Recycle concern over 'green' plastics

Recyclers say biodegradable plastics like this compostable bottle could contaminate existing recycling systems.

New-generation "green" plastics are being greeted with concern in New Zealand because recycling systems are not equipped to handle them.

Last month British company Belu Natural Mineral Water launched a "compostable" water bottle derived from corn starch in one of the country's boutique grocery chains.

While there is no organic waste collection system in Britain designed to cope with the new "bio-bottle", which breaks down into compost in three months, the company hopes it will have consumers demanding more.

Plastics New Zealand environment manager Ket Bradshaw said the new plastics could be a "contaminant" in recycling systems.

"The issue for New Zealand is that we haven't got the infrastructure to pick out things like corn starch bottles and keep them separate," she said.

Most backyard composts can't break the new plastics down completely. They have to decompose at temperatures of at least 65C, usually only achieved at commercially run compost facilities.

Even waste reduction lobby groups aren't convinced the new materials are a good thing.

"There is a whole generation of biodegradable plastics on the horizon," said Zero Waste spokeswoman Jo Knight.

"Some do decompose right away, others are made of plastic with molecules in between that degrade so the plastic just falls into little bits. They are a nuisance as they get into the recycling system and cause havoc."

Called enviro-polymers, bio-plastics or polylactides, the new materials are made from plant extracts instead of the crude oil in traditional plastic or polyethylene terephthalate (PET). The idea is to collect them in a third waste stream, along with other kitchen waste, and dump them in commercial compost plants.

Waitakere City wants to introduce an organic collection but is waiting to see whether a new waste levy, under discussion between Government and industry, will be introduced to help pay for it.

Jon Roscoe, manager of Waitakere's Vertical Compost Unit, which processes organic waste, said the facility was up and running and designed for expansion but it was up to councils to make sure it happened.

"The packaging industry will adopt the cheapest and nastiest form of packaging they can lay their hands on," he said.

Ron Starnes, technology and innovation manager for New Zealand's biggest plastics manufacturer, Alto Holdings Ltd, said the company already supplied compostable sandwich packs to Milford Sound tourism company Real Journeys and cups for Auckland's annual Round the Bays run.

While rising oil prices would make plastics more expensive to produce within the next two years, no one had yet taken the first step towards a mass-produced, bio-plastic container.

"If I could find a customer who was keen to use them in reasonable numbers I could have [a product] on the market in six months," he said.

New Zealand's two big supermarket chains, Foodstuffs and Progressive, appear to be adopting a wait-and-see attitude.

"There are some inherent problems if it confused the existing recycling process," said Progressive managing director Marty Hamnet.


OUR RUBBISH

* New Zealanders throw away about 3.4 million tonnes of rubbish each year.

* Around a third of rubbish going to landfills is organic.

* Decomposition rates: paper 2.5 months, orange peel 6 months, milk carton 5 years, cigarette butt 10 to 12 years, beer can 200-500 years, styrofoam, never.