Buying bottled drinks to quench their thirst has become a habit of many people. However, in recent years, some scholars have discovered that plastic beverage bottles will release heavy metals and soak into the beverage. As the soaking time increases, the amount released will increase. Is it safe to drink bottled drinks? How are these beverage bottles made?
Recently, food safety issues have become more and more highly concerned, but containers containing food and beverages should not be underestimated. Many people are accustomed to buying bottled beverages to quench their thirst. However, according to research, plastic beverage bottles will release heavy metal barium, which is detrimental to human health. What problems should be paid attention to when drinking plastic bottled drinks?
Not only polymers but also various additives
Plastic beverage bottles are produced by the esterification reaction of terephthalic acid [C6H4(COOH)2] and ethylene glycol [C2H4(OH)2] monomers. To undergo the esterification reaction, both must first be dissolved in an organic solvent. In order to accelerate the reaction, in general, antimony trioxide (Sb2O3) is used as a catalyst to reduce the energy, temperature, and pressure required for the reaction.
Bottled beverages such as mineral water, juices, and green tea are available on the market. Bottles have different levels of softness and hardness, and are mainly related to the molecular weight of polymers and the arrangement of PET. The number of PET bottles connected to a plastic beverage bottle does not have a fixed number. Its molecular weight can range from thousands to millions. In general, the longer the molecular connection, the harder the material. In addition, the more neat the PET is arranged, the harder the bottle is.
The material of the plastic beverage bottle is colorless and transparent. Some manufacturers add color materials for the design to make the bottle color. In addition, chemicals such as light stabilizers, antioxidants, and stabilizers are added to increase their useful life.
Will it be released?
In 2006, Prof. William Shotik found that after three months of plastic bottle placement, the content of heavy metal barium increased from 360 ppt to 630 ppt. Relevant experts said that plastic beverage bottles do release heavy metal cesium, and the source is the catalyst used in the manufacturing process, "Antimony trioxide." Because it cannot be recovered 100% under current technology, trace amounts of niobium will remain. For this reason, a few manufacturers have switched to using safer titanium oxide as a catalyst. However, if the beverage is stored in a low-temperature environment, the amount of released cerium should be controlled within a safe value, but if exposed to sunlight for a long time, PET may release more helium due to decomposition. Toxic medical experts say that a large number of warts can cause headaches, nausea and other symptoms, and the amount of 630 ppt is quite low for the human body, so it is difficult to conclude that there will be any harm to the human body. There is no case of poisoning due to drinking bottled beverages.
Will plasticizers be released?
Some plastic products will be added during the manufacturing process plasticizer phthalate ester, it belongs to environmental hormones, will affect the biological physiology or even cancer, plastic drinks bottles add this compound? Experts pointed out that plasticizers are used to increase the ductility and flexibility of polymers. They are mainly added to cling film, PVC film, or elastic plastics. Plastic beverage bottles do not contain phthalates. Its molecular structure has not changed and can be reused without heating, excessive illumination or microwaves.
Is it safe to hold rice wine?
Some commercial rice wines are also packed in plastic beverage bottles. Experts say that alcohol easily dissolves organic substances such as antioxidants and light stabilizers. These additives usually dissolve into rice wine within two days. Therefore, there is a certain amount of plastic bottled rice wine. risk.
The easiest way to safely drink bottled beverages or to reuse plastic beverage bottles is to avoid light and heat during storage. Once the anti-photoresist and antioxidants are consumed, PET begins to decompose or chemically react with other substances. The various poisons in PET will be released.
Links How to Interpret Plastic Material Numbers
Many plastic bottles are marked with the triangles 1-7, which represent plastics of different materials. Is the larger number safer? What should you watch out for when using them to hold food?
Relevant experts said that the bigger the number, the more secure the concept is wrong. 1-7 represent the plastics of the first to seventh categories, the most problematic being the third category of polyvinyl chloride (PVC). In addition to chemical substances added during the manufacturing process, they cannot be recycled and will produce dioxins when burned. And chlorine-containing compounds have a great impact on the environment, so many countries have reduced or prohibited their use.
The sixth type polystyrene (commonly known as polystyrene, PS) has poor chemical stability and can be dissolved by various organic solvents. During the manufacturing process, many chemicals are added to improve stability, and these additives may be accidentally Was eaten in the stomach.
The seventh type of plastic refers to plastics other than those in the first to sixth categories, of which the most problematic is polycarbonate (PC). The raw material of PC is bisphenol A (bisphenol A, BPA). The biggest problem is not chemical substances added during manufacture, but the material itself will release bisphenol A. Some high-efficient detergents even dissolve bisphenol A in PC. When the surface of the container is scratched, bisphenol A will dissolve into the beverage. Bisphenol A is an environmental hormone. It has been found in animal experiments that as long as 3 ppb (ie, 1 microgram of water contains 3 micrograms) of bisphenol A, the cells will be abnormal. According to experts, bisphenol A is known to reduce the number of spermatozoa, damage to the cranial nerves, or abnormalities of prostate cells. A recent survey by the Amer-ican Medical Association found that urinary double Those with higher levels of phenol A have a higher risk of cardiovascular disease or diabetes than the average person. However, this report is only a preliminary investigation. Why is there such a result? We must further study it.
Experts said that the first type of plastic is PET, as long as the use of care not to be exposed to light and to avoid exposure to high temperatures. Among the seven types of plastics, the second, fourth and fifth categories are safer. The second category is high-density polyethylene (HDPE), and the fourth category is low-density polyethylene (LDPE). These are all formed from C2H4 polymerization. HDPE hardness is higher than that of LDPE, and its structure is relatively stable and safe. The sex is also higher. The fifth category is polypropylene, a C3H6 polymer. These three types of polymers have no oxygen atoms and do not react easily with sunlight or air. Therefore, the chemical structure is relatively stable and has a long service life. Even if the surface is scratched, it will not release poisons. The colors of these three types of plastics are all slightly transparent in white. If colorants are added during the manufacturing process to make them change color, they should be avoided as much as possible. As far as plastics safety is concerned, as long as we pay more attention to the above points, we should be able to avoid most of the poisons.
Reprinted: Chinese bottle net
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