In this comment piece,  Miriam Jiménez Serrallé, a member of AIMPLAS’s Food Contact & Packaging Laboratory, explores the challenges of potential allergens in packaging made from plant- and animal based polymers.

Recently, consumers have started demanding more information about food allergens. Regulation (EC) No 1169/2011, which aims to protect the health of consumers and guarantee their right to information, requires the labelling of 14 groups of substances that cause allergies or intolerances. These substances are listed in Annex II of this Regulation.

Article 8 of the Regulation indicates that food business operators are responsible for ensuring that, both labelling and commercial documents relating to foodstuffs mention all substances, products and derived substances that may cause an allergy or food intolerance.


But should it be mandatory to declare that a material or object for food contact (FCM) contains or may contain allergens? And, if it does or may contain them, how can it be ensured they will not migrate from the packaging to the food?

Although food ingredients are not commonly used to manufacture materials for food contact, in recent years there has been a growing interest in using packaging that is more environmentally friendly, such as packaging made from plant- and animal-based polymers. In this case, the most commonly used materials include polysaccharides such as wheat starch and the proteins in milk, eggs, soya and gluten. These materials have the advantage of being biodegradable and can sometimes be produced from the by-products of the food industry. However, one of their disadvantages is that they can contain allergens and allergenic epitopes (the allergenic regions and molecules that stimulate the allergic response), especially if protein-based materials are used, which increases the risk of allergens migrating from the packaging to food. It is also necessary to bear in mind that other polymers extracted directly from biomass can be contaminated with allergenic proteins and cause an allergic reaction.

The allergenic potential of the final article depends on many factors, such as the allergenicity of the source material, the combination with other materials or the processing method. For example, there are soy-based glues and resins, and casein-based coatings. The addition of these materials to the formulation of a FCM increases the risk that the final product may contain allergenic proteins. Moreover, the physical, chemical, and enzymatic treatments carried out during production of the FCM may cause protein denaturing and/or cross-linking, which can alter protein properties. Cross-linking can reduce accessibility to epitopes, or they can be destroyed by denaturing. But some epitopes may become more exposed as a result of these treatments, thus increasing allergenicity.

Therefore, food business operators are obliged to inform consumers about the allergens the food item contains or may contain. However, FCM manufacturers are not currently required to provide customers with this information.

According to European legislation all materials intended to be used in contact with food must meet the requirements of Regulation (EC) No 1935/2004. Article 3 of this regulation states that “materials and articles […] shall be manufactured in compliance with good manufacturing practice so that, under normal or foreseeable conditions of use, they do not transfer their constituents to food in quantities which could endanger human health”. This regulation also states that “traceability […] should be ensured at all stages in order to facilitate control, the recall of defective products, consumer information and the attribution of responsibility”. However, it does not consider the chances of allergenic substances migrating from packaging to food and therefore posing a risk for consumer health.

If a FCM manufacturer detects that any of its products may contain a food allergen, the manufacturer is recommended to inform its customers and let them decide to declare the presence of the allergen on the labelling of their finished products. This recommendation is based on two considerations: no standard has been issued to set a minimum threshold below which it is not necessary to list the main allergens, and for the potential consequences which include the risk of taking the product off the market and the risk of the supplier being held liable.

It is not always necessary to declare the presence of an allergen, given that protein can be denatured during processing or protein levels may be too low. For example, highly refined oil (and ingredients derived from this oil) obtained from any of the main food allergens is exempt from labelling, since allergenic protein will not stay in such highly processed oil. This is the case of epoxidized soybean oil, which is widely used in the production of food contact materials.

In some cases, sufficient information is available on specific allergens so that companies can take their own decisions about declaring these allergens based on scientific documents confirming that the potential levels involved do not entail a risk of allergic reaction. This kind of decision generally includes the use of a significant safety margin. Any decision of this kind must be evaluated on an individual basis considering the specific use of the final product and any information available on whether the specific allergenic protein could cause an allergic reaction at the maximum exposure level.

Given the lack of regulatory guidelines on such decisions and the limited number of allergenicity studies on the materials used for food packaging, companies should act with caution in this area. Some companies disclose the presence of an allergenic protein, and also provide their own exposure analysis to help clients take a final decision on labelling.

It is important to note that the demand for bio-based materials is steadily increasing, which means that current legislation will probably change in the near future. New regulations may consider the allergenic potential of the substances used and make it mandatory for FCM producers to provide suitable information on this matter to users along the supply chain.