Writing in the Journal of Chromatography A Maurus Biedermann and Koni Grob said that recycled paperboard should not be used in food contact without a functional barrier but industry cannot do without it due to enormous material consumption.
Recycled paperboard essentially has unknown input so the absence of potentially harmful substances presupposes analysis of all substances potentially migrating above the regulatory threshold of 0.1 mg/kg set by the EU, they said.
“They must be a functional barrier which reduces the migration so unknown components don’t need to be evaluated,” Grob told FoodProductionDaily.com.
“A barrier reduced migration could be an internal back as a layer, it could be PET or PBOH or others as the barrier.
“The paperboard could be coated with a layer that behaves as a barrier, but it is how to form a layer that is tight and can be implemented in practice as paperboard machines would have to be modified.
"If it is coated in a thin barrier layer, so it is tight, it will protect recycling."
The work presented should provide data for the discussion whether or under which conditions recycled paper and board are acceptable for food packaging, said the researchers.
The European Food Safety Authority (EFSA) said exposure to mineral oil hydrocarbons (MOH) via packaging and some foods may pose a health hazard in an opinion in June last year.
Using Mass Spectrometry they found in 10 ppb that 300 components exceeded the limit and while they had a fairly good idea of the structure of 200 of these, they had no or limited information on 100 more, Grob added.
“Some 90 per cent are not toxic at the levels they are found but the large number makes it difficult to find which ones, it is not feasible. It makes it very difficult to find out the components of each one.”
There is presently no alternative to comprehensive chemical analysis for identification and toxicological evaluation of every substance migrating into food in relevant amounts.
The researchers said they used paperboard as an example but the problem is similar for plastic and every food grade material has to deal with the problem.
Paperboard is used for rice, breakfast cereals or breadcrumbs in carton boxes and chocolate packaging.
The researchers said there were several different kinds of recycled paper with different compositions so any list of migrating substances would have to be modified all the time due to new substances in printing inks and adhesives and processes in the recycled paper process.
Call to action
The team called for Germany to take the lead in legislation to clarify that barriers are necessary to stop the complex mix of substances migrating into food.
The study was part of a project by the German Federal Ministry of Food, Agriculture and Consumer Protection (BMELV) to obtain an overview on the substances in recycled paperboard potentially migrating in toxicologically relevant amounts into dry foods.
Grob added the EU Commission doesn’t want to regulate recycled paperboard due to lack of resources, despite the benefits of a harmonised rule for Europe.
“Germany regulators are working on mineral oil regulation but there are also a very complex mix of substances, if there is a barrier to mineral oil, it creates the impression that the problem is solved but it’s not.
“New substance components will be detected and the game will start all over again.”
Source: Journal of Chromatography A
Volume 1272, 11 January 2013, Pages 106–115, doi: 10.1016/j.chroma.2012.11.073
"Is comprehensive analysis of potentially relevant migrants from recycled paperboard into foods feasible?"
Authors: Maurus Biedermann and Koni Grob