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Materials in Contact with Foods

A/2013, 03.07.2013

Background paper for journalists

If foods contain substances which we as consumers do not expect or desire to find there, public discussion flares up quickly: plasticisers in olive oil and pesto, heavy metals from ceramic glazes and printing ink ingredients in beverages are only a few examples. Consumers find it scandalous, manufacturers look for the causes and politicians search for reliable data to get the situation under control as quickly as possible. After a few weeks, the excitement has died down and soon no one even bothers about what went on in the background. There is, however, a lot of basic information on objects and materials that come into contact with foods which it is worth taking a closer look at irrespective of individual substances, possible risks, consequences and the latest news.

Foods come in contact with certain materials for many different reasons, most of which have to do with functionality. Accordingly, many foods make contact with special machines or cooking utensils during their manufacture or processing, while others are transported or stored in special containers. For a very large percentage of the foods on offer, the material question becomes important at the latest shortly before delivery to retailers. As protection against dirt and germs – and to prolong the shelf life of fresh products – many foods are well packed before they find their way onto the shelf. The packaging also protects the contents from light and air in some cases, conveys information or serves promotional purposes.

As different as the uses can be, as different the materials that come into contact with foods can also be. The spectrum ranges from plastics through paper, cardboard and rubber to biodegradable films made of cellophane.

“Recommendations for the Health Assessment of Plastics and other High Polymers” have been issued in Germany since as far back as 1958. What the Federal Health Office began and the Federal Institute for Consumer Health Protection and Veterinary Medicine (BgVV) took over in 1994 is now being continued by the Federal Institute for Risk Assessment (BfR). It has prepared “Recommendations Within the Scope of the Food and Feed Code (LFGB)”, which can be found in the database “BfR Recommendations on Food Contact Materials (formerly Plastics Recommendations)”. In this database, the BfR makes its recommendations available to manufacturers and the general public on the institute’s homepage.

Which requirements do materials which are to come into contact with foods have to satisfy?

Aluminium foil, sandwich bags, beverage cartons, filling hoses and the non-stick coatings of cooking utensils – these are all materials intended to come into contact with foods and they are subject to strict legal regulations. Regulation (EC) No. 1935/2004, the so-called Framework Regulation, which was adopted by the European Parliament and EU Council on 27 October (2004), applies to all materials that come into contact with food.

Article 3 of the regulation lists the “General requirements”. The most important stipulation it contains states that materials and objects must be manufactured in such a way that under normal and foreseeable conditions, their physical components are only transferred to foods in quantities which do not endanger the health of the consumer.

What happens if substances from the material are transferred to foods?

Materials that come into contact with foods should be designed in such a way that to the extent possible, no substances are transferred from them to the food. If this happens nevertheless, Article 3 of EU Regulation 1935/2004 stipulates that the quantities transferred to the foods must be so low that

• human health is not endangered,
• they do not result in an unacceptable change to the composition of the food and that
• they do not impair the aroma or taste of the food.

The same demands are placed on the health assessment of substances which transfer from materials to foods as the European Food Safety Authority (EFSA) uses as the basis to evaluate applications for the inclusion of new substances in the positive list of Regulation (EU) 10/2011 on plastic materials and articles intended to come into contact with food. The general rule is: the more of a substance is transferred to food, the greater the quantity of data that has to be presented for an assessment. This means that a health assessment for only very small transfer quantities of up to 50 ppb can be made if only basic tests for mutagenic effects were conducted and presented to the authorities. On the other hand, more extensive toxicological tests on such aspects as long-term effects are required for the assessment of higher concentrations of a substance in food.

In addition to this, there are substance-specific limit values – so-called migration limits – for the transfer from plastics to food. Alternatively, quantitative restrictions in the material apply to substances for which migration limits cannot be verified. In this way, transfer to foods is limited or excluded as a precaution.

How is it guaranteed that packaging materials do not pose any health risks?

The monitoring authorities of the federal states examine foods regularly for substances which could transfer to the food from contact materials. The tests are made for chemicals which are relevant to health, such as primary aromatic amines and formaldehyde in spatulas, or kitchen dishes made of melamine resin, plasticisers in the soft PVC of lid sealants and beverage hoses or wet strength agents in napkins and kitchen rolls.

First indications of undesired substance transfers can be given by the sensory tests for changes in taste and smell. To do so, test foods with a neutral taste and the simplest possible composition are brought into contact with the material under examination. If, for example, a plastic beverage bottle is to be examined, water is used as the test food. Chemical and chemical-physical analyses support the sensory tests.

In addition to this, the monitoring authorities check the correct labelling of objects with food contact and thereby the suitability of the materials for the intended purpose. Objects intended for contact with food but which do not clearly appear to be, such as packaging films or bags, must bear the note “For food contact” in accordance with  Article 15 of EU Regulation 1935/2004. The use of symbols, such as the glass and fork symbol shown in the annex to the regulation, is also possible.

Are extreme application conditions taken into account when assessing packaging materials?

Materials intended for contact with foods must be assessed under the worst possible conditions of their intended purpose. Here are a few examples: the possible temperature and load conditions have to be taken into account with the coatings of cooking utensils, the various chemical-physical properties of the food play a specially important role with food packagings and the assessment of the material used for baby bottles must also include the heating in a microwave oven.

What does the BfR do to guarantee the safety of materials that come into contact with foods?

