Food packaging materials security risks

Chinese Packaging Network News: Food packaging materials can lead to safety incidents, and it's essential to analyze these issues throughout the entire life cycle of the materials. This includes raw material selection, manufacturing processes, printing and decoration, food packaging during production, usage in distribution, and recycling. It’s a comprehensive system that involves multiple stages and requires careful attention.

1. The composition and selection of food packaging materials mainly include plastics, paper, metal, glass, and ceramics. Among these, plastics are widely used due to their low cost, lightweight, good performance, and attractive appearance. However, the chemical properties of plastics are generally stable, but some monomers like vinyl chloride and styrene may remain after polymerization. The U.S. Food and Drug Administration (FDA) has warned that consuming residual vinyl chloride monomer (VCM) from PVC can increase cancer risk, making it unsuitable for food packaging. Additionally, during the polymerization process, low-molecular-weight substances may leach out, and various additives such as plasticizers, stabilizers, and colorants are often added to improve processing and use properties. These additives, like DEHA, phthalates, and bisphenol A, can be toxic and may migrate into food when exposed to high temperatures, light, or radiation, posing health risks.

Paper is generally considered hygienic and non-toxic, and it can be broken down by microorganisms without causing environmental pollution. However, if chlorine-based bleaching or chemical pulping is used, paper may contain residues like alkalis, salts, and chlorine, which can dissolve into food and affect its safety.

Glass used for food packaging is typically made from sodium-calcium-silica oxide glass. After high-temperature melting, most insoluble salts form a chemically inert structure, making it safe for food contact. However, if the glass isn’t fully melted, harmful substances may leach out. Also, excessive levels of heavy metals like lead should be avoided. For colored glass, the safety of pigments and their potential to release heavy metals must also be considered.

Choosing the right raw materials is crucial for food packaging. Inappropriate choices can lead to food safety issues. For example, using poor barrier materials for liquid milk can shorten its shelf life, while inadequate air permeability in plastic wraps may affect the freshness of vegetables.

2. Processing and decorating metal packaging materials have strong barrier properties and can withstand extreme temperatures. However, they have poor chemical stability, especially with acidic foods, which can cause corrosion and affect flavor. To prevent this, metal containers are usually coated on both inner and outer surfaces. The inner coating helps avoid direct contact between the food and metal, reducing electrochemical corrosion. However, these coatings may contain chemicals like BPA, BADGE, and NOGE, which can leach into food and cause endocrine disruption. The outer coating serves decorative purposes, but solvents like benzene in inks and adhesives can also contaminate food through infiltration.

Ceramic containers are often used for alcoholic beverages because they preserve flavors well. However, the glaze on ceramic products may contain toxic metals like lead, arsenic, and cadmium. If the firing process is not properly done, these metals can dissolve into the food, leading to serious health risks.

During printing and packaging, using inks diluted with harmful solvents like benzene, n-hexane, or halogenated hydrocarbons can leave residues in the packaging. These residues may seep into food, causing unpleasant odors or even long-term health effects like cancer or blood disorders. In China, only about 50% to 60% of plastic food bags pass spot inspections, with benzene residue being a major issue.

3. The production and distribution of packaged foods are critical parts of food safety. When using plastic packaging, monomers, low-molecular-weight substances, and additives may migrate into food during high-temperature processes, contaminating it. Similarly, metal, glass, and ceramic coatings may release heavy metals at certain temperatures, leading to health hazards. Glass jars used for carbonated drinks are prone to bursting, as seen in media reports of beer bottle explosions. Paper packaging may also face issues with sealing, especially when wet, making it vulnerable to damage and contamination.

4. Recycling of food packaging materials is an important area. Currently, recycled materials are mostly used for industrial products and detergents, not food packaging. This is because they can introduce low-molecular-weight substances and contaminants during the recycling process. However, the U.S. has started using recycled materials for food packaging under strict testing conditions. For instance, recycled PET is now used in beverage bottles. Recyclable materials must undergo migration tests before being approved for food use.

Chinese Packaging Network editors emphasize that the safety of food packaging materials is a top priority for manufacturers. It’s a critical issue affecting public health, and addressing it requires attention across all aspects of the packaging industry.