Assessment of the Quality of Locally Produced Polystyrene Disposable Cups in Kano Markets

Disposable polystyrene cups are ubiquitous in food service establishments across Nigerian cities, yet quality assurance for locally manufactured products is rarely documented. This study assesses the quality of polystyrene disposable cups purchased from retail markets in Kano State, North West Nigeria, comparing products from local manufacturers against imports from established brands. Samples from five local producers and three imported brands were evaluated for wall thickness uniformity, compressive strength, thermal insulation performance, and migration of styrene monomer under simulated hot beverage conditions. Wall thickness was measured at multiple points using a digital micrometre, while compressive strength was determined using a universal testing machine. Thermal insulation tests measured temperature retention in cups containing hot water at 85 degrees Celsius over a 10-minute period. Styrene monomer migration was assessed by gas chromatography-mass spectrometry following EN 13130 protocols. Results reveal significant wall thickness variability in locally produced cups, with coefficient of variation values up to 18 percent compared to less than 5 percent for imported products. Compressive strength of local products averaged 12.4 N versus 18.9 N for imports. Styrene migration levels in locally produced cups reached 0.42 mg/L under hot beverage conditions, exceeding the 0.02 mg/L limit specified in European food contact regulations. The study recommends mandatory quality inspections by the Standards Organisation of Nigeria, establishment of maximum styrene migration limits in Nigerian food packaging regulations, and technical capacity building for local manufacturers in North West Nigeria. Keywords: polystyrene cups, styrene migration, quality assessment, food contact, Kano