We've all reached for the hand sanitizer to clean our hands after getting them dirty or coming in contact with a sick person -- but is it really effective at fighting the flu?

According to a new study from Japan, the influenza A virus was sometimes still active after being exposed to hand sanitizer that was ethanol-based, especially when the flu virus was surrounded by mucus -- for instance from a sneeze or cough. The researchers found when mucus was present it took 4 minutes of rubbing with hand sanitizer to effectively kill the flu virus.

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The Doctors note that 10 percent of Americans develop influenza every year, and explain that the best defense is to wash your hands for 30 seconds with soap and water.

Also, ER physician Dr. Travis Stork notes the worst place to sneeze is into your hands. He suggests using your elbow or even the inside your shirt, as we use our hands to touch nearly everything.

Watch: Can You Get the Flu, a Cold or an STD from a Toilet Seat?

Despite the possible ineffectiveness of hand sanitizer, our panel notes it is the best option when you do not have access to soap and water.