Science - September 9, 2016

Storm in a packet of sprinkles

Rob Ramaker

Ink residues can get into our food from packaging made of recycled paper. How harmful that is, we don’t know. ‘In decades toxicologists have not managed to assess the risks.’ Meanwhile sector watchdog Foodwatch is stirring up public opinion.

Illustration: Geert-Jan Bruins

What could be more Dutch than a slice of bread with hagelslag (chocolate sprinkles)? Packets of this favourite sweet treat grace thousands of breakfast tables every morning. And some of these packets, just like packets of rice and milk, are made of recycled cardboard and paper. This means they can contain unwelcome ink residues. A discussion about the possible health risks of this pollution blew up last year and still continues.

The concern is focused on two categories of substance, known as MOSH and MOAH (see box). Both get into food packaging after the recycling of magazines and newspapers printed with ink. The substances can ‘migrate’ from the packaging into the food it contains. There are also ways such substances can end up in our food during production processes (through lubricants on machines) and transportation (through bulk packaging).

Aromatic compounds

It is a fact that MOSH and MOAH compounds are present in packaging and in our food. Food watchdog Foodwatch drew attention to this in October 2015 after studying the packaging and contents of 120 food products in the Netherlands, France and Germany. Foodwatch explicitly targeted products in which contamination was expected. MOAH were found in 43 percent of the food products, and traces of MOSH in 83 percent.

The big question is where there are health risks attached to this. ‘The tricky thing is that this is not just about one substance, but a combination,’ says Ron Hoogenboom, toxicologist at Rikilt. The name MOAH covers not just one but a vast number of compounds, all of which have a chemical ring structure. This means they are aromatic. ‘And with aromatic compounds the suspicion that they are carcinogenic soon arises,’ says Hoogenboom, ‘whereas there are plenty of aromatic substances that are not at all carcinogenic.’

‘Cause for concern’

It is not easy to make a risk assessment for these substances, confirms Ulphard Thoden van Velzen, a researcher at Wageningen Food & Biobased Research. He did a literature study for the Dutch institute for sustainable packaging KIDV. ‘In decades toxicologists have not managed to establish the risks.’ The reason for this, as Thoden van Velzen agrees, is that these compounds contain ‘tens of thousands of substances, and we don’t know what the structure of most of them looks like’. Nor did tests carried out on mixtures of substances lead to reproducible results. This is unlikely to change in the short term, thinks Thoden van Velzen. So for the time being, the assessment of the European Food Safety Authority EFSA stays the same: ‘cause for concern but no stricter norms’. Until new insights emerge.

But Foodwatch is not content to wait until new research clarifies which kinds of MOAH and MOSH are unsafe. ‘We turn it around,’ says spokesperson Sjoerd van der Wouw: the safety of substances should first be proven before they are permitted in packaging. According to Van der Wouw, this means that strict limits should be set on the permitted level of MOSH. MOAH, considered riskier, should not be allowed to end up in foodstuffs at all. In practical terms, Foodwatch would like to see food products wrapped in a functional barrier such a bag inside the box.

There are various options for preventing MOAH and MOSH from getting into our food, says Thoden van Velzen. Besides a protective inner lining, paper could be de-inked – a process which removes 20 to 50 percent of the ink – before recycling. Another process adds an absorbent substance which traps the pollutant and make it possible to remove it during the next round of recycling. An advantage of this procedure is that the unwanted substance goes out of circulation. A further possibility is for printers to use more plant-based solvents, as they do in Japan. There, says Thoden van Velzen, there are much smaller quantities of MOSH and MOAH in recycled paper.

Lip salve

Thoden van Velzen notes that the discussion about MOAH and MOSH tends to focus on the role of packaging and food products. But these may not be the main source of the traces of MOAH and MOSH that are found in our bodies. ‘You come in contact with them via lubricants, petrol stations and cosmetics and lip salve as well. We don’t know what the relative contribution is of each source.’ The choice of MOAH and MOSH as ‘molecule of the month’ seems to him rather arbitrary.

Van de Wouw at Foodwatch is not impressed by this kind of counterargument. ‘Those are the arguments the industry like to use in order not to have to take steps.’ He sees sufficient grounds and options for action in the existing knowledge. In his view, Minister Schippers of Public Health is not tackling the issue firmly enough. In her answer to questions in parliament from the Christian Union – asked in response to the Foodwatch study – she said she had raised the issue in Brussels and that public health research institute RIVM was investigating the risks. She also commented that there are no institutions in the Netherlands yet which measure the actual levels of these substances. Without that sort of information it is difficult to establish norms, said Schippers. At Rikilt, says Hoogeboom, thought is now being given to possible measurement methods.

Lidl and Jumbo

In reality Foodwatch does not need new rules to get its way. The threat of negative publicity seems to be enough to goad at least some companies into action. On 17 August Foodwatch triumphantly announced that supermarket chains Lidl and Jumbo will no longer accept any traces of MOAH in milk packaging, for example. The retailers are going to change their suppliers’ regulations in line with this. As for MOSH, a strict limit will be set. Foodwatch spokesman Van der Wouw: ‘Companies can choose whether to be frontrunners or stragglers. We shall “fame” the frontrunners and shame the stragglers.’

What are MOAH and MOSH?

MOAH (mineral oil aromatic hydrocarbons) and MOSH (mineral oil saturated hydrocarbons) are two groups of substances with long hydrocarbon chains. They are found in mineral oils and printing ink. When newspapers are recycled into food packaging they show up here as well. MOSH and MOAH are umbrella terms covering a large number of compounds. The structure of MOAH always contains a chemical ring. Scientists have identified the precise structure of only a few of these substances.