Hygiene and Safety Requirements for Liquid Food Packaging Sound a Warning Bell for the Liquid Packaging Industry

With the advancement of industrialization and the improvement of residents' living standards, milk and beverages are increasingly finding their way into households, and the paper-plastic packaging materials that come with them are reaching ever deeper into people's lives. As such packaging brings convenience to people's lives, how to guarantee people's health has made the hygiene requirements for milk and beverage packaging materials increasingly important.

At present, there are mainly three forms of dairy and beverage packaging on the market: one is paper-plastic composite packaging, the second is plastic film packaging (three-layer film, five-layer film), and the third is plastic bottle packaging (high-density polyethylene HDPE, polyester PET). The following discussion focuses mainly on paper-plastic composite packaging materials, for everyone's reference.

With the progress of society, the continuous rise in awareness of food safety and environmental protection, and the constant advancement of technology, developed countries have put forward higher requirements in this regard, and our country also has new plans for sustainable social development. At present the state has relevant standard requirements for paper-plastic composite packaging materials, while hygiene requirements are regulated by reference to the requirements for food packaging base paper and food-grade polyethylene.

To ensure that liquid packaging materials meet packaging hygiene requirements and reach an advanced level, the raw materials used to process the packaging materials must first reach the corresponding hygiene standards. The paper-plastic composite materials used for dairy packaging mainly involve four raw materials, and the main functions of each are as follows: 1. Paperboard mainly provides the strength and stiffness of the package. 2. Polyethylene mainly blocks liquid contents and microorganisms. 3. Aluminium foil mainly blocks oxygen, light and odours. 4. Ink is mainly used for printing to reproduce the patterns required by customers. Food hygiene and safety impose very strict requirements on raw materials in order to ensure the taste, nutrition and freshness of food. The following introduces the three main raw materials of paper-plastic composite packaging materials: paperboard, ink and polyethylene.

1. Base paper for packaging. As the main raw material of packaging materials, paper, although not in direct contact with liquid foods, is subject to relatively strict hygiene and safety requirements when used as base paper for food packaging. Domestic requirements for base paper are mainly based on the Measures for the Administration of Domestic Food Packaging Base Paper promulgated in 1990, which require that the base paper used comply with GB11680 Hygiene Standard for Food Packaging Base Paper, for example with respect to fluorescent agents, colouring agents and heavy metals. European and American countries now require certification against the relevant FDA provisions, imposing corresponding requirements not only on the finished base paper (for example, microorganisms, contaminants and odour), but also corresponding requirements and certification on the raw materials, processing equipment and environment used to process the base paper, so as to ensure that the base paper processing conforms to food packaging requirements. There are especially corresponding special requirements for milk packaging paper, such as the strength and moisture content of the board and the prevention of secondary invasion by bacteria or microorganisms.
2. Printing ink. Because the heavy metals and solvents in ink migrate both inwards and outwards, there is a major safety hazard if they enter the packaged contents. Most countries now advocate the use of environmentally friendly inks, alcohol-soluble inks and water-based inks, and water-based inks in particular are being increasingly promoted and used as green, environmentally friendly inks. However, in some traditional printing operations many manufacturers still use solvent-based inks, especially toluene or xylene as the solvent for printing. In China there are still no clear regulations on this to date, and many production and processing manufacturers are not subject to the management and supervision they deserve. In developed countries in Europe and America, however, it is expressly stipulated that benzene-based solvents are prohibited in food packaging, and the use of toluene or xylene, if it penetrates the skin and enters the human body, can endanger haematopoietic function and the nervous system. The requirements for inks, especially for solvent-based inks, are mainly discussed from the following aspects.

The first is heavy metal content. There are no relevant domestic standard requirements for the heavy metal content of ink; at present the standards for testing heavy metal content mainly comprise the arsenic and lead content specified in GB11680-89, the hygiene standard for base paper for food packaging. The EU safety standards EN71-3:1993 and EN71-7:1997 and the US ASTM F963-96a all set strict standards and regulations for the heavy metal content of ink. Cadmium, lead, chromium and arsenic pose serious hazards to the human body; prolonged exposure and continuous accumulation in the body can cause a decline in immune function and lead to retarded intellectual development in infants and young children.

The second is the residual amount of volatile organic compounds (VOC), which mainly refers to the residual amount of organic solvents from solvent-based inks in packaging materials. Current standards for testing VOC content can refer to China's industry standard Gravure Composite Plastic Film Ink (QB/T2024-1994), which stipulates that the sum of the residual amounts of eight solvents including toluene, xylene, ethyl acetate and acetone shall not exceed 30 mg/m2. The inks used for dairy packaging printing are mainly solvent-based inks and water-based inks. Of particular note here is the use of water-based inks: because their solvent is water, they have no impact on the environment and are good for human health, and they should be the main development direction for liquid packaging.

However, because of their relatively high cost and the relatively high printability requirements in printing, most enterprises still use solvent-based printing inks.

1. Polyethylene for packaging. In China there is the Hygiene Standard for Polyethylene Resin for Food Packaging (GB9691-1998), which sets corresponding requirements for other organic substances, heavy metals, dyes and other impurities in polyethylene.

On the premise that raw materials are assured, control of the production process is also very important. The outer packaging of raw materials shall meet hygiene requirements, such as the transport requirements for raw materials, the storage of raw materials, the requirements for the warehouse, and the standards for placing raw materials. Next we also need factory buildings suitable for processing food packaging materials, requirements for air-conditioning temperature and humidity in the processing workshop, and air purification, pressure and airtightness in the workshop, so as to ensure a good processing environment; however, this requires relatively high investment and operating costs, so many domestic enterprises have not given it sufficient attention in plant construction and production.

The health requirements for operators and correct codes of conduct for food processing operations are also important elements of hygiene and safety. Control measures for packaging material quality must also be established, and high-performance equipment provided to meet food packaging requirements and ensure good operation. Avoiding the entry of foreign matter as far as possible, as well as online monitoring, recording, sorting and rejection of quality, are also all very important. Factories shall obtain the corresponding ISO9000 and ISO14000 certifications and ensure the effective operation of the ISO systems, guarantee the hygiene and safety of product quality, and effectively prevent substandard products from entering the market.

In short, to guarantee the safety and hygiene requirements of liquid packaging, high-standard raw materials, a good processing site, good processing machinery and equipment, employees with a good awareness of food hygiene and safety, and a good production and processing process are all needed to ensure the hygiene and safety quality of packaging materials.

Therefore, in the face of fierce market competition, many enterprises, in order to reduce production costs, have not adopted corresponding hygiene and safety measures, seeking only their own benefit at the cost of serious damage to the environment and to people's health. At the same time, the industry lacks corresponding sound hygiene and safety access requirements, supervision and control are lacking, and safety and hygiene are neglected. We should therefore publicize this vigorously, give consumers the right to know, and strengthen supervision to drive the improvement of product hygiene quality.

——This article is reprinted from China Packaging Network (pack.cn), original link: http://news.pack.cn/show-362286.html