You are here:

Food contact materials

A/2007, 27.04.2007

Background information for journalists

When foods contain substances which consumers do not expect and certainly do not want, then public discussions can quickly become heated: plasticizers in olive oil or pesto sauces, heavy metals from ceramic glazes, printing ink components in beverages are just a few popular examples. Consumers think this is scandalous, manufacturers play things down and politicians desperately search for reliable data in order to get the situation under control as quickly as possible. After just a few weeks the whole issue blows over and very soon no-one bothers any more about the underlying reasons. And yet there is a wealth of basic information on food contact articles and materials which merits closer examination separately from individual substances, possible risks, consequences and the latest news.

Food comes into contact with specific materials for all kinds of reasons. They are mainly functional. For instance many foods already come into contact with specific machinery or cooking utensils during their manufacture or preparation. Others are transported or stored in special containers. For most of the foods on sale, the question of materials takes on importance at the very latest just before delivery to the retail trade. Many foods are well packaged to protect them from dirt or germs and to extend the shelf life of fresh produce before finding their way to the retail outlets. In some cases packaging also offers additional protection against light and air, is the bearer of information or simply  fulfils sales-promoting purposes.

The range of reasons for their use is as diverse as the number of materials which may come into contact with food. The spectrum ranges from plastics over paper, board and rubber down to naturally degradable cellulose film.

Back in 1958 "Recommendations on the health assessment of plastics and other high polymers" were issued in Germany. What the Federal Health Office (BGA) started and the Federal Institute for Consumer Health Protection and Veterinary Medicine (BgVV) continued from 1994 onwards, has been developed further by the Federal Institute for Risk Assessment (BfR). It elaborated "Recommendations within the framework of the Food and Feed Code (LFGB)" which are known as the "Plastics Recommendations". In an inventory called the "plastics database" BfR posts its recommendations on the Institute's website and makes them available to manufacturers and other interested members of the general public.

What requirements must be met by materials intended to come into contact with food?

Aluminium foil, breakfast bags, beverage cartons, filling tubes or non-stick coatings of kitchenware: these are all materials which are intended to come into contact with food. They are governed by strict statutory provisions. Regulation (EC) No 1935/2004, the so-called framework regulation, which was adopted by the European Parliament and the Council of the EU on 27 October (2004) applies to all food contact materials.

Article 3 of the Regulation sets out the "general requirements". The most important statement says: Materials and articles must be manufactured in such a way that, under normal or foreseeable conditions of use, they do not transfer their constituents to food in quantities which could endanger human health.

What happens when substances migrate from the material to the food?

Materials which come into contact with food should be designed in such a way that, if possible, no substances migrate from them to food. If this still happens then, according to Article 3 of the EU Regulation 1935/2004, the amounts which migrate to the food must be so small that they do not

  • endanger human health,
  • bring about an unacceptable change in the composition of the food or
  • lead to a deterioration in the flavour or taste (organoleptic characteristics) of the food.

The same requirements are imposed on the health assessment of substances which migrate from materials to foods as are imposed by the European Food Safety Authority (EFSA) for the assessment of applications for the inclusion of new substances in the positive list of the EU Plastics Directive. Generally speaking, the larger the amount of a substance that migrates to the food, the greater the volume of data that have to be submitted for its assessment. For instance a health assessment of minute migration amounts of up to 50 ppb can be undertaken when only basic studies concerning genotoxic effects have been carried out and submitted to the public authority.

More comprehensive toxicological studies, for instance on long-term effects, are needed for the assessment of higher concentrations of a substance in the food.

For plastics there are also substance-specific thresholds for migration to food, so-called migration thresholds. For substances for which a migration threshold could not be examined, volume limits in the material have been set instead. By way of precaution migration to a food is limited or ruled out.

How is it guaranteed that packaging materials do not constitute a health risk?

For the purposes of precautionary consumer protection from substance risks, the regulatory authorities of the federal states regularly examine foods for substances which could have migrated from food contact materials. They test them for chemicals which are of health relevance. These include for instance primary aromatic amines and formaldehyde in slotted spatulas or children's crockery made of melamine resin, plasticizers in the flexible PVC of lid sealing compounds and beverage tubes or wet strength agents in napkins and kitchen roll.

Sensory tests for changes in taste and aroma can provide initial indications of unwanted substance migration. To this end tasteless test foods, which have been simply composed but are still close to reality, are placed in contact with the material to be examined. For instance if a plastic beverage bottle is to be examined, then water is used as the test food. Chemical and chemico-physical analyses round off the sensory tests.

Furthermore, the regulatory authorities also verify the labelling of food contact articles and, by extension, the suitability of the materials for this purpose. Articles and materials which, in terms of their appearance, are not clearly designed for contact with food but are intended for this purpose like packaging films or bags must carry the wording "For food contact" according to Article 15 of the EU Framework Regulation 1935/2004. The use of symbols is also possible like those shown in Annex 2 of the Regulation: a glass and a fork.

Are extreme conditions of use also taken into account when assessing packaging materials?

Materials intended for food contact are assessed under the conditions of their least favourable, proper use. Here are a few examples: For the coatings of kitchenware possible temperature and loading conditions must be taken into account, for cling film various chemico-physical properties of the food play an important role and in the case of baby bottles the assessment of the material must also include heating with the conventional liquids in a microwave.

What tasks does BfR assume in order to guarantee the safety of food contact materials?

BfR elaborates scientific opinions on possible health risks from substances which have come from food contact materials. This is necessary, for instance, when results from the studies by the regulatory authorities mean a review is necessary or an up-to-date, unbiased and neutral assessment is called for in a public debate. In these cases the health risks are examined on the basis of toxicity data on the substances in question and an estimation of possible consumer intake. Specific groups like infants may also be given special attention. If necessary the assessment procedure may not only encompass the impurities themselves but also look at metabolites which may be formed through conversion in the human metabolism or in food.

