Development of a method for estimating product-specific leakage propensity and its inclusion into the life cycle management of plastic products

Abstract

The global agenda to address increasing accumulation of plastic in the marine environment is challenging key decision-makers to develop grounded responses. Current life cycle assessment approaches are unable to adequately quantify the environmental damage associated with accumulation in the natural environment, presenting a critical challenge for the life cycle management of plastic products. This paper investigates the feasibility and potential influence of using leakage rates as a proxy indicator to inform the life cycle management of plastic products. A method is proposed for the quantification of leakage rates which utilises results from beach accumulation rate surveys coupled with sales data as a proxy for waste generation. It is demonstrated for the case of Cape Town, South Africa, for selected plastic products. Through interviews with key value-chain actors in South Africa, the potential influence of providing such specific knowledge on current approaches to plastic product life cycle management is investigated. The developed leakage rates demonstrate that vastly different leakage rates exist for different types of products. In particular, plastic products associated with food consumed on-the-go were found to be highly prone to leakage. In South Africa, value-chain actors are taking a more active role in plastic pollution mitigation primarily through widespread adoption of design for recycling in packaging strategies and investment in downstream recycling activities. However, the lack of reliable information regarding plastic flows is still a constraint, resulting in a multitude of approaches for strategy development particularly when it comes to the prioritisation of products for intervention. This has the potential to result in ineffective strategies due to the inadvertent prioritisation of products which are not major contributors to marine pollution. The adoption of leakage rates as a proxy indicator for potential marine environmental impacts takes a step towards addressing a critical limitation of life cycle assessment, enabling the consideration of leakage into the marine environment during product life cycle management. Furthermore, product-specific leakage rates have the potential to provide guidance for the development of targeted strategies to address plastic pollution.