Food contamination by food containers, packaging materials, and food tools and equipment and its pre

作者：admin  点击次数：22  发布时间：2025-04-21

Food containers and packaging materials refer to paper, bamboo, wood, metal, porcelain, ceramics, plastics, rubber, natural fibers, chemical fibers, glass and other products used to package and hold food, as well as coatings that come into contact with food. Food tools and equipment refer to machinery, pipes, conveyor belts, containers, utensils, tableware, etc. that come into contact with food during the production and operation process. With the development of the chemical industry and the food industry, there are more and more new packaging materials. Food containers, packaging materials and food tools and equipment come into contact with food through processing, transportation, packaging, and holding, and harmful substances in them may migrate to food. (I) Hygiene of plastics
Plastics are polymer compounds formed by the polymerization of a large number of small molecular monomers through covalent bonds. They are made of polymer resin as the main raw material, with an appropriate amount of additives added, and plasticized under certain conditions.
1. Types of plastics
According to the changes in performance after heating, they can be divided into two categories: thermoplastics and thermosetting plastics. At present, the thermoplastic plastics allowed to be used in food containers and packaging materials in my country include polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), vinylidene chloride-vinyl chloride copolymer resins (VDC/VC), polycarbonate (PC), polyethylene terephthalate (PET), polyamide (PA), acrylonitrile butadiene styrene (ABS), acrylonitrile syrene (AS), etc. Thermosetting plastics allowed to be used in food containers and packaging materials include melamine-formaldehyde (MF) resin.
2. Plastic hygiene issues
(1) Plastics have poor barrier properties, which increases the chance of food being contaminated by microorganisms; disposable plastic containers, packaging materials, and long-term backlog products that have not been strictly disinfected often exceed the standard for microbiological indicators; plastic products are not easy to degrade in the natural environment and are prone to "white pollution"; impurities and pollutants attached to plastics are not easy to wash off, and the sources of recycled products are complex. The "Regulations on the Hygiene Management of Plastic Products and Raw Materials for Food" stipulates that recycled materials shall not be used to process food containers, packaging materials, and tableware.
(2) Some low-molecular compounds contained in plastics, including free monomers that have not participated in polymerization, low-polymerization degree compounds that are not fully polymerized, and low-molecular decomposition products, may have certain toxic effects on the human body. (3) Some additives added to plastics can migrate into food and may be toxic to the human body. Additives used in plastics include plasticizers, stabilizers, lubricants, colorants, antioxidants, UV inhibitors, antistatic agents, fillers, etc. Some plasticizers may have toxic effects. For example, some phthalates have the characteristics of estrogen and the biological effect of anti-androgenic hormones. They can increase the stillbirth rate of rats, and the offspring will appear tailless, legless, bent hind legs, skull deformity, and can cause symptoms such as multiple neuritis, sensory insensitivity, numbness, etc., and have inhibitory and anesthetic effects on the central nervous system; di-2-ethylhexyl adipate [di-2-(ethylhexyl)adipate, DEHA] has carcinogenic effects on animals. The General Administration of Quality Supervision, Inspection and Quarantine issued an announcement on October 25, 2005, prohibiting the distribution of cling film containing DEHA or PVC monomer content exceeding the standard, and prohibiting the use of PVC cling film to directly package meat, cooked food and oily food. Stabilizers such as lead barium stearate and cadmium are more harmful to the human body, so they cannot be added as stabilizers to plastic containers, packaging materials, tools and utensils. When polyvinyl chloride products come into contact with solvents such as ethanol and ether, they will promote the dissolution of lead. (4) Harmful substances exist in printing inks and adhesives. The ink contains heavy metals such as lead, cadmium, mercury, and tantalum. The "Sanitary Standards for the Use of Additives for Food Containers and Packaging Materials" only allow the use of solvents such as ethanol, butanol, acetone, and ethyl acetate, but some manufacturers use xylene, isopropanol, butanone, etc. to dilute the ink. Toluene originally exists in benzene-containing inks and is also used as a solvent for diluting inks by some manufacturers. Adhesives contain toluenediamine. These harmful substances can migrate into food.