Food-safe films

Food-safe films for packaging food

What constitutes a food-safe film is regulated in Europe by Regulation (EC) No. 1935/2004. It specifies that “all materials or articles intended to come into direct or indirect contact with food must be sufficiently inert to preclude substances from being transferred to food in quantities large enough to endanger human health or to bring about an unacceptable change in the composition of the food or a deterioration in its organoleptic properties.” In addition to this regulation, further provisions define the limit values for the transfer of substances from food films to the food packaged in them. Similar regulations have been issued by the FDA (Food and Drug Administration) for the American market. Manufacturers of food films must prove through declarations of conformity that their films comply with the regulations.

Requirements for food-safe films

In addition to legal requirements, food-safe films must also meet the requirements that users and consumers have for food packaging. When used as intended, food films must not release any harmful substances into the packaged food. They must be chemically inert towards water, fat, acids and other substances that occur in the environment or in the packaged food. For consumers and food manufacturers, it is important that food films do not affect the taste or smell of the packaged product and that the appearance of the product can be inspected without visual obstruction. For good shelf life of packaged food, barrier properties against oxygen, water vapour, light and other environmental influences are important. Temperature resistance, mechanical load capacity and printability are further important properties of food films.

Food-safe films from petrochemical sources and renewable raw materials

Most of the films processed in the food industry today are made from raw materials derived from crude oil. However, there are also films made from renewable raw materials, such as the oldest food film of all – cellophane, which is made from cellulose. Here is an exemplary overview:

• Cellophane was the first food film on the market. It is made from the renewable raw material wood. In the 1950s, the material was largely displaced by lower-cost petrochemical films. The search for sustainable alternatives to petrochemical films is making the material interesting again today.
• Food-safe films based on the renewable raw materials corn starch and sugar are produced from polylactide (PLA), commonly also known as polylactic acid. PLA films such as optimont® PLA offer an alternative to petrochemical products, especially as transparent windows for food packaging.
• Polyethylene (PE), especially LDPE (low-density PE), is used to produce cling film, as used in food packaging and also in households.
• Polypropylene (PP) is heat-resistant and can therefore also be used for microwave packaging.
• Polyethylene terephthalate (PET) offers very good barrier properties, is transparent and very stable. Many variants of the film allow versatile use, from transparent windows and full film packaging through to preformed product trays.
• Polystyrene (PS) is a rigid plastic that is very well suited for yoghurt cups and similar packaging.
• Polyvinyl chloride (PVC) is approved in plasticizer-free versions for certain applications as food film.

Food films in the household

In the household sector, food films are used as cling films for wrapping and covering food. They are also used as cooking bags, for example for rice, or freezer bags for a wide variety of foods. Food-safe films are also often used today as packaging for food to take away, similar to sandwich paper or sandwich packaging. At home, but also in gastronomy, food-safe bags for sous-vide cooking under vacuum are becoming increasingly popular because they allow gentle cooking that preserves flavours very well.

Food films in gastronomy

In gastronomy, food-safe films are needed for hygienic packaging and for to-go offers or catering. Covers for menu trays or desserts that are prepared for customers but served later are also made from food-safe films. In system gastronomy, portion packs, for example for dressing, butter or jam, are also made from film containers.

Food-safe films in the food industry

There is broad demand for food-safe films in the food industry. Vacuum packaging for meat, cheese or fish is made from them. Packaging films for baked goods, fruit, vegetables or ready meals must be food-safe, as must sealing films for cups, for example for yoghurt, cream or spreads. Food-safe thermoforming films are needed for tray packaging. Shrink films are often used as transport packaging and, of course, must also be identified as food-safe films. Heat-resistant food films are required when food is pasteurized in the packaging, while cold-resistant films are needed for frozen goods.

Sustinability in food films

In order to take sustainability into account, consumers, associations and increasingly also food suppliers are calling for sustainable packaging methods. As already mentioned above, compostable bioplastics such as PLA, cellulose films or starch films made from renewable raw materials already exist. In this area, but also with petroleum-based films, increasing efforts are being made to use so-called mono-material films, which consist of only one material and can therefore be introduced more easily into recycling processes. Where possible and permitted, for example in the production of PET bottles, increasing efforts are being made to use plastics with recycled content. The aim is to establish packaging that works in the sense of a circular economy without neglecting food safety, costs, product protection and attractive product presentation.

A look into the future of food films

Despite attempts by policymakers and various market players to reduce the consumption of food films, the quantity produced continues to rise. It is difficult to balance the product requirements for food films with the desired environmental friendliness. Complex composite films that precisely meet product requirements are difficult to recycle. On the cost side, sustainable product variants still often have a negative impact. Here, it is necessary on the one hand to bring consumers along through good communication and, on the other hand, to advance research into more affordable, sustainable alternatives. The complex approval procedures for new food films are a cost driver here, which can only be offset by larger quantities of sustainable food films.

Certification features for food-safe films

Many properties must be checked for certification as a food-safe film. For many of these properties, there are separate DIN standards according to which testing must be carried out. Examples include alkali resistance, fruit acid resistance, cheese and quark resistance, lye resistance and deep-freeze resistance. In addition, the films must be heat-sealable and lightfast. The number of testing procedures alone makes it clear that certification as a food-safe film is complex and expensive.

Barrier properties of food-safe films

Barrier properties refer to the tightness of films against gases such as oxygen, vapours such as water vapour and aromas. Especially in the food sector, but also in the packaging of medicines, different barrier properties are important in order to ensure the shelf life and freshness of the product. Through special finishing of the films, the barrier properties can be adapted to the respective requirements. It must be ensured that the components used are also certified as food-safe.

Food-safe films as intelligent films

An important trend in the film industry, which also affects food-safe films, is the development of so-called active and intelligent packaging. Active films can interact specifically with the environment or with the packaged food. For example, it is possible to produce food-safe films that absorb oxygen or release antimicrobial agents. This can increase the shelf life of food without the use of additional preservatives.

Intelligent packaging can provide information about the condition of a packaged product. Colour indicators, for example, can show temperature changes or information about the freshness of the product. Automated communication with warehouse management systems can also be realized using intelligent packaging made from food-safe film.

Effects of longer supply chains on food-safe films

With the increasing importance of online food ordering and global supply chains for food as well, the challenges for food films are growing. Packaging must be suitable for longer transport times while ensuring that the packaged products arrive at retailers and end consumers in perfect condition. This requires robust materials with good barrier properties adapted to specific requirements. At the same time, food-safe films today must be as lightweight and space-saving as possible in order to reduce transport costs and CO₂ emissions. The sustainability of the films in terms of resource consumption during production and transport, as well as sustainable disposal options through composting or recycling, are also important aspects in the production of food-safe film today.

Reducing food waste through food-safe films

An important factor in the use of food-safe film is improvement in the area of food waste. High-quality packaging films with functions adapted to specific requirements, or as active or intelligent films, help extend the shelf life of food and better protect sensitive products. Studies show that selecting packaging optimally tailored to the intended use can often have a greater positive environmental impact than reducing packaging material alone. Spoiled food represents a significant environmental burden, which can be significantly reduced by selecting the optimal packaging product.

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