Biodegradable plastic bags aren't the be-all-and-end-all when it comes to environmentally friendly solutions.

Countdown stores are set to phase out single-use plastic bags, with 10 stores to go plastic-bag free by the end of the month.

Plastic bags can take up to a thousand years to break down.

But Managing Director of Smart Environmental Grahame Christian says compostable bags aren't that much better.

"I don't fall for this area of compostable. I've got a lot of expertise in the refuse and recycling industry, and there's still a process and handling costs for dealing with compostable bags."

He says while Countdown's move is a great first step, people still need to change attitudes, as plastic packaging has become a matter of convenience for most people.

"It's not just about the plastic bags but if you look in your shopping bag, if you look in your refrigerator and your cupboard, almost everything is sheathed and covered in plastic. We have a massive problem, we've got to deal with it."

Graham suggests paper bags would be an ideal alternative.