Among all the cups made of materials, the glass is the healthiest. This kind of glass contains no organic chemicals in the firing process. When people drink water or other drinks from glasses, they don't have to worry about chemicals being drunk into their stomachs. Moreover, the glass surface is smooth and the glass wall is transparent, so it is easy to find dirt, and it is easy to clean if there is dirt. Bacteria and dirt are not easy to breed on glass walls, so it is the healthiest and safest for people to drink water from glasses.
However, although glass contains no chemicals and is easy to clean, users can easily burn themselves because of the strong thermal conductivity of glass materials. If the water temperature is too high, the glass may burst, so try to avoid holding hot water.