The BfR prepares scientific opinions on the possible health risk of substances from materials with food contact. This becomes necessary, for example, when the results of the tests conducted by the surveillance authorities require reassessment or an updated, neutral and objective estimation is demanded in a public discussion. In cases of this kind, health risks are assessed on the basis of data on the toxicity of the substances in question and an estimation of the possible intake by consumers. Special consideration can also be given to certain population groups, such as small children. If necessary, the assessment process can relate not only to the contaminants themselves but can also take metabolites into account, resulting from transformation in the human metabolism or in the food.

The BfR also prepares recommendations on materials for food contact. To this end, the institute maintains a database which is freely accessible via the BfR homepage and which is updated regularly. The recommendations of the BfR reflect the latest level of available scientific and technical knowledge in each instance. This means that even though they do not constitute mandatory standards, they are an important and well-accepted guide to establish whether or not an object with food contact satisfies the legal provisions of Article 3 of EU Regulation 1935/2004. In addition to this, BfR staff also serve as members of specialised committees of the European Food Safety Authority (EFSA) where substances with food contact are assessed on a European level.

Do materials intended to come into contact with foods require special approval?

There is no special authorisation procedure for materials with food contact, but all materials and their components have to comply with the aforementioned provisions of EU Regulation 1935/2004 if they are intended to come into contact with food. The manufacturers have the responsibility here. Regulation (EU) No. 10/2011, a direct and mandatory European regulation, came into effect in 2011. It contains a legally binding positive list of the monomers and additives which may be used for the manufacture of synthetic materials and objects which are intended to come into contact with food. Before being included in this list, the substances have to be tested for their possible transfer to foods and their toxicological properties. As one of the results of the test, limits are established for the transfer of the substances to food. In this way, toxicological data are available for the listed substances, which makes an assessment of the health risk in the event of a transfer to food considerably easier. The lists are limited to plastics and regenerated cellulose, however. Regenerated cellulose is a transparent packaging film made of regenerated cellulose better known by the name Cellophane which is used for packaging sweets, cheese or cold cuts.

Which areas of application should be further improved?

More than 1000 substances are used for the printing of food packagings. Very little knowledge of the possible health effects, if any at all, is available for the majority of the chemicals. In the event that substances of this kind are transferred from the packaging to the food, no meaningful risk assessment is possible, so the transfer can pose health problems. The public debate about the printing ink chemical ITX in beverages, however, has disregarded to a great extent the fundamental aspect of a substance group that has been unregulated up to now. Substitution by other substances about which even less is known regarding their toxicological properties cannot be a solution from the point of view of risk assessment.

Why are plasticisers still allowed as components of packaging materials?

Plasticisers are what make plastics malleable and flexible. This also makes them interesting as packaging materials, and sometimes even indispensable, depending on their use. Various chemicals intended to fulfil the same material functions are combined under the heading “Plasticisers”. From a purely material point of view, there are differences in the plasticisers, and there are also some distinct toxicological differences between the substances. Where risk assessment of the large number of substances used as plasticisers is concerned, this means that a test specific to each individual substance must always be made. In view of the widespread use of some substances, the assessment must then take into account all sources for exposure to the greatest possible extent.

Regarding the question as to why plasticisers are used at all in packaging materials, two fundamental aspects should be considered: packaging materials provide effective protection of foods against dirt, germs and other damaging effects. At some points, such as gaskets in screw caps, only the use of plasticisers can guarantee these protective properties, so it can make sense to use them. On the other hand though, if substances harmful to health can transfer to the food, they should be replaced with less critical plasticisers. Accordingly, the phthalates DEHP and DBP, which are classified as toxic to reproduction, may not be used as plasticisers in food packagings in accordance with Regulation (EU) 10/2011.

Questions should always be raised about the use of plasticisers which are critical to health if this can negatively affect consumers, which is why the EU has imposed several bans. This has had the result that several phthalates, including the aforementioned bis(2-ethylhexyl) phthalate (DEHP), may no longer be used in cosmetic products in the EU. With toys too, a ban was imposed on a European level on the use of potentially health-damaging plasticisers in baby articles (for children aged 0 to 3 years). Since 16 January 2007, DEHP, di-n-butyl phthalate and butyl benzyl phthalate may no longer be used in toys and baby articles in concentrations greater than 0.1 %. From this date too, other plasticisers may not be used either in concentrations greater than 0.1 % in toys and baby articles which children can put in their mouths.

With these bans, significant entry paths have been closed irrespective of any specific food, a fact which plays a role in the overall assessment of possible intakes. Another desired effect is the development of plasticiser substances which are less problematical.

Outlook

Risk assessment has been dealing for quite some time now with the growing number of consumer products with antimicrobial surface coatings. Whereas coatings of this kind have already been thoroughly examined and marketed for use in medicinal products, no reliable information on effectiveness and substance transfer under real application conditions is available for the majority of consumer products, such as refrigerators and washing machines. No additional hygienic effects for the consumer are to be expected in many cases either. On the contrary, they could be lulled into a false sense of security and neglect the customary measures of household hygiene.

Another area which could gain in significance in future is so-called active and intelligent packaging materials. With the active materials, certain substances are deliberately transferred to the food. Only authorised food additives may be used for packagings, which actively release substances such as preservatives to protect the surface of a heated and germ-free food through covering with an appropriately treated film. Neither should it be possible to mislead consumers through active packaging materials by disguise of the actual condition of the food, as would be the case if colorants were transferred which give the impression that the food has been smoked.

Intelligent packagings are understood to be materials which indicate to the consumer or dealer whether the cold chain has been interrupted or the sell-by date is exceeded, aspects which in principle make good sense where food safety is concerned.

Additional information

On its homepage www.bfr.bund.de, the BfR provides answers to topical and frequently asked questions concerning packaging materials along with lots of other information in the column “Product Safety” under the heading “Food contact materials”.

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