Charging for plastic bags has come into force in Northern Ireland as the country's environment minister pledged to dramatically cut the number used.
The five pence minimum tax per single-use carrier bag will improve the region's green credentials and help reduce pollution, Alex Attwood said.
Northern Ireland is the second part of the UK to impose the measure after Wales and follows the example of the Republic of Ireland a decade ago. Money raised will fund voluntary and community groups working on sustainability projects but small businesses have expressed concern about red tape.
Mr Attwood said: "As environment minister I want us to implement bold challenging new laws to enhance our clean and green credentials. The levy will help to do that."
People in Northern Ireland use 250 million bags a year, 140 per person. The tax will apply to all single-use bags including plastic, paper and other natural materials. There will be exemptions for takeaway hot food and drinks, prescriptions, unpackaged food and uncooked meat to protect safety and hygiene.
The Stormont minister is considering using the money to help communities and businesses improve the environment.
Possible measures include creating a river restoration fund to allow local communities to improve water quality, launching a sustainability innovation fund to support groups which want to pioneer initiatives that could generate real environmental change and produce economic and social benefits, or increasing grants from the community challenge fund to deliver local environmental efforts through not-for-profit organisations.
Mr Attwood said people in Northern Ireland used 30,000 carrier bags an hour.
"This levy is intended to help protect the environment by dramatically cutting the number of bags used," he said. "Working with the retail sector we are aiming for a reduction of at least 80%. Some retailers have already indicated that they will be eliminating single use bags altogether."
He predicted shoppers would quickly adjust to the levy. "People tell me they are concerned about climate change and want to find ways to make personal, family and local contributions to addressing the threat. The levy is precisely this," he added.