The Northern Ireland Retail consortium has warned that the imposition of a 5p tax on carrier bags that comes into force today risks creating “customer confusion”.

The levy charges customers for each bag they use across the retail sector, with exemptions for hot food, uncooked meat and fish, and some pharmacy items. The levy also applies to bags made from paper, plant-based material or natural starch. The charge will rise to 10p in 2014.

Environment minister Alex Attwood said he hoped to see an 80% reduction in the use of carrier bags as a result of the levy.

Northern Ireland uses around 250 million carrier bags per year.

The money raised from the levy will be paid to Northern Ireland’s Department of the Environment.

“With the legislation in place, our members have devoted substantial resources to staff training and other preparations and they’re confident they’re ready for this new regime.  Even so, there is still the possibility of frontline staff in shops, small and large, facing conflict and confusion from customers who haven’t been well enough informed,” said Aodhán Connolly, director of the Northern Ireland Retail Consortium.