When you buy blueberries and many other fruits, you may have noticed that they are coated in a white-dusted power. The coating is very safe, and a natural part of the fruit. Known as the “bloom,” the waxy, silvery-white substance on grapes, blueberries, and certain plums acts as a barrier against insects and bacteria and helps to seal in the fruit’s moisture.The bloom is also a sign of freshness, since it fades with time and handling.

Although this is very safe it’s always advised to make sure you wash your fruit before consumption, to make sure any pesticides are washed away.