Alex Ashton is the co-host of Newsroom's daily podcast, The Detail.

Podcast: The Detail

Three plastic bag-free weeks - how are we doing?

Three weeks after single use plastic bags were officially banned, The Detail looks at how businesses and customers alike are coping. Retail NZ says it's been a smooth transition, but a hazardous materials expert says we could be making things worse.

New Zealand has now joined dozens of other countries in banning single-use plastic bags.

But supermarkets have told The Detail they're selling more plastic bags such as pet waste bags and bin liners as a result - and compostable bags are flying out their doors.

The Ministry for the Environment is currently investigating 130 complaints over businesses breaking the law, even though the country's had months to get used to the idea.

The big supermarket chains had already ditched the type of bags you might have had stuffed in a kitchen drawer, and Countdown ran down the stocks of its 15c ‘emergency bags’ leading up to the official ban on July 1.

Now, shoppers have the choice of paper, polypropylene ‘eco’ bags, or fabric. Pockets and hands also provide an option for the forgetful among us as we get used to the new plastic-free reality.

Retail NZ’s chief executive Greg Harford says the transition has gone smoothly.

“Customers have got used to the idea, and the feedback is that most retailers have complied with the requirements and are no longer issuing plastic bags.”

Most, but not all, according to the Ministry for the Environment – which has received 130 complaints about alleged breaches of the ban since July 1.

“We are assessing the information provided to date, to verify its accuracy. Where necessary we will be contacting businesses reported to be supplying banned plastic bags.

“The Ministry is taking an education-first approach, and part of that is reaching out to businesses that are alleged to be non-compliant, so we can learn why they haven’t yet made the transition to comply with the ban.”

But as countries around the world continue to ban plastic bags, some academics worry it might not be as effective as it seems.

Trevor Thornton, a hazardous materials lecturer at Deakin University in Melbourne, is concerned that a ban might make things worse.

He says more targeted research is needed to make sure a ban is the best solution.

“Overall, I think it’s a bit of an overreaction in terms of what are the issues we should be looking at.”

Thornton points to research looking at plastic bag bans in California, which showed the sale of single-use plastics - like bin liners - jumping following bans.

These products, he says, can be more harmful than the banned plastic bags because they are thicker and often dyed.

“If we’re looking at resources, then we’re going the opposite way.”

Thornton says he would have held off on a widespread ban.

“I would’ve said, OK, there’s a bit of an issue, let’s see how many people are using them and how many times they use them, and then do the sums to find out what the alternatives are and whether they’re better or worse for the environment.”

While the ban is still in early days and there hasn’t been a lot of time to collect data. Foodstuffs - which owns Pak ‘n Save and New World - confirmed it is seeing increased sales of plastic bags since they stopped giving them away.

“Naturally there’s been a bit of an increase in all bin liner sales since we removed SUP bags from checkout on 1 January 2019,” says Foodstuffs NZ’s Head of External Relations, Antoinette Laird.

“This increase includes plastic bin liners, but also new-to-market innovations including home compostable bin liners which our shoppers are taking to like moths to a flame.

“Pams recently launched a line of home compostable bin liners, which are made from corn starch and will break down over time. Lining rubbish bins with newspapers doesn’t work for everyone, so it’s critical we provide shoppers with options that best fit their needs and help them adapt to the change.”

Countdown says its sales data is commercially sensitive so wouldn’t say if more people were buying plastic products.

But general manager of sustainability, Kiri Hannifin, says 90 percent of customers now bring their own bags or don’t use one - with the rest opting for paper or buying reusable ones.

Want more from The Detail? Find past episodes here.