Shoprite, SA’s biggest supermarket chain, said on Tuesday it will pay customers for reusing its newly introduced recyclable bags as it joins domestic rivals in efforts to curb plastic pollution.

Supermarkets have come under increased pressure to cut their use of plastic as images of littered oceans and beaches become commonplace, shocking consumers and shareholders. SA does not have a law banning plastic bags. However, to reduce littering and discourage customers from buying them, the government increased the plastic-bag levy in April by 50% to 12c per bag.

Shoprite said every time a customer reuses its new 100% recycled and recyclable plastic bag, which retails for R3, at Shoprite and Checkers stores, they will get 50c off their grocery purchase.

“Changing consumer behaviour by rewarding customers for reusing bags is a critical part of the retailer’s efforts to reduce plastic waste,” it said in a statement.

The retailer added that packaging of broccoli, cauliflower, baby marrows, patty pans, baby gem squash and fruit packs would switch to fully biodegradable containers from early November. Shoprite’s move comes weeks after Woolworths said it would remove single-use plastic bags from one of its stores during a six-month trial period.

Last Tuesday, supermarket chain Pick n Pay said it had removed all plastic straws from checkouts and would soon phase them out completely from cold-drink kiosks and replace them with paper straws, joining a growing number of firms that have said they will do away with disposable plastic straws.

The UN Environment Programme estimates that 8-million tons of plastic are dumped into the ocean every year — the equivalent of dumping a garbage truck full of plastic every minute — killing birds and marine life and compromising the ocean ecosystem. It wants to eliminate single-use plastic by 2022 and says more than 60 countries, including China, France, Rwanda and Italy, have taken steps to ban or reduce plastic consumption.