In your own words, give two reasons why is it important to wash your hands both before and after completing a lab

Before: To make sure your hands are clean and free of dirt before you touch whatever you are dealing with.

After: To get any harmful chemicals off your hands so you don't infect anything or yourself. 

It's Important to wash your hands before because you need to get the dirt off your hand because it might mess up the lab results and after is because you need to get the chemicals off your hands