Is it safe to store food and prepared meals in plastic containers?
Plastic bottles, containers and dishes have firmly entered our everyday life. But simultaneously with “plasticization”, there are more and more reports about the danger that this material is fraught with: under certain conditions, it releases toxic compounds that, when they enter the human body, gradually undermine his he alth
American scientists claim that up to 80% of the "plastic" substances found in the human body get there from building and finishing materials, in particular, from such popular plastic windows, furniture, but most of all - from dishes: from food-grade plastic all kinds of compounds pass into food. Domestic manufacturers, in turn, assure that certified plastic utensils are absolutely safe. True, they make a reservation: if you use it for its intended purpose.
The most common polymer materials (or plastics) are polyvinyl chloride (PVC), polypropylene, polyethylene, polystyrene and polycarbonate. They produce both technical and food plastics. The polymers themselves are inert, non-toxic and do not "migrate" into food. But here are intermediate substances, processing aids, solvents, as well as chemical decomposition products that can penetrate into food and have a toxic effect on humans. This process can occur during storage of products or when they are heated. In addition, polymeric materials are subject to change (aging), as a result of which degradation products are released from them. Moreover, different types of plastic become toxic under different conditions - some cannot be heated, others cannot be washed, etc.
Dangerous fragility of plastic
Polyvinyl chloride is a chlorine-based polymer. It is distributed all over the world because it is extremely cheap. It is used to make bottles for drinks, boxes for cosmetics, containers for household chemicals, disposable tableware. Over time, PVC begins to release a harmful substance - vinyl chloride. Naturally, from the bottle it gets into soda, from the plate - into food, and from there - directly into the human body. And vinyl chloride is a carcinogen. A PVC bottle begins to release this dangerous substance a week after the contents have been poured into it. A month later, several milligrams of vinyl chloride accumulate in mineral water. From the point of view of oncologists, this is a lot.
Often plastic bottles are reused, they are poured into tea or fruit drinks and even alcoholic beverages. Markets sell milk and butter in plastic bottles. Five-liter bottles have replaced buckets and canisters for summer residents, and advocates of a he althy lifestyle go with them to springs for “living” water and store Epiphany water in them for a year. Experts are unanimous: nothing but water can be refilled into water bottles. And even then not in all. Only PET bottles can be reused (see table). PVC bottles release toxic PVC. However, many experts are sure that any bottled plastic remains neutral only in the absence of oxygen, that is, as long as the water retains its original chemical composition. As soon as the bottle is opened, the water quickly changes its properties, after which the plastic inevitably changes its properties. As for "living" and holy water, its healing properties can only be preserved in glass containers.
How to distinguish hazardous PVC products from safe plastic? You need to look at the bottom. Conscientious manufacturers put an icon at the bottom of dangerous bottles - a three in a triangle. Or they write PVC - this is how PVC is designated in English. But there are few such bottles with honest inscriptions. Harmful capacity can also be recognized by the influx on the bottom. It happens in the form of a line or a spear with two ends. But the surest way is to press the bottle with your fingernail. If the container is dangerous, a whitish scar forms on it. The "correct" bottle stays smooth.
Comfortable, practical, but risky
It's time for picnics, and in order to minimize domestic inconvenience, we stock up on plastic plates. Pour tea from a thermos or alcoholic drinks into plastic cups. Cheap, practical, but not safe. Disposable plastic utensils cost a penny. But plastic is a delicate material. Cracks in the world. Melts from the heat. For strength, stabilizers are added to it. Plastic is getting stronger and… more toxic.
Polystyrene (indicated by the letters PS) is indifferent to cold liquids. But as soon as you pour a hot or alcoholic drink, a harmless glass begins to release a toxic compound called styrene. Plates made of polystyrene are often used in summer cafes for barbecue. And the client, in addition to hot meat and ketchup, also receives a dose of toxins. Polypropylene glass (marking - PP) withstands temperatures up to +100°C. But it does not tolerate a chemical attack - it emits formaldehyde or phenol. If you drink vodka from such a glass, not only the kidneys suffer, but also the eyesight. Formaldehyde is also considered a carcinogen.
Disposable packaging - one time only
In order for plastic utensils to be safe, they must be used strictly for their intended purpose. Food plastic of different brands has different properties. One brand of this polymer raw material is intended for the production of water bottles, the other is for bottles with carbonated drinks. Yogurt cups are made from a grade of plastic that allows injection molding to be lightweight and cheap, yet neutral to milk fat, while pudding cups should be resistant to sugar.
