Adhesives in the dock for causing reproductive failures

New research into the potential reprotoxic impact of chemicals migrating from multilayer plastics has thrown the spotlight on adhesives, guidance on ‘non-intentionally added substances’ (NIAS), and the synergistic effects of compounds originating in packaging materials.

The debate about the risks from packaging as a source of endocrine disruptors goes back decades. But earlier this summer, a team from Zaragoza University, Spain, published a paper claiming to offer the first in vivo demonstration of reprotoxicity from direct contact between plastics packaging and in this case pig sperm.

‘Really significant’

Lead author and director or Zaragoza’s GUIA research group Cristina Nerin said the findings were “really significant”. The study appeared in the May issue of Scientific Reports, sister publication to Nature magazine, and focused on reproductive failures in artificial insemination in Spanish pig farms during 2010, which had been traced back to the plastic pouches used to store the pig spermatozoa.

“The reprotoxicity from direct contact between the spermatozoa and the substances migrating from plastics bags had never been shown before,” said Nerin. The team traced this effect back to cyclic lactone and the bisphenol A (BPA) derivative Badge, both originating in the polyurethane adhesive used to bond layers within the laminate.

“The synergistic effect for reprotoxicity has been demonstrated through in vivo studies,” she said. “We have found the same compounds in some laminates used for food packaging around Europe.”

Wider implications

At Germany’s Fraunhofer Institute, head of product safety and analytics Roland Franz was less convinced about the study’s wider implications. “The reason for the observed infertility is not clear, and to make the measured chemicals responsible for the case is highly speculative. Most likely, the plastic bag has indeed played a role, but what role precisely is not yet clear.”

Nerin concluded: “We need better guidance on testing for NIAS from packaging, as well as better controls on adhesives themselves.”