Northern Ireland has introduced a compulsory charge on the sale of all plastic shopping bags in a bid to stop litter and improve environmental health.
The minimum tax of 5p per single-use carrier is expected to improve the green credentials in the region, besides reducing pollution.
The Republic of Ireland introduced a plastic bags tax 11 years ago, when it was estimated that about 1.3bn plastic bags were given by shops annually.
That figure was reduced by 90% within three months.
Environment minister Alex Attwood said people in Northern Ireland use some 250 million carrier bags annually, which approximates to around 140 per person a year.
"This levy is intended to help protect the environment by dramatically cutting the number of bags used," Attwood said.
The tax will be applicable to all single use bags, including plastic, paper and other natural materials, excluding takeaway food and drinks, prescriptions, unpackaged food and uncooked meat.
The ministry is also working with the retail sector on plans to reduce the number of bags used by at least 80%, and some retailers have discussed the elimination of single-use bags altogether.
WSP director David Symons, commenting on the plastic bag tax, said, "This decision has been made with the right sentiment and will make an impact on waste levels, but according to our calculations it will only shave around 10kg CO2 off each person's carbon footprint."
Engineering and design consultancy in the UK, WSP provides integrated management and consultancy services to all aspects of the built and natural environment.
Image: The plastic bag tax will improve the green credentials in Northern Ireland; Photo: Courtesy of winnond.