Paperboard food packaging is more likely to leach endocrine disrupting compounds when made from recycled material rather than virgin fibres, a study has shown. The result could be significant for companies using paperboard packaging, when weighing the pros and cons of different sources.
The aim of the study, conducted by a team led by Tara Vandermarken at Vrije Universiteit Brussel (VUB) in Belgium, was to demonstrate the use of the ERE-CALUX bioassay for evaluating oestrogenic compounds in paperboard food packaging.
The ERE-CALUX 'Estrogen responsive elements, chemically activated luciferase gene expression' bioassay measures the activation of the oestrogen receptor, an important step in identifying an endocrine disruptor.
As part of the work, the scientists investigated how oestrogen activity varied depending on two factors:
- whether the paperboard contained recycled material; and
- whether the manufacturer had applied any ink on the outside of the paperboard.
They simulated the migration of chemicals from various samples and then tested the migrated compounds using the bioassay.
The results – published in Chemosphere on 4 January – indicated that the mixture of compounds from the paperboard containing recycled material was more potent. The presence of ink on the outside of the packaging, however, did not seem to influence oestrogen activity significantly.
Most likely, EDCs are introduced to the paperboard during manufacture, via, for example, adhesives and previously used inks from the recycled fibres, Dr Vandermarken says. Unfortunately, recycling does not usually remove these chemicals, meaning recycled materials are more likely to contain them.
Thus, EDCs accumulate in fibres with successive rounds of recycling. The more times a fibre has been recycled, the more potent it is likely to be.
Risk assessors could restrict themselves to specific compounds known to be EDCs and measure the levels of those compounds migrating from the paperboard, Dr Vandermarken says. In doing so, however, they would risk failing to account for unknown EDCs.
The benefit of the ERE-CALUX bioassay is that it measures directly the potency of the mixture that migrates from the paperboard, thereby addressing possible mixture effects.
A version of the bioassay is described in OECD test guideline 455.
In the EU, food packaging is covered by the framework Regulation on food contact materials (FCMs). Unlike is the case for plastic FCMs, there is no specific EU legislation for paperboard FCMs.