Therefore, experts insist: in no case should plastic packaging be used as food storage containers, and disposable tableware should not be used repeatedly. How plastic will react to contact with ingredients for which it was not intended, what compounds can be formed in this case, no one has investigated. Especially insidious are fats and acids, which can draw free toxic compounds out of plastic.
There is another important point. The plastic container must be washed before reuse. The disposable packaging was not intended for washing, so the result is unpredictable. The release of all kinds of compounds from plastic is greatly enhanced by heating. Therefore, only special containers can be used in the microwave oven.
Mayonnaise, ketchup and other sauces, seasonings, juices, jams, as well as ready-made soups and cereals that require heating, are sold in packages - regular or "standing". Such bags are made from multilayer combined films. The choice of film depends on the properties of the product, the period and conditions of its storage. Soups, cereals, main courses are packed in bags of films with a high melting point. Dishes in such packaging can be heated in the microwave or boiled directly in the bag. But physiologists advise eating them less often: the less chemistry in life, the better. When purchasing instant products (those that only need to be poured with boiling water), pay attention to the packaging (cup, bag, plate). Although Rospotrebnadzor and certification bodies monitor the safety of materials, nevertheless, manufacturers often use polystyrene packaging. And when it comes into contact with hot water, it begins to release harmful monomers - styrenes. Therefore, it is better to transfer products to ceramic or enameled dishes and then pour boiling water over them.
Frozen ready meals in trays that can be reheated in the microwave or oven are made from crystallized polyethylene terphthalate. Its properties remain unchanged in the range from -40° to +250°C. True, some brands may lose the necessary heat resistance after being subjected to deep cooling.
Little doses big problems
How to determine acceptable and safe doses of chemicals? The opinions of scientists differ. Some argue: if you do not exceed the permissible level, there will be no harm. You need to eat more than 2 kg of canned food per day to get closer to the maximum allowable dose. Others insist that the more chemicals a person consumes, the more it destroys the body. If there are no symptoms of poisoning, this does not mean that the substance is safe. Toxins can accumulate over the years, undermining he alth. Even small amounts are poisonous if exposed for a long time. Plastic entered our lives only 30 years ago. Now the first truly “plastic” generation is growing, while to draw conclusions about the effect of plastic on the body, you need to observe at least five generations…
The Mystery of the Tin Can
Any polymeric material ages under the influence of light, heat, heating and contact with all kinds of substances. Then it becomes cloudy, absorbs odors and ingredients from the contents and releases toxic substances. Food manufacturers indicate that the shelf life applies not only to the product itself, but also to the packaging. This is especially true for canned goods. For example, they can detect a toxic substance - biphenol. Plastic film containing biphenol is lined on the inside of cans so that the metal does not come into contact with food. From here, biphenol can pass into the content.
• Ditch canned food for fresh and frozen food.
• Transfer food from opened cans to glass, even if it is a short-term storage (under the influence of oxygen, the corrosion of cans increases dramatically and the content of lead and tin in food begins to increase rapidly).
Nadezhda Tarakanova, technologist at Bytplast
Plastic used for the production of products in contact with food and children's assortment is subject to mandatory examination for compliance with sanitary and hygienic standards and is certified. And if the manufacturer claims, for example, that the product is intended for drinking water, then it is checked as a container for drinking water.
The manufacturer is obliged to label his products. Food plastic has a generally accepted label - "glass and fork". It may say that it is intended for cold, bulk or hot products, for use in a microwave oven or for freezing, sometimes a temperature range is indicated. “Snowflakes” indicate that the container is suitable for freezing food, “wave oven” indicates that the dishes can be heated in the microwave, and “shower plates” indicate that the containers can be washed in the dishwasher. This marking is also used by some Russian manufacturers, including us.
Watch the markings
At one time, to simplify the sorting of plastic, a special international marking was developed - triangles formed by arrows with a number inside. The number indicates the type of plastic. Instead of a number or under a triangle at the same time as the number, you can find the letter code of the plastic:
PET Polyethylene phthalate: bottles for carbonated drinks, water, juice, dairy products, vegetable oils, cosmetics, etc.
HDP High density polyethylene: bagging bags, trash bags
PVC Polyvinyl chloride: building and finishing materials, furniture, shoes, medical products, water bottles, food packaging film
LDP LDPE: detergent bottles, toys, pipes
PP Polypropylene: medical products, utensils for hot meals, food packaging film
PS Polystyrene: disposable tableware, dairy, yogurt cups, electrical insulation film Other plastics: multi-layer packaging or composite plastics