Contamination of foods by inks is back in the limelight because of new worries about migration of mineral oils from packaging into food, and to a lesser extent, about the movement of nanomaterials into food from packaging.
The issue of migration received a lot of media attention around six years ago when the discovery in Italy of traces of a UV initiator – 2-isopropyl thioxanthone (ITX) – in two milk brands of Nestle, the Swiss-based multinational food conglomerate, triggered a health scare.
The printing inks sector in Europe has taken a number of voluntary initiatives over the last few years to prevent the occurrence of ink migration in food packaging.
After the IPX incident, there were calls for the European Union to draw up legislation aimed specifically at controlling inks in food packaging.
Eventually, the only legislation to be introduced was by the government of Switzerland, which is not an EU member. Dubbed the Swiss Ordinance, its regulation has since become a European standard with which packaging companies and food brand owners demand certificates of compliance from their suppliers.
However, in the midst of doubts about the effectiveness of the Swiss regulation and about the reliability of voluntary measures by industry, there are calls for legislation on ink migration preferably at the EU level, if not by national governments.
“Packaging safety remains a top priority for legislators, authorities, the packaging chain and the retail market,” Joerg-Peter Langhammer, vice president for global health, safety and the environment (HSE) at Siegwerk, told a recent conference on food contact materials in Frankfurt.
“The scenario, however, has changed,” he continued. “Voluntary commitments have lost their importance and are going to be replaced by specific packaging ink legislation based on positive list principles.
“(There is a) threat of more national regulations to come,” he added. “Packaging ink regulations would become a national rather than a European issue.”
The European Commission, the EU’s Brussels-based executive, which draws up legislation to be approved for implementation by the European Parliament and the Council of Ministers, representing EU member states, has appeared to have ruled out an EU law on food packaging inks.
“The Commission has continuously made it clear (that they do not have) the capacity for the time being to deal with a packaging ink directive nor do they consider it to be a high priority issue,” says Mr. Langhammer, who is also chairman of the technical committee on food packaging inks at the European Printing Inks Association (EuPIA).
Now individual member states are taking their own initiatives. Germany has been due this summer to issue a second draft of an ordinance on food packaging inks, modeled on the Swiss Ordinance but with much tighter restrictions. Some Scandinavian countries and Belgium are reported to be considering preparing similar legislation.
“A proliferation of different national standards would create difficulties for multinational printers and their customers,” said Felipe Mellado, Sun Chemical’s chief marketing officer. “Sun Chemical, together with other ink manufacturers and member state national authorities, supports the development of a single harmonized European regulation for food packaging inks.”
The German ministry of nutrition, agriculture and consumer safety (BMELV), which has drawn up the printing inks ordinance, claims national legislation is necessary because of the lack of regulatory action by the European Commission. It also points to evidence from German studies of unacceptable levels of migrated substances in packaged food in the country.
The ministry also argues that the Swiss Ordinance has acted as a pilot piece of legislation which provides a basis for improvements.
The draft German regulation is in fact similar to the Swiss Ordinance, with a positive list of substances which have been evaluated for their safety and non-evaluated ones which will have a content limit of 0.01 milligrams per kilo or 10 parts per billion. Toxic chemicals such as those which are carcinogenic, mutagenic or reprotoxic (CMR) will not be permitted.
The numbers of evaluated chemicals – round 900 – on the positive list will be less than those in the same category in the Swiss Ordinance. In the German regulation, they will have to meet strict criteria laid down by the EU’s European Food Safety Authority (EFSA).
A major difference with the Swiss Ordinance is a proposal that nanomaterials, even those in pigments, should be banned in food packaging inks because of the danger that they will migrate into food. “Technically manufactured nanomaterials are excluded (from the positive list) because their impact on human health are still completely unknown,” said a BMELV official.
After protests from ink manufacturers and other groups in the packaging supply chain, BMELV is now reconsidering this part of the legislation.
