Hong Kong is swamped in trash -- with 13 dumpsites filled to the brim, and the final three landfills set to run out of capacity by 2030.

The city's legislature passed a bill last month to implement a two-stage blanket ban on various plastic products.

The idea is "to build a plastic-free culture", authorities said, but environmentalists are worried that the ban's benefits could be undermined as the city would merely be replacing plastic waste with those other materials if the city continues with its "throwaway culture".

Campaigners have called for a lifestyle change to reuse.

Unlike her fellow Hong Kong urbanites toting plastic or paper cups filled with coffee, pet groomer Lucine Mo takes her caffeine hit in a thermal mug with a QR code.

The coded mug can be returned to 35 coffee shops taking part in a Greenpeace pilot project aiming to change one of the city's most wasteful consumption habits -- the near-instinctive use of disposable cutlery.

"Since I learned about the service, I have stopped using those plastic and paper cups," Mo told AFP.

"If a restaurant provides reusable cutlery (for takeaway), I am totally fine with it."

That practice is nearly non-existent in Hong Kong, but come Earth Day on April 22, 2024, caterers and consumers will see a ban on disposable plastic cutlery take effect in more than 28,000 eateries.

"The problem actually lies in the throwaway culture," said Greenpeace campaigner Leanne Tam.

"We must tackle the root cause and think about how to replace disposable products with reusable ones."