Zinc oxide is a white solid. It does not dissolve in water. It reacts with acids to make zinc salts. It can react with water to make zinc hydroxide. It reacts with phosphoric acid to make zinc phosphate, a cement. It reacts with hydrogen sulfide to make zinc sulfide. It dissolves in strong bases. It can be reduced by carbon to zinc metal.
Zinc oxide can be added to concrete to help the making and hardening of concrete. Zinc oxide is used in calamine. It can be used as a deodorant and an antibacterial cream. Zinc oxide can be used as a sunscreen.
It can be added to food to add zinc to the diet. It can also be used in paint as a pigment. It also clings to certain metals better.
Zinc oxide is not toxic, but fine dust of zinc oxide can irritate the lungs when inhaled or aspirated.