Food packaging materials security risks

【Chinese Packaging Network News】Food packaging materials cause safety accidents must be analyzed from the whole process of its life cycle, including raw material composition and selection, packaging container processing and printing and decorating, packaging food production, food packaging and circulation use, food packaging recycling In other areas, they constitute a systematic project.

1. Raw material composition and selection of food packaging raw materials mainly include plastics, paper, metal, glass, ceramics, etc. Among them, raw materials are rich in raw materials, low cost, excellent performance, light weight and beautiful appearance of plastic applications. The original chemical properties of plastics are stable, but there will be some monomer residues in the polymerization synthesis process, such as vinyl chloride, styrene, etc. The U.S. Food and Drug Administration has pointed out that oral intake of vinyl chloride monomer (VCM) remaining in PVC. After the possibility of carcinogenesis, it is forbidden to use PVC products as food packaging materials; at the same time, some low-molecular-weight substances will be dissolved during the polymerization process; in order to improve the processing and use properties of polymer materials, various additives must be added during the polymerization process. (Plasticizers, stabilizers, colorants, antioxidants, lubricants, etc.), and additives have some degree of toxicity in varying degrees, such as DEHA plasticizers, phthalic acid vinegar plasticizers, bisphenol A, etc.; At higher temperatures (eg, 40° C.), intense light or radiation, and at certain times, the substance will migrate from the polymer material to the food directly in contact with it, thus endangering people's health.

Pure paper is hygienic, non-toxic and harmless, and can be decomposed by microorganisms under natural conditions without causing pollution to the environment. However, when using chemical pulping and papermaking and bleaching with chlorine, paper and paperboard usually contain certain alkalis, salts, and chlorine and other chemical substances. These residues will cause food safety when dissolved in food. influences.

The glass used for food packaging is a sodium-calcium-silicon series glass in an oxide glass. The internal ions of the glass are tightly bound. After the high-temperature melting, most insoluble salts form an excellent chemical inertness, do not interact with the packaged food, and have good packaging security; however, the glass products that are not melted may occur. The problem of dissolution of toxic substances from glass raw materials. At the same time, attention should also be paid to avoid excessive levels of heavy metals such as lead in glass materials; for additive glass, attention should be paid to the safety of dissolution of heavy metal particles in colorants.

It is very important to select raw materials according to the function of food packaging. Inappropriate choices can also cause food safety problems. If poor barrier properties are selected, the shelf life of liquid milk will be shortened and even cause deterioration in a short time. For plastic wrap, if there is no adequate amount of air permeability, the freshness and spoilage of vegetables cannot be guaranteed.

2. The packaging container processing and printing and decorating metal packaging materials have high barrier properties and high and low temperature resistance. The disadvantages are poor chemical stability, acid and alkali resistance, especially when used to package high-acid foods, and the metal ions are easy to erode. Precipitation, thereby affecting food flavor. Therefore, it is generally necessary to apply paint on the inner and outer walls of the metal container. The inner wall coating is an organic coating applied on the inner wall of the metal can to prevent direct contact of the contents with the metal, to avoid electrochemical corrosion, and to increase the shelf life of the food. Layers of chemical contaminants such as BPA (bisphenol-A), BADGE (bisphenol-A diglycidyl ether), NOGE (novolac glyceryl ether) and their derivatives are also processed during canning and storage. Contamination caused by the migration of substances, through the canned food into the body, resulting in endocrine imbalance and genetic variation; outer wall coating is to prevent corrosion of the outer wall and play a role in decoration and advertising, which paint and ink containing benzene solution may also pollute food through infiltration .

Ceramic containers can maintain the flavor of foods and are used to package alcoholic beverages. The factors that influence the hygienic safety of ceramic packaging materials used in food packaging mainly refer to the use of metal salts containing toxic components such as lead, arsenic and cadmium in the glazed ceramic surface and in the glaze. When the firing quality is not good, color glaze fails to form insoluble silicate, and toxic and harmful heavy metal elements such as lead or cadmium easily dissolve out when used, dissolve into the food and cause harm to human health.

In the packaging and printing, if the ink is diluted with a harmful solvent containing benzene, n-hexane, halogenated hydrocarbons, etc., it is used as the main raw material of the ink; or when the film is compounded with an organic solvent-based adhesive containing benzene, due to the benzene during printing or processing. Incomplete volatilization of solvents may cause benzene residues in the packaging materials and infiltration into the packaged foods, which may cause food odors, or may cause cancer or blood system diseases after eating. In recent years, the qualified rate of spot inspection of plastic food packaging bags in China is generally low, only 50% to 60%, the main unqualified item is excessive benzene residues.

3. Production and distribution of packaged foods The process of packaging foods with food packaging materials is an important part of food packaging safety accidents. When plastic packaging is used, monomers, low-molecular-weight substances and various additives remaining on the polymer raw material will migrate to the packaged food at a higher temperature during the production process (or food packaging circulation and use), thereby contaminating the food. .

Metal, glass and ceramic food packaging coatings, colorants, glaze layers of heavy metal particles, will also be dissolved at a certain processing temperature, migration to food, causing safety accidents that harm human health

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Glass jars are prone to bursting bottles when they are packaged with gas drinks. There are often media reports of beer bottle blast injuries.

The sealing of paper packaging materials is difficult, and the fastness after dampness will decrease, and it will be easily broken by external forces. Therefore, special attention should be paid to avoid food packaging safety problems caused by loose seals.

4. Recycling and recycling of food packaging Currently, recycled packaging materials are mainly used in the packaging of industrial products and household detergents at home and abroad. Generally, they are not used in food packaging. This is because recycled packaging materials are used in comparison with clean packaging products. The food packaging in the production process is easy to produce low-molecular-weight substances, and will also be contaminated by harmful substances in the recycling process. Recently, however, the United States has advocated the use of recycled materials for food packaging under stringent testing conditions. As a result, the use of polymers in food packaging has emerged in the international market, such as the use of recycled polyester PET in beverage packaging bottles.

Recyclable materials for food packaging must first undergo a migration test and can be used only after passing inspection.

China Packaging Network editors believe that the safety of food packaging materials is the top priority that manufacturers must pay attention to. It is a key hidden issue that affects human life safety. How to solve and how to produce are all aspects of the packaging market that deserve attention.