プラスチックカップを選ぶときの注意点?

Plastic cups are widely loved for their bright colors, さまざまなスタイル, 耐久性, portability, and attractive appearance. しかし, you should pay close attention when choosing a plastic cup! The bottom of a plastic cup usually has a “recyclable symbol”—a number enclosed in a triangle with an arrow. The number represents the different materials used in the cup.

Plastic cups commonly used for drinking water typically have a number 5 (pp: polypropylene) または 7 (PC: polycarbonate) on the bottom. Generally, cups with a number “5” (pp) are more heat-resistant. しかし, since the lid and cup are often made of different materials, care should be taken not to heat the lid simultaneously when microwaving. Furthermore, heating time should not be too long, as this can easily cause the cup to deform and shorten its lifespan. In addition, mineral water and purified water are also commonly packaged in plastic bottles, with a number 1 on the bottom (PET: polyethylene terephthalate).

PC is a strong and tough thermoplastic resin; its name originates from… Regarding the CO3 groups within it, the most commonly used method is the melt transesterification process (bisphenol A and diphenyl carbonate are synthesized through transesterification and polycondensation). Cups made of PC material are more wear-resistant and aesthetically pleasing. しかし, the safety of bisphenol A in the substrate remains highly controversial. Some reports suggest it can cause endocrine disorders, threatening the health of fetuses and children. Other reports have found a link between bisphenol A and obesity caused by cancer and metabolic disorders. しかし, in July 2008, the European Food Safety Authority (EFSA) released experimental data showing that when adults or infants are exposed to bisphenol A levels below the permissible level in plastics, it can be rapidly converted and… It is excreted from the body and will not harm health.

Theoretically, during the PC manufacturing process, bisphenol A (BPA) is completely converted into the plastic structure, so there is no need to worry about BPA migration during use. しかし, if a small amount of BPA remains unconverted into the PC plastic structure, it may migrate to varying degrees depending on the usage conditions. Generally, heating tends to promote BPA migration; therefore, it is not advisable to use PC plastic cups to hold boiling water (above 95℃).

As for mineral water bottles, because the PEF material is heat-resistant up to 70℃ and easily deforms, exposure to sunlight or prolonged storage in hot and humid environments can cause some substances from the PEF synthesis process, such as heavy metals like antimony, to migrate. Some residual low-molecular-weight polymers slowly migrate into the water, posing a safety hazard. Therefore, frequent train travelers and children should avoid using mineral water or other beverage bottles to hold hot water.

In general, プラスチックカップ are made from polymer materials. They are relatively stable at low temperatures and have minimal migration after short-term use, making them relatively safe for holding room-temperature, low-temperature purified water and weakly acidic beverages. しかし, under long-term use or at medium to high temperatures, these polymer materials are prone to significant migration or decomposition, releasing toxic or harmful substances. Therefore, using them to hold medium to high-temperature water is not safe. Regardless, always remember to choose qualified products!