Do you often use disposable cups when you are away from home? You might think this is more "hygienic," noting that some bad quality cups use fluorescent bleaches, recycled polyethylene, or they release large amounts of harmful chemicals when they pour hot water because the process materials do not pass.

Recently, the reader Wang reported to the newspaper, in order to facilitate the hospitality, she often buy disposable cups from the supermarket or people. Because of the recent cooler weather, she used paper cups filled with hot water to the guests. She found that the paper cup filled with hot water, it will emit some special weird smell. She tried several brands of paper cups, but all had such problems. Last resort, she had to put some tea leaves in the paper cup to cover up the smell.

Miss Wang is very worried: This unpleasant odor, whether prompted the material in the paper cup under the action of hot water chemical changes, the release of chemicals in the process, is not toxic? She hopes reporters can verify with the experts concerned.

With Miss Wang's question, the reporter interviewed Professor of Food Packaging Materials, South China Agricultural University, Professor Zhang Qin made.

Professor Zhang Qinfa said that paper cups in the production of water in order to achieve the effect, will be coated with polyethylene inner wall insulation film. Polyethylene is the safest chemical in food processing, it is difficult to dissolve in water, non-toxic, tasteless. However, if the selected material is not good, or the process is not relevant, the polyethylene may be oxidized to a carbonyl compound during hot melt or application to a paper cup. Carbonyl compounds are not volatile at room temperature, but can volatilize when the paper cup is poured into hot water, so people can smell it. Although there is no research to confirm whether the carbonyl compounds released from the paper cup will cause any harm to the human body and what malignant diseases can be caused. However, from a general theoretical analysis, long-term ingestion of such organic compounds must be harmful to the human body of.

Even more worrying is that some inferior paper cups using recycled polyethylene, in the rework process will produce cracking changes, resulting in many harmful compounds, in use easier to migrate to the water. The state explicitly prohibits the use of recycled polyethylene for food packaging, but because of the cheapness of recycled polyethylene, some small factories still violate the rules in order to save costs.

Professor Zhang Qinfa said that in the national standard of paper cup quality, only the microorganisms need to be tested, and no chemical substances have been detected because the tests are very complicated and difficult.

In addition to the issues just mentioned, some disposable paper cups manufacturers buy low-cost pulp, fluorescent bleach added in the production process, carcinogenic risk.

Experts said consumers in the selection of disposable paper cups, the first look should look, the packaging should not be damaged. Try to choose cup thick, stiff paper cup, the purchase can be hand squeeze gently on both sides of the cup, you can roughly know the stiffness of the cup body is good or bad. Second look at the logo, the product packaging should indicate the name of the manufacturer, address, product implementation standards, production date, period of validity. For incomplete identification of paper cups to be careful to buy. Finally look at businesses. Try to big shopping malls, supermarkets, choose large-scale production