An integrated sustainability assessment of drinking straws

It is estimated that eight million tons of plastic refusal including drinking straws flow to the oceans annually. A local survey revealed that 20% Malaysians use plastic straws daily. Plastic straw bans have become the new norm, and this has encouraged alternative drinking straws to compete on market. Amongst the alternatives, stainless steel straw is a popular replacement of plastic straw. However, the mining of nickel possess sustainability challenges. This leads to the dilemma to determine the more sustainable choice between plastic and stainless steel straws. This paper aims to present a comparative sustainability study of drinking straws via Life Cycle Assessment (LCA). The LCA methodology complies with the ISO 14044 standard. The system boundary of the LCA is cradle-to-gate, which covers raw material extraction and manufacturing stages. The functional unit is one drinking straw. Impact categories i.e.: abiotic resources depletion, global warming potential, acidification, eutrophication and human toxicity are studied. Next, a Sustainability Assessment Framework (SAF) is developed to evaluate these drinking straw alternatives. Analytic Hierarchy Process (AHP) is incorporated to aid decision-making on sustainability performance based on the Triple Bottom Line of sustainable development covering environment, economic and social pillars. The LCA outcome reveals that global warming potential (GWP) is the most significant impact category, and plastic straw has a lower impact value of 139 g CO2 equivalent compared to 537 g CO2 equivalent for stainless steel straw. The results of SAF shows that plastic straw has a higher priority score of 0.794 compared to 0.206 for stainless steel straw with respect to the sustainability goal. Based on both results, it is concluded that plastic straw is more sustainable than stainless steel straw.