Design of a Reusable Shopping Bag System to Replace Single-Use Plastics in Calabar Markets

The proliferation of single-use plastic bags in Calabar markets, Cross River State, South South Nigeria, has generated mounting environmental pressure on drainage systems, waterways, and the scenic heritage of a city known for its tourism appeal. This project develops a reusable shopping bag system designed specifically for the shopping practices and logistical realities of Calabar's main markets including Watt Market and Marian Market. A user research phase involving interviews with eighty market traders and two hundred shoppers documented purchasing patterns, load requirements, and attitudinal barriers to adopting reusable alternatives. The bag system is designed in three functional variants: a large woven polypropylene tote for bulk food purchasing, a mid-sized cotton canvas bag for general shopping, and a compact fold-away nylon bag for light purchases. All variants feature reinforced handles, branded environmental messaging, and a standardised colour system to aid vendor identification. A six-week pilot distribution programme through ten market associations tested uptake, retention, and repeat use rates. Post-pilot surveys recorded a sixty-one percent reduction in plastic bag collection by participating traders and sustained reuse rates of seventy-three percent among shoppers after two months. An economic analysis confirms that the per-unit production cost of the reusable bag system is recovered after seven uses compared to single-use plastic equivalents. The project recommends a market-led subsidy scheme supported by the Cross River State Environmental Protection Agency. Keywords: reusable bags, plastic reduction, Calabar markets, environmental design, behaviour change.