The New Zealand plastics industry today backed the use of polycarbonate in packaging, saying consumers had been unnecessarily alarmed by the results of a United States study.
Plastics New Zealand environmental affairs manager Carolyn Cox said polycarbonate was "totally safe" in its common applications, even when long-term food contact was involved.
She
said polycarbonate was employed extensively for a wide range of applications, including compact discs, protective equipment, and food and drink containers.
The grades used for food contact had been specifically and scientifically approved by authorities such as the US Food and Drug Administration (FDA).
"The FDA is known to have some of the most stringent regulations in force," Ms Cox said.
"All New Zealand manufacturers of polycarbonate food and beverage products comply with these."
Last month, researchers in Ohio reported that exposure to the ingredient bisphenol A (BPA) caused birth defects in mice.
BPA is a building block (monomer) that is transformed through polymerisation to make polycarbonate.
The study was based on the findings of Patricia Hunt and colleagues from Case Western Reserve University.
Dr Neville Miller, a polymer technology specialist with the New Zealand government science company Industrial Research Ltd, expressed reservations about how the study had been reported.
He said some media reports had been speculative about the findings and about BPA's safety for human health.
There was a lack of information about the stringent testing required for polycarbonate food handling products, he said.
There was also a lack of detail about the level of the BPA the mice were exposed to.
Dr Miller took issue with a statement by Missouri University toxins expert Fred von Saal that BPA was one of the most commonly used plastic materials in food and drink containers.
Dr Miller says BPA was not a plastic material in its own right, but was an intermediate used in the production of polycarbonate.
He said the great majority of plastic consumer products in New Zealand and overseas were made from polyethylene, polypropylene, PVC, polystyrene and PET -- none of which contained BPA.
Meanwhile, New Zealand polymer chemist Dr Peter Plimmer said polycarbonate has been used for drinking water containers for years without any reports of any toxicity from extracted BPA.
He said manufacturers had to test potential toxic effects in order to meet FDA and European safety criteria for food handling safety.
- NZPA
