1. Glass Cup<br />almost liquid state when heated sufficiently - and it can transform back into the solid amorphous state by cooling; hence it's 100% recyclability. (Figure 1) The glass does not contain organic chemicals during the firing process. Glass is made entirely from natural raw materials that are toxicologically inert. The major constituents, i.e., sodium/potassium silicates, are non-toxic and chemically highly inert. The transfer of silicates and cations into food is marginal and, even if it occurs, is toxicologically irrelevant since the cations usually present are non-toxic. Virtually no traces of problematic migrants originating from the glass are found in glass-bottled food products. When people drink a glass or other beverages, don't worry about chemicals being drunk. Moreover, the glass surface is smooth and easy to clean. Bacteria and dirt are not easy to be born on the cup wall, so it is the healthiest and safest to drink with a glass. <br />2. Plastic Cup<br /> During the manufacturing process of plastic polymers, polymerization is incomplete. Therefore, mono- and oligomers frequently are present in the food packaging materials (FPMs) and can migrate into the food, e.g., EU legislation lists hundreds of chemicals’ possible migration from plastic polymers into food. A prominent example is acrylamide, a rodent carcinogen and neurotoxic agent in many species including humans. Acrylamide is required for the production of polyacrylamide polymers, which may also be used in FPMs (Figure 2). Other examples of monomers migrating into food are styrene, vinyl-chloride etc. Although the levels migrating into food items under standard conditions are regulated and controlled, a certain degree of migration is virtually unavoidable. Plastic cups are also an unwelcome one. Because plastics are often added with plasticizers, which contain toxic chemicals, toxic chemicals can be easily diluted into the water when hot water or boiling water is used in plastic cups. And the internal microstructure of the plastic has a lot of pores, which are easy to hide the dirt, and it is easy to produce bacteria when it is not cleaned. A relatively large number of chemicals are intentionally added to the plastic polymers and may eventually leach into the water. Plastifiers are an important group of materials that are intentionally added during the manufacturing of plastic polymers. Most notably, bisphenol A, a widely used plastifier, has been accused of acting as a so-called ‘endocrine disruptor’, i.e., a synthetic chemical that can affect functions of the endocrine system pivotal for development, reproduction, and many other vital functions of the organism. Therefore, when purchasing plastic cups, be sure to choose a cup made of food-grade plastic that meets national standards. In the conclusion part, the safest cup is glass and the least safe is a plastic cup. <br />