Lime water added to ice powder is soaked with food-grade hydrated lime powder. Its main component is a substance called calcium hydroxide, and some harmful substances are removed through processing, which is harmless. There is also a kind of quicklime, which is inedible. In fact, lime powder can be divided into two kinds: quicklime and hydrated lime powder. Quicklime is what we often use to make building materials. It is produced from natural rocks, and the limewater made from this lime is of course unusable. However, the lime we use to make ice powder is food-grade hydrated lime powder. Its main component is a substance called calcium hydroxide, and then some harmful substances are removed by processing, which is harmless.