السر المخفي في قاع الزجاجة

We often use a series of plastic bottles, bowls, cups and other containers in our life. The bottom of these containers usually has a triangular clockwise arrow mark, with an Arabic number in the middle. Do you understand the meaning of these logos? Misuse can seriously affect health and even cause cancer.

The Arabic number of the general logo is 1-7, representing seven plastic models. It is the seven recycling logos of plastic products formulated by the relevant agencies of the plastic industry in the United States. The main role is to serve as a recycling mark, facilitate the classification of recycling, not representing the level of food safety. No. 1 PET (polyethylene terephthalate), No. 2 HDPE (high density polyethylene), No. 3 PVC (polyvinyl chloride), No. 4 (low density polyethylene), No. 5 PP (polypropylene), No. 6 PS (polystyrene), No. 7 other categories (mainly PC polycarbonate, PA nylon).

Of the seven signs, can be used as water cups or beverage packaging is:

No. 1 (PET): mineral water bottle, soda bottle, etc. Above 70 degrees is easily deformed, so it can't be used to fill hot water. In addition, PET water bottle may release carcinogen DEHP after 10 months, so try not to reuse it, especially for some frugal elderly people, who are accustomed to using old mineral water bottles to separate oil or wine, it is better to use glass bottles instead.

No. 5 (PP): Common soymilk bottles, yoghurt milk bottles, juice beverage bottles, microwave oven lunch boxes, etc. Because PP material can withstand the highest temperature of 167 ℃, the plastic container made of PP can be used in microwave oven, and after cleaning, it can be reused. Therefore, the plastic water bottle made of PP can be used to hold hot water and can be used many times, but it is not recommended for long-term use.

No. 7 (Others): In other plastics, the common PC can be used as a water bottle. Basically, the water bottles and space cups sold in shopping malls are mainly made of PC materials. PC material is non-toxic, and can generally withstand 130 C high temperature. But the quality of PC produced by different companies and producing areas will vary. Some PC materials may remain carcinogenic bisphenol A in the production process, so most countries now prohibit the direct use of PC materials as infant products. The higher the temperature is, the more the residual bisphenol A in PC is released and the faster it is released. Therefore, boiling water in PC water bottles should be kept as little as possible. If the water bottle you use is made of PC, pay attention to the following usage methods: don't heat it, don't direct sunlight, don't wash it with dishwasher. When used for the first time, it is washed with baking soda powder heated water and dried naturally at room temperature.