During the New Year's Day holiday, the message “10 times more than the formaldehyde in the tape of vegetables bound with vegetables” was spread in the circle of friends. The enthusiastic readers also called the reporter to verify the authenticity. Recently, reporters purchased 9 samples from supermarkets and street-side food stores. No formaldehyde was detected. Experts said that some vegetables themselves contain formaldehyde, which is harmless to the human body. “The national standard does not impose a limit on the formaldehyde content of vegetables. However, the adhesive in the tape may contain formaldehyde auxiliaries or plasticizers. It does not apply to foods. Packaging: It is recommended that the public try to remove the part that comes into contact with the tape when cleaning the vegetables."
(Ancestral Hall)
Adhesive tape bundled vegetables excessive formaldehyde?
During the New Year's Day holiday, the reporter received a number of WeChat letters from eager readers. “Tape-bound vegetable formaldehyde exceeded the standard by 10 times.” Everyone asked if such "formaldehyde vegetables" could not be eaten. The reporter search query found that this message appeared as early as 2014, and it appeared again in 2015. At the New Year holiday in 2017, the corresponding video appeared again and spread in a circle of friends. Is the formaldehyde really large enough to exceed the standard? Recently, the reporter visited supermarkets and found that many vegetables were bundled with tape. Some net dishes were directly packed in plastic boxes. Celery, young bamboo shoots, etc. were first wrapped in plastic wrap, and the price tag was put on the plastic wrap. Leaf vegetables are covered with small rubber bands. The tape is mostly blue with text printed on it. For such a vegetable, an old grandfather said, "Generally, the food is washed, but the ordinary people can not come."
Citizens have different attitudes. One aunt said, “Surely it is not good. Is it not that formaldehyde is exceeded? Is it not the same as the tape used for express delivery? Our homes are cut with scissors, especially for cold dishes. It's wasteful."
Subsequently, the reporter sent 9 samples purchased from the Beijing market for inspection, of which 7 were from chain supermarkets and 2 from street restaurants. Only one of the nine samples was not tied with tape.
Expert opinion: Some vegetables themselves contain formaldehyde, and there is no standard limit
Of the 9 samples tested, none of the sample test liquids with unbound tape showed pink or purple, demonstrating that no formaldehyde was detected. In the 8 tape-bound vegetable control samples, no contact with the tape portion of the vegetable and the contact tape portion of the vegetable control sample detection solution showed no pink or purple color, which means that no formaldehyde was detected. Dr. Zhang Yuping, a technical manager of Beijing Zhiyunda Food Safety Testing Consumer Experience Center and a graduate of the Agricultural University of China, told reporters that some food products also produce a certain amount of formaldehyde, which is called endogenous formaldehyde. Studies have found that some aquatic products, vegetables, fruits, meats, milk, etc. will produce endogenous formaldehyde, and the formaldehyde produced by different vegetables will vary greatly, with only a few milligrams per kilogram of vegetables, such as about 4 milligrams in white radish. Many can reach tens of milligrams, such as about 25 milligrams in broccoli, and fresh mushrooms in mushroom vegetables can even reach about 200 milligrams. At present, there is no relevant standard for the endogenous formaldehyde content of plants. We need not worry about it. “In this test, no formaldehyde was detected in all the samples, indicating that it was not credible that the tape was bound to exceed the standard for formaldehyde in the vegetables. However, the security of the tapes is also a concern for all.” said Zhang Yuping.
There is no standard supervision tape in the tape packaging
Zhang Yuping told reporters that the tape used for bundling vegetables is generally made of polypropylene film as the base material and is made of adhesive. Adhesive ingredients vary, with polyurethanes, acrylics, etc. Currently, the adhesive tapes for the vegetable are all industrial adhesive tapes. In the process of producing adhesives, formaldehyde is used as a raw material or auxiliary material, a bonding agent, etc. If it is not completely reacted, there may be residues. Therefore, the tape may release free formaldehyde, and it may also contain plasticizer components that are harmful to the human body. “At present, there is a regulatory blind spot for vegetable adhesive tapes. There are no relevant legal regulations and relevant standards for the production and testing of food-grade adhesive tapes.” Zhang Yuping told reporters that related laws, regulations, detection methods, and detection technologies are lagging behind. With the public's concern about the problem of tape-tied vegetables, individual regions have already called for the closure of tape-bound vegetables. Some experts advise consumers to buy vegetables tied with tape, which can be discarded in contact with the tape, and then fully soaked before cooking. Zhang Yuping said, “We appeal to relevant departments to pay attention to this issue and regulate the market for vegetable packaging. We also recommend that relevant companies take on social responsibilities. For the sake of public safety, they should use tape to tie up vegetables and they can use rubber bands or straw ropes to tie up vegetables. ."
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How to deal with vegetables containing residual glue?
Some members of the public have reported that the vegetable bandages will leave a layer of jelly and feel sticky. How to clean it?
Experts believe that detergents and other substances cannot guarantee thorough cleaning, and may also cause secondary pollution. Therefore, it is best to remove the contact adhesive tape directly, that is, cut off the part.
According to Ding Xuejia, associate professor of Materials Science and Engineering at Beijing University of Chemical Technology, supermarket sticky tapes are mostly pressure-sensitive tapes, and the main components are oily acrylics. As a pure polymer, it does not permeate into vegetables, but due to the insufficient chemical reaction in production, some small molecular oligomers are produced, including formaldehyde, toluene and other toxic substances. Ding Xuejia stated that the state has not introduced the standard for food-grade adhesive tapes, and the current testing indicators still remain at the appearance, size, initial viscosity, stickiness and other indicators, and there are no food-related testing standards. He said that from this perspective, there is no essential difference between the current use of vegetable ties and industrial tape.
According to experts, formaldehyde is a substance that destroys biological cell proteins. The World Health Organization has confirmed that formaldehyde is a teratogenic and carcinogenic substance. Exposure to low-dose formaldehyde for a long time can cause chronic respiratory diseases, gene mutations, and memory and mental decline in adolescents. In all populations, children and pregnant women are particularly sensitive to formaldehyde.
Therefore, experts suggest that it is best to use straw ropes for tying vegetables to reduce the use of substances that pollute the environment.
