Packaging News

Materials: Crunch time for food packs

Low-migration inks have been around for years. But it wasn’t until two big migration scares shook the industry that converters really started to sit up and pay attention to the issue. First, in 2007, Tetra Pak and Nestlé were forced to recall baby milk packaging because traces of Isopropylthioxanthone (ITX) were found to have migrated to the product. It was later discovered that this had probably happened when the freshly printed material was rolled ready for converting, thus transferring traces of ITX onto the other side of the board.

There are two EU regulations to which food suppliers must conform in respect to packaging. Food Contact Framework Regulation (EC) No 1935/2004 includes a reference that materials used in packaging should not transfer their constituents to the food in any harmful way; while the Good Manufacturing Practices Regulation (EC) No 2023/2006 has been applicable since 2008 and determines minimum requirements for good manufacturing practices. Using low-migration inks could be one way to fulfil these good manufacturing processes.

Ink manufacturer Stehlin Hostag has made bold leaps into the world of low-migration inks. The company offers a range of high-performance conventional sheetfed and UV process inks and a full range of GMP-manufactured spot colours, water-based coatings and UV varnishes (see box).

Increased awareness
Stehlin Hostag’s UK business manager for packaging inks Jim Buchanan says: "At the moment, low migration accounts for 15-20% of our packaging inks and this is expected to increase as there is more understanding and awareness and legislation becomes more enforceable."

According to Buchanan, companies are showing considerable interest in low-migration inks at the moment, but commercial pressures are an issue. King’s Lynn-based carton converter CPC took the bold step of dedicating a specific press to low migration inks (see box), supplied by Stehlin Hostag, so as to avoid potential cross contamination with other inks.

However, dedicating a press to low-migration inks is a costly affair and is not a practical solution for smaller printers who have smaller jobs, more changeovers and may not be able to afford the more expensive inks. Even some larger printers are hesitant to dedicate their resources fully to the technology.

Carton converter Benson Group has not yet experienced great enough demand for low-migration inks to warrant assigning a press to their use. "We are certainly aware of the issues, and have conducted trials with a number of low-migration inks," says managing director Mark Kerridge. "We are in a position to offer low-migration inks to customers if that is their need."

Kerridge says customers are currently seeking more information. The group participates in UK and European action groups to ensure they are fully aware of the latest information on this topic. "We are certainly happy to say to customers that we have conducted trials and we are in a position to offer a clear understanding of the options and the alternatives," adds Kerridge.

Carton-converting giant Chesapeake, meanwhile, has already dipped its toe into the world of low-migration. The company has a number of litho and flexo presses across its European sites that use the inks.

"Some of Chesapeake’s larger customers are spearheading a clear strategy to ensure consumer safety remains paramount," says Chesapeake’s marketing manager Bob Houghton. "It is expected that the use of low-migration inks will become more prevalent for certain applications and may be used in other market sectors, such as health foods and healthcare, in the future.

"The greater use of these inks is expected to offer additional benefits such as reducing the incidence of taint and odour problems, which can also affect food-related products."

The 4MPB incident was a prime example of problems arising from poor communications. In this case, the food producers failed to communicate to the carton converters the nature of the plastic used.

Informing the industry
Sun Chemical’s Stephenson is keen to emphasise that all aspects of the supply chain must be engaged to ensure migration is avoided. "You have to have joined-up communication and thinking so that everybody is designing that packaging for the end purpose intended."

"The ink maker can recommend an ink for a specific substrate and press, but has no knowledge, usually, of the foodstuff to be packed or the pack design so it lies with the pack designers and printer converters to determine what is or isn’t an appropriate ink or coating for the packaging application, low migration or not," says Stephenson.

What is clear is that more explanation is required to define the converter’s obligations in this area. Chesapeake’s Houghton says: "At the moment, the term low migration is not specifically defined and further legislation is needed to establish a European standard, specific to fibre-based materials, which can be used by the entire supply chain."

BPIF Cartons is fully aware of the concerns regarding migration. The body has responded by creating a technical team to work with all the parties in the supply chain in the UK and mainland Europe. Out of this work has come the creation of a draft Good Manufacturing Practice document, which is currently under review by the Food and Drink Federation (FDF) and Food Standards Agency (FSA).

BPIF Cartons general manager Neil Whipp explains that the project has come out of converters’ lack of resources to carry out testing and their customers’ lack of time. The organisation has therefore moved to research what generic tests can be established that will enable both converters and food manufacturers to be comfortable that they are following the new GMP guidelines – and therefore fulfilling their responsibilities.

Recorded incidents of migration have heightened converters’ awareness of low-migration inks. But while they can help avoid such incidents, they are still expensive and require a dedicateed press. And it is not solely a converting issue meaning brands will likely take the leading role.