“The definitions on nanomaterials in the draft are very strict indeed and the resulting limitations for pigment use are equally strict, if not prohibitive,” said Mr. Langhammer. “Changes in the draft text (in this area) will be essential.”
The BMELV has been criticized for acting prematurely on nanomaterials when there is so little international agreement on how to characterize them. “There remains no single internationally recognized definition of what is construed as being a nanomaterial,” said Mr. Mellado.
Meanwhile, Switzerland’s Federal Office of Public Health (FOPH), which administers the Swiss Ordinance, has been revising its positive list. This followed claims by ink producers that substances, especially solvents, had been wrongly categorized as being non-evaluated.
There is an increasing likelihood that amid the controversy about mineral oils being found in packed food, European governments will take their own measures to resolve the issue.
This is complicated by the fact that research shows that most of the traces of mineral oil found in food have not come directly from the packaging inks. Instead, they originate from newspaper inks in recycled paper used to make paper and board packaging materials.
The German draft packaging inks ordinance, for example, bans mineral oils in inks but it does not refer to their prohibition in substrates.
This question is being left to a separate draft mineral oil ordinance which will lay down strict controls on the mineral oil content of paper and board made from recycled newsprint. For mineral oil saturated hydrocarbons (MOSH), the limit will be 0.6mg/kg, and for mineral oil with aromatic hydrocarbons (MOAH), 0.15mg/kg.
Since the 1990s, studies have been showing evidence of migration of mineral oils from paper and board packaging into foods.
In recent years, the German Federal Institute for Risk Assessment (BfR) has carried out studies on mineral oil migration. By early last year it was calling for action to reduce the amounts of mineral oils from inks from recycled packaging materials. It pointed out the dangers of short-chained saturated hydrocarbons, which are easily absorbed by the human body and can be stored in several organs.
Research published last year by a team lead by Koni Grob of the Official Food Control Authority Laboratory in Zurich, Switzerland, found that in a survey of 119 samples of dry food on the German market, migration of mineral oil had frequently exceeded safety limits by a factor of 10-100.
The high mineral oil levels seemed to be linked to the large surface areas of rice, bread and cereal contents, which enables them to absorb relatively large quantities of the oils.
Most samples were only two to three months old within a normal shelf life of one to three years. The research team estimated that migration might almost triple before the products reach the end of their shelf life.
Although some of the mineral oil may have come from recycled paper in packaging paper and board, the team reckoned that on average, about a quarter originated from the food packaging ink themselves.
Scientists in research teams like that in Zurich have shown that mineral oils go through an evaporation or “outgassing” phase when they migrate through packaging, and that this takes place in the form of chemical mixtures.
This phenomenon has highlighted the difficulty of understanding mineral oil migration because the science of chemical mixtures is relatively young and complex.
The BfR in Germany has complained about the paucity of studies on mineral oil migration, and as a result, there can be insufficient data to do proper risk assessments.
In a background report on mineral oil migration issued last year, it pointed out that there were no toxicological studies available on the effects of mixtures of MOSH and MOAH hydrocarbons. MOAH could contain carcinogenic aromatic compounds, it said.
Ink producers have stressed that mineral oils in inks should not necessarily be regarded as the major source of migration.
“There are a number of potential sources of mineral oil in food packaging, including the substrate, process lubricants, printing inks, secondary corrugated packaging and even the food itself,” said Mr. Mellado. “This is a multi-industry infrastructure issue involving the recycling, newspaper and packaging industries, and multiple options are available to resolve the current concerns, outside of ink reformulation.”
The Confederation of European Paper Industries (CEPI) is already reported to have suggested that the answer to the problem of mineral oil migration might be the reformulation of inks rather than changes in recycling processes. The ink sector will be hoping that a united multi-industry front can be maintained when a growing number of national governments start drawing up their own legislations on the issue of the migration of mineral oils and other substances in food packaging.
European Editor Sean Milmo is an Essex, UK-based writer specializing in coverage of the chemical industry.