Furthermore, BfR prepares the so-called "Plastics Recommendations". To this end the Institute has a regularly updated database which can be accessed on the BfR website. The BfR recommendations always take account of the latest scientific findings and technological developments. Although they are not legal standards, they do offer important accepted guidance when it comes to establishing whether a food contact material or article fulfils the statutory requirements pursuant to Article 3 of the EU Regulation 1935/2004. Furthermore, BfR staff are members of expert panels of the European Food Safety Authority (EFSA) responsible for assessing food contact substances on the EU level.

Do food contact materials need a special authorisation?

There is no specific authorisation procedure for food contact materials. As already outlined above, the requirements of the EU Regulation 1935/2004 must be met by all materials and their components if they are to be used in contact with food. Manufacturers are responsible for this. Furthermore, there are other specific provisions laid down in the Commodities Ordinance which are relevant for specific substances, for instance a positive list of starting materials (monomers) and a substance list for additives used to manufacture plastics. Applications may be submitted for the inclusion of monomers and additives in the corresponding lists. Prior to their inclusion in these lists the substances must be examined for possible migration to food and their toxicological properties must also be evaluated. One result of these tests is the laying down of thresholds for the migration of substances to food or their content in the materials.

This means that for the substances contained in the lists toxicological data are available which considerably facilitate the assessment of the health risk in the event of migration to food. However, the lists are restricted to plastics and cellulose film. Cellulose film is in fact better known under the brand name cellophane; it is a transparent packaging film made of regenerated cellulose which is used for instance for sweets, cheese or sausage.

Which application areas should be improved in the interests of precautionary consumer protection?

BfR believes there is an urgent need for provisions on the EU level for the many substances which come into contact with food through the print on food packaging. More than 1,000 substances are used for the printing of food packages. For most of these chemicals there are no or only limited findings on possible health effects. In the event that substances of this kind migrate from packaging to food, it is not possible to undertake a reliable risk assessment. The migration may constitute a problem for health although this is not necessarily the case.

The discussion about the printing ink chemical, ITX, in beverages has shown that this demand has not been triggered by hypothetical scenarios. However, the public debate did largely ignore the fundamental aspect of a previously unregulated group of substances. This legal loophole must be closed for all substances with this intended use. The use of alternative substances about which we know even less in some cases when it comes to their toxicological properties is not a viable alternative from the assessment angle.

Constant bone of contention: Why are plasticizers still permitted as components of packaging materials?

Plasticizers ensure that plastics are pliable and flexible. This makes them interesting as packaging materials and essential depending on the use. The term plasticizer encompasses very different chemicals which fulfil the same technical functions. In terms of the substances involved, not every plasticizer is the same. There are also toxicological differences between the substances, in some cases major ones. This means that given the wide number of substances used as plasticizers, any risk assessment must focus on a specific substance. As some chemicals are used widely, the assessment must take into account, if possible, all input paths and contact opportunities.

When it comes to the question as to why plasticizers are still being used in packaging materials, two fundamental aspects must be borne in mind: packaging materials provide effective protection for food against dirt, germs and other harmful elements. In some locations, for instance in screw top seals, it is the use of these plasticizers that guarantees these protective properties. Their use can, therefore, make sense. On the other hand, when harmful substances could migrate to the food, they should be replaced with less critical plasticizers. One example here is the phthalate, DEHP, which is thought to be reprotoxic.

The use of critical plasticizers in terms of health should always be challenged when they could impose a burden on consumers. That is why the EU has introduced some bans. In the EU some phthalates, which also include the above-mentioned diethyl hexyl phthalate (DEHP), may no longer be used in cosmetics. On the European level a ban was also handed down on the use of problematic plasticizers in baby toys (for children aged 0 to 3 years). As of 16 January 2007 DEPH, di-n-butyl phthalate and butyl benyl phthalate may no longer be used in concentrations above 0.1% in toys and baby articles. This is tantamount to a ban on their use as plasticizers. From that date onwards other plasticizers may no longer be used in concentrations of more than 0.1% in toys or baby articles which children put in their mouths.

Independently of the foods, these bans cover important intake paths and this plays a role when it comes to the overall assessment of possible contacts and intake levels. Another hoped for effect is the development of less problematic plasticizer substances.

As of 30 March 2007 an EU Directive (2007/19/EC) limits the migration of phthalates to foods.

Outlook

Risk assessment is already looking at the growing number of consumer products with antimicrobial surface materials. Coatings of this kind have been extensively examined for use in medical devices and are available on the market. However, for most consumer products like fridges and washing machines there are no reliable data on efficacy or on substance migration under real conditions of use. Frequently these coatings do not offer any additional hygiene benefits for consumers. Quite the contrary: consumers could mistakenly think they are safe and neglect standard hygiene measures in the home.

Active and intelligent packaging materials are another area which could become more important in future. In the case of active materials, certain substances are intentionally transferred to the food. Only authorised food additives may be used for active packaging like preservatives in order to protect the surface of a heated and germ-free food through contact with a correspondingly treated film. Furthermore, consumers may not be misled by active packaging materials about the actual condition of the food. This could for instance happen if dyes are released which create the misleading impression that the food has been smoked.

Intelligent packagings are materials which indicate for instance to consumers or retailers whether the cooling chain has been interrupted or whether the sell-by date has been exceeded. This is, in principle, a useful food safety application.

More extensive information

Responses to frequently asked questions on packaging materials and a wealth of information on this topic are available on the BfR website www.bfr.bund.de/cd/template/index_en under "Commodities", "Materials in contact with foods".

Up