For paper and board food packaging only little regulation and legislation exists, and the composition of the packaging is in many cases unknown for the consumer and the authorities. A PhD project at the National Food Institute, Technical University of Denmark, shows that paper and board food packaging contain well-known and new endocrine active chemicals.
Food packaging constitutes a potential source of chemical contamination of food products, and in this way humans may be exposed to these chemicals. Bisphenol A is used in such plastic packaging as cans and plastic bottles but is also present in some paper and board packaging made from recycled paper. Fluorinated substances are used for surface treatment of paper and board packaging.
The endocrine disruptive potential of bisphenol A is well known, and behavioral changes as well as changes in the development of breast tissue have been found in animals exposed to this compound in even low quantities at the foetal stage. Fluorinated substances only slowly degrade in both humans and the environment and are linked to harmful effects on the human immune system, amongst others.
A lack of data on bisphenol alternatives and fluorinated compounds
As bisphenol A is prohibited for certain uses in the European Union, the substance is increasingly being replaced by structurally similar compounds, so-called bisphenol A analogues. However, data about the potentially harmful effects of analogues is lacking. At the same time, new alternatives to fluorinated substances have been introduced to the market, for which we have no data about their potentially harmful effects.
The lack of data is a concern in the efforts to ensure food safety and ultimately human health. In her PhD project at the National Food Institute, Anna Kjerstine Rosenmai examined whether five bisphenol A analogues potentially have similar effects as those of bisphenol A, and whether 19 fluorinated substances have a potential for endocrine disruption.
Potential substitutes are not safe alternatives
Cell-based tests of the five bisphenol A analogues bisphenol B, E, F, S and 4-cumylphenol showed that, in general, they have the potential of being endocrine disrupting such as bisphenol A itself. This indicates that bisphenol A analogues are not safe alternatives to bisphenol A.
Studies of the 19 fluorinated substances showed endocrine activity as well, however, in a more varied way and with less significant effects. Some fluorinated substances showed estrogenic effects, whereas others showed antiandrogenic effects by reducing the synthesis of the male sex hormone testosterone.
“My studies show that you should be cautious in replacing known problematic compounds by compounds for which toxicological data are lacking or insufficient. Now we know that bisphenol A analogues and fluorinated substances have the potential to cause adverse health effects in humans,” PhD student Anna Kjerstine Rosenmai says.
Test strategy identifies new chemicals in food packaging
Furthermore, a test strategy to identify problematic compounds in paper and board food packaging was developed. The strategy consists of a step-by-step procedure, in which advanced analytical chemistry tools as well as a broad battery of cell-based tests are used.
By applying this strategy five chemicals with endocrine disruption potential were successfully identified in two types of food packaging: a pizza box and a sandwich wrapper. The identified compounds were, amongst others, bisphenol A and two phthalates, which are known to be active in animal tests. In addition, a couple of completely new chemicals were identified.
”Many packaging types are used which contain chemicals that have either not been tested at all or for which no publicly available data exist. Through this project we have obtained new knowledge about chemicals in food packaging, and developed a test strategy which can be used when evaluating new paper and board packaging,” Anna Kjerstine Rosenmai explains.