Most read: Countdown's 'bring your own' container ban stuns enviro-friendly customers

Making environmentally friendly choices is something Emma Shi tries to do when she is out shopping - particularly at the supermarket.

But last week she was shocked when she was not allowed to use her own container at the deli.

"The girl at the deli said, 'oh [we] have a new rule that [we're] not allowed to accept people's containers anymore because they're worried people will get sick, not from their products but from not cleaning their own containers properly'," she said.

Ms Shi said these kinds of barriers stop people from doing their bit to reduce the use of plastic.

"It's letting us become complacent to just keep doing what we always do," she said.

In a statement, Countdown said it had a responsibility to make sure all the food it sold was safe for customers.

It said while it understood and appreciated that some customers wanted to bring their own containers, that had to be balanced with its over-arching obligation to guarantee food safety.

Countdown said a container ban was currently the policy but it was a space that was evolving and changing.

But Supermarket company Foodstuffs, which owns New World, Pak'n Save and Four Square, has a trial at one of its stores allowing customers to bring their own containers for meat and seafood.

New World Howick has been carrying out the trial for the past two months.

Its owner Brendon Jones said he has had an overwhelmingly positive response.

"We've had customers saying, 'great, you're preserving the environment for future generations' but we've had other people say, 'it's great not to have our rubbish or recycle bins loaded with the plastic'," he said.

Mr Jones said there were food safety protocols that were followed when dealing with customers' containers and only containers that were clean and had a leak-proof lid were accepted.

He said expanding the BYO containers to the deli section was tricky, but they were not ruling it out.

"Service deli primarily has already cooked or ready-to-eat products, for example sliced meats and salads whereas if you look at the butchery and the seafood, 99.9 percent of those items are there to be taken home, cooked and consumed so it makes quite a difference from a food safety point of view," he said.

Two days ago, the government announced its plans to phase out single-use plastic bags by July next year.

Trevor Craig from the Bin Inn said its customers were encouraged to bring their own containers.

He said the Bin Inn stores were well on their way to getting rid of plastic bags.

The specialty grocery chain sells mainly dry wholefoods - often in bulk.

But Mr Craig said phasing out plastic for packaged meat would be difficult for other supermarkets.

"There's a lot more to that, a lot more research required and you're not going to see an answer to that anytime soon because you have to be careful of protection of food," he said.

- By Jessie Chiang