The scientific study "The migration of NIAS from ethylene-vinyl acetate corks and their identification using gas chromatography mass spectrometry and liquid chromatography ion mobility quadrupole time-of-flight mass spectrometry” (Vera, P. et al. (2021)) published in the journal Food Chemistry determines that compounds present in ethylene-vinyl acetate materials, such as those found in plastic corks, can migrate from the product (the cork) to the food they come in contact with (the wine).

The migration study in question identifies a total of fifty compounds, both volatile and non-volatile, in eight ethylene-vinyl acetate wine stoppers. Of these, nine are additives such as antioxidants and cross-linking agents. Some of these compounds identified as butylated hydroxytoluene (BHT, CAS 128-37-0), is cited in Food Packaging Forum's Food Contact Chemicals database (FCCdb) as a priority hazardous substance.

Another point of study is the evaluation of the concentration at which the compounds migrate. Although the concentration of most compounds is below their SML values or the maximums recommended by the Cramer classification, it has been detected that three compounds from one of the caps migrated with an ethanol solution in the 20% at a concentration higher than the level allowed by this classification and is therefore not suitable as a food contact material.

Cork, the natural covering
Faced with the existing alternatives on the market, from the Institut Català del Suro Foundation we always recommend the use of cork, which is the only cap that contributes to the positive aging of wines. It is also a natural, recyclable and reusable product that becomes a paradigm of the circular bioeconomy.

Thanks to its negative carbon footprint, cork is also a sustainable 100% material and its use contributes to mitigating the effects of climate change.

Vera, P. et al. (2021). "The migration of NIAS from ethylene-vinyl acetate corks and their identification using gas chromatography mass spectrometry and liquid chromatography ion mobility quadrupole time-of-flight mass spectrometry." Food chemistry. DOI: 10.1016/j.foodchem.2021.130592