Nowadays, more and more food packaging start to use paper bags, and paper bags are the first packaging materials that meet food, and their safety is very important. Paper bags with added harmful substances can contaminate food and damage people’s bodies. So today I will introduce to you the importance of food paper bag safety and what factors will affect the safety of food paper bags.
PFASs are short for perfluorinated and polyfluorinated compounds, and their family has many members, such as perfluoro octane carboxylic acid, perfluoro octane sulfonic acid, etc. They are wear-resistant, not easily stained, and do not absorb water or oil, so they are widely used in food, chemical, textile, and other fields.
Existing toxicological studies have shown that certain doses of PFASs can cause liver toxicity, developmental and reproductive toxicity, genetic and immunotoxicity, and carcinogenicity in experimental animals. In the samples tested by a foreign environmental protection organization, PFASs were mainly detected in fried food bags (chips bags, chicken nugget bags), dessert paper bags (cookie bags), hamburger cartons, and salad paper bowls. These packagings are required to be waterproof and oil-proof, which gives PFAS the opportunity to appear. If food packaging is unqualified, it may indeed endanger health.
In daily life, we should be especially vigilant of this kind of paper packaging material. During the papermaking process, chemicals such as impermeable agents, bleaching agents, dyeing agents, etc., need to be added to the pulp, and some chemical substances may migrate into food. In addition, antifungal agents or formaldehyde used in processing may be dissolved from paper products. Do not use old newspapers, old magazines, etc. for packaging food, but special food packaging paper should be used.
To obtain the high-quality paper, in addition to paper-making chemicals, fluorescent whitening agents also play an important role in improving paper whiteness and paper quality. Pulp fibers are generally yellow or off-white because lignin in the pulp absorbs light with a wavelength of 400-500 mm. Using the method of adding dye (pigment) or using chemical bleaching, the improvement of pulp whiteness is limited.
If strong bleaching means are used in pursuit of whiteness, the strength of paper fibers will be greatly damaged. By bleaching and fluorescent whitening process, they can produce high whiteness paper. After adding a fluorescent self-enhancing agent, the paper produced, such as offset printing paper, painting newspaper, advanced writing paper, typing paper, copy paper, etc., can increase the whiteness by about 10%. It is a kind of organic compound that can improve the whiteness of fiber fabrics and paper. It is also called an optical brightener and fluorescent whitening agent.
The amount of fluorescent whitening agent that may be absorbed by human skin when it comes into contact with food packaging paper containing fluorescent whitening agent It is 0.001～0.03mg/d. The fluorescent whitening agent will not be absorbed in the animal body. The function of the whitening agent is to convert the invisible ultraviolet radiation absorbed by the product into violet-blue, fluorescent radiation, which is different from the original yellow light. The radiation complements each other and becomes white light, which improves the whiteness of the product under sunlight. Brighteners have been widely used in textiles, papermaking, washing powder, soap, rubber, plastics, pigments, and paints, etc.
Today, many food packaging paper bags are added with fluorescent whitening agents. A fluorescent whitening agent is a chemical dye that is carcinogenic and poses a potential threat to people’s health. It is not allowed to be used in food packaging according to regulations. Some manufacturers use recycled paper in whole or in part in the production process. In recycled wastepaper, there may be fluorescent whitening agents.
In addition, adding fluorescent whitening agents to the wastepaper pulp improves the whiteness of the paper, which is much lower than the cost of paper using virgin wood pulp. When using waste paper to produce paper, ink pigments can be removed by drinking, but toxic substances such as lead, bismuth, and polychlorinated biphenyls will remain in the pulp, and food will be contaminated like food wrapping paper. Some businesses may choose to use fluorescent whitening to reduce production costs. whitening the color of the paper. And the fluorescent agent in the paper bag will affect the food itself, thus endangering people’s health.
The types of inks are mainly divided into water-based inks and oil-based inks. Water-based inks are edible food inks. Water-based ink must be used when making food paper bags. Because water-based ink is used as a dissolving carrier, it is relatively safe, non-toxic, and harmless, non-flammable, and non-explosive, and almost no volatile organic gases are produced. Water-based ink is referred to as water-based ink for short, and flexographic water-based ink is also known as liquid ink. It is mainly made of water-soluble resin, organic pigment, solvent, and related additives through compound grinding.
The oil-based ink contains many heavy metals such as lead and mercury, mainly from the pigments and additives in the ink. Some aromatic hydrocarbon solvents are often used in printing inks, such as toluene, xylene, etc., which will volatilize into the air with the drying of the ink to pollute the air, and are highly toxic, cause cancer, and cause damage to the health of printing workers. The ink also contains a toxic substance called polychlorinated biphenyl, which has a chemical structure like that of DDT. If food is wrapped in newspaper, the substance will seep onto the food and then enter the body with the food. The chemical properties of PCBs are quite stable. After entering the human body, they are easily absorbed and accumulated, and it is difficult to excrete them.
If the stored number of PCBs in the human body reaches 0.5~2g, it will cause poisoning. In mild cases, the eyelids are swollen, the palms sweat, and red bumps appear all over the body, in severe cases, nausea and vomiting, abnormal liver function, muscle aches, persistent coughing, and even death. We can distinguish oil ink or water-ink from environmental protection: The main difference between water-based inks and oil-based inks is the difference in solvents. Water-based inks use water (45%~50%) as a solvent, with extremely low VOC (volatile organic compounds) content and minimal environmental pollution; oil-based inks use organic solvents (toluene, xylene, industrial alcohol, etc.) as solvent. Toluene and xylene are important items for product environmental monitoring. Compared with water-based inks, oil-based inks are less environmentally friendly than water-based inks in the process of production, use, and waste disposal.
And we also can distinguish between purpose and usability: Water-based ink is especially suitable for packaging and printing products with strict environmental protection requirements such as cigarettes, wine, food, beverages, medicines, and children’s toys. Oil-based inks are suitable for 100% cotton, cotton/polyester blends, polyester, dark and light-colored fabrics, denim, and other fabrics. Now with the “oil-to-water” environmental protection upgrade, water-based inks are gradually being used on fabrics and clothing leather. Compared with water-based inks, oil-based inks have better adhesion and firmness on some printing substrates, which need to be tested according to different products.
Oil-based inks use a water-insoluble solvent as the main component for dissolving the color base. Therefore, when making printing paper bags, the printing ink must be water-based ink. Once oil-based ink is used, it may cause serious harm to the human body.
Because of the promulgation of the plastic restriction order, more and more countries will ban the use of plastic bags and use paper bags instead. And paper bags are the most frequently used packaging bags for food, especially in fast-food restaurants such as McDonald’s and KFC. We also often see in our daily life that when you walk into a western fast-food restaurant and buy food when you get food, the food must be wrapped in a paper bag.
And now that take-out is more and more popular, businesses will also use paper bags when packing take-out. And when the plastic ban is more and more implemented, then plastic bags will be banned. Then when we go to the vegetable market to buy vegetables, we will use paper bags to pack them. And supermarket food packaging bags also use paper bags. Then, we can see that almost all food will be packaged in paper bags. Therefore, if the paper material of the paper bag is made of paper with harmful substances, then the food we want to eat may endanger our health. Therefore, the safety of paper bag paper materials is very important to us.
When choosing the paper raw materials used in paper bags, the virgin paper should be used instead of recycled paper with harmful substances added to the paper. And when making printing paper, the ink used must be water-based ink. As the first substance that meets food, food paper bags cannot contain substances that are harmful to the human body. Once they contain substances that are harmful to the human body, they will contaminate the food and harm people’s health.