So you wash your hands in the restroom, make sure to use a paper towel to open and close the door, return to your seat and buckle your seatbelt. Later you adjust your air vent and open your tray table. Then you dig your fingers into your bag of pretzels. Did you thoroughly sanitize all these things first before you handled them? Oops. Hand sanitizer is your friend on an airplane. Dirtiest Places on Airplanes: How to Avoid Germs | Time