KEY POINTS:
The triangular-arrows symbol on plastic containers that suggests they are recyclable is misleading, says Recyclers of New Zealand (Ronz).
The national recycling body says that in many cases such containers are not recyclable.
Executive director Bruce Gledhill said using a symbol that was widely accepted as having a meaning or affiliation when no such link existed was misleading.
"Our growing concern is about the use and design of labels and logos that may imply or do suggest recyclability where no such prospect exists in New Zealand."
Mr Gledhill said that the international plastics industry, in particular, had integrated the universally recognised triangular recycling symbol with a centrally-placed number - one to seven - representing the industry resin-code numbering system.
The Society of Plastics Industries symbol did not represent recyclability, he said.
The SPI codes one to six were specific as to their base resin, and code seven meant the material could be anything else or combinations of any number of the resins.
"Confusion reigns, especially when manufacturers add other plastic and non-plastic materials to the base resin to give the finished material certain performances."
Mr Gledhill said Ronz had tried to convince brand owners of the need to validate their claims for New Zealand.
"Ronz advocates for the labelling laws to incorporate mandatory use of a series of recycling symbols that are appropriate and validated in the New Zealand context."
Mr Gledhill said they should be appropriate in an age of increasing automation of recycling collections and recyclables processing, and valid in provincial locations where mechanisation might never be adopted.
"Manufacturers and retailers should verify that their product can actually be recycled before using such claims."
Ronz had suggested providing more information with the arrow symbols.
An E could be used to show the material was suitable as an energy source, an M for those suitable for recovery of their material value, and an X for products that should not enter the recycling stream because of hazard risks.
"These three symbols would quickly require no interpretation and would eliminate the pressure at local government level to grapple with commodity markets when specifying their schedule of nominated recyclables. The onus for this would be passed back to brand owners."
Paul Curtis, executive director of the Packaging Council of New Zealand, agreed the resin codes on plastic packaging "fell short of what was desirable". He said the problem was exacerbated by the differing recycling practices of local councils.
In Auckland and Christchurch the councils collected codes one to seven plastics, but in Wellington only codes one and two were collected.
That meant a countrywide code would not be practical, he said.
Mr Curtis said the key was for councils to collaborate to collect greater volumes of plastic types for which markets could be found.
"Hopefully then there's a better chance of collecting plastics one to seven right across the country."
Rick Poynter, a New Zealand agent for overseas granular plastic producers, said the codes were "far from perfect" and that was even acknowledged in the United States, from where the system had been picked up.
"But until something superior is developed it is better than nothing."
He did not believe, however, that in practice serious problems occurred in plastic collections around the country. He thought the revised system suggested by Ronz had merit and he would be happy to see it used on New Zealand products.