Potassium hydroxide is a strong base. Solutions of it, if splashed into the eye, can do irreparable damage so quickly that it is not possible to reach the eyewash fountain in time to prevent it. You must wear your goggles throughout this experiment.
Hydrogen gas is given off when aluminum metal is reacted with potassium hydroxide solutions. Hydrogen is extremely flammable. You should not use your Bunsen burner while you or others are conducting this part of the experiment.