The Challenge of Decontaminating Pesticide Packaging: a Critical Review of Rinsing Efficacy Using 2,4-D As a Case Study

The widespread use of pesticides has significantly increased agricultural productivity but has also created major challenges for the management of contaminated plastic packaging. High-density polyethylene (HDPE), the material most commonly used for pesticide containers, can retain pesticide residues, posing environmental and occupational risks during recycling and disposal. This narrative review critically evaluates the effectiveness of current decontamination strategies, with particular emphasis on the widely adopted