Facial Recognition Time Clocks cannot transmit germs unless they are touched. 
Only administrators need to be concerned.  Then, just wash your hands.

Cleaning and disinfecting optical fingerprint sensors:

• Use Ethanol of isopropanol in concentrations of less than 50%
  Examples: Rubbing alcohol, sanitary wipes, alcohol wipes, even what you get when you buy wings or other greasy fast-foods.
• Hydrogen Peroxide (H2O2) in a 3% solution of water - that's the over the counter one you find in all pharmacy stores and pharmacy sections.
• ...... Disconnect the clock fromthe power source
  .......Apply th eliquie to a soft lintl-free material (same as used to clean camera lenses) and gengly dab the optical sensor
• Make sure there is no residual solution left over the sensor.  If there's a sticy residue or underlying oiliness, you may use scotch taape to get rid of it by placeing it on the sensor and peeling it off.

Instructions for using Cleaning Solution

• Disconnect the clock from the power source
• Apply the liquid to a softw lint-free material (same as used to clean camera lenses) and gently dab the optical sensor.
• DO NOT pour any liquid directly on the optical sensor
• DO NOT submerge the scanner in liquid
• DO NOT rub the optical sensor with an abrasive material, including paper towels.