or paper towels, hot air dryers and jet dryers. (Jet dryers are the newer kind that use a strong, loud jet of unheated air).

Not all of the studies agreed with each other, but the overall conclusions are clear.

• Towels and jet dryers get hands 96% dry in ten seconds. Hot air dryers need 40 seconds to get to that level.
• We're usually in a hurry and don't take enough time to dry our hands. We spend 3-5 seconds on a towel and around 15 seconds on a hot air dryer. On average men are worse than women, and get to only 55% dryness on a hot air dryer; women average 68%. But both get to at least 90% using towels.
• All methods are very effective if used properly. 

  The takeaway advice is clear:

• Wash your hands frequently and carefully.
• Dry them thoroughly every time. 
• If you're using a multiple-use towel (as you likely are, at home), bear in mind that it's getting residual bacteria and viruses, so launder and change it frequently.