How to Choose a Safe Cup

In our daily lives, cups are among the most commonly used items, whether for drinking coffee, tea, beverages, or during office work, travel, and exercise. The cup we drink from is our mouth’s closest “friend,” so using an unsafe cup can lead to the unintentional ingestion of harmful substances. Faced with a wide variety of cups on store shelves, how can we choose wisely? Let’s dive into some key considerations.

1. Stainless Steel :Stainless steel cups are made from alloy materials, which, although generally stable, can vary in quality based on the materials used. Some manufacturers may mix in low-quality metals to save costs, which can release heavy metals, especially when used with hot drinks, posing health risks. Avoid using metal cups for acidic drinks like juice, coffee, and carbonated beverages, as they can react with metal. Additionally, stainless steel cups cannot be used in the microwave, which can be inconvenient. So, when choosing stainless steel, pay attention to the quality and materials used.

2. Glass Cups :Glass is one of the safest materials for cups, but low-quality glass can still pose risks. Check the glass for bubbles or granular impurities; if present, the material may be impure or even contain lead, which could be harmful when in contact with hot drinks. Opt for high-borosilicate or soda-lime glass, which is lead-free and safe for use.

3. Plastic Cups and Disposable Cups:These cups are not always safe, especially when used with hot drinks, as they may release harmful substances. In general, they’re not recommended for regular use.

4. Enamel Cups:Enamel cups have a layer of glaze applied to metal and fired at high temperatures. This glaze may wear off over time, especially if frequently scratched, and metal quality beneath may be uncertain. Additionally, enamel cups are not suitable for acidic liquids, as they can rust over time.

5. Ceramic Cups :Ceramic has a long history in China, with many types of craftsmanship. In general, “ceramic” encompasses both earthenware and porcelain. Earthenware is made from natural clay fired at temperatures between 800℃ and 1250℃ (1472°F - 2282°F), with small pores and slight water absorption; while porcelain is made from clay, feldspar, and quartz, fired at 1200℃ - 1400℃ (2192°F - 2552°F), with a dense, hard body and a resonant sound.                                                                                                                                                                                                                          There are many manufacturing processes for ceramics, but several factors related to our health and safety need to be taken seriously and need to be referenced when choosing ceramic mugs.
   1. Try to choose stoneware mugs, because its firing temperature is high, although the appearance looks a bit rough.
   2. Try to choose ceramic mugs or stoneware mugs with underglaze colors, because the painted pigments are under the glaze, and after high-temperature firing, its chemical composition is stable, very durable and heat-resistant, and suitable for any liquid beverages.
   3. For ceramics with glaze colors, it is also safer, because the painted pigments are hand-painted in the middle layer, and the outside will be covered with a layer of glaze before firing.
   4. For overglaze colors, this kind of ceramic mug is not recommended for purchase. Because in history, overglaze colored ceramics were mostly for viewing and collection, and were not suitable for daily use in the kitchen. There are many such overglaze colored cups on the market now. If you feel obvious unevenness when you touch the surface of the cup, please discard it. Especially now that many technologies can directly print patterns on the inside and outside of the cup, it looks cool, but it is actually very unsafe.
   
   So, how should we understand this process? For the sake of beauty, artists will paint on the ceramic body before firing. Underglaze color means hand-painting patterns directly on the body, then soaking a layer of glaze on the outside, and then firing; in-glaze color means soaking a layer of glaze on the body first, painting after drying, then soaking in glaze again, and then firing; overglaze color means soaking a layer of glaze on the body first, painting after drying, and then firing. Please refer to the figure below:

Here is the updated comparison table for underglaze, in-glaze, and overglaze techniques:

After comparative analysis, it is not difficult for us to draw a conclusion: ceramic glazed mugs are the first choice for safe and heat-resistant mugs. After further elimination, stoneware mugs with underglaze color technology are the safest choice.
1. It is a thick stoneware mug for hot drinks. The material molecules are very stable and resistant to high temperatures. It can be used in microwave ovens, ovens, and dishwashers.
2. Stoneware mugs are very durable and generally thicker. The glaze is fired at high temperature to form a transparent glass glaze protective surface on the surface, which can prevent all scratches.
3. High density, non-absorbent, easy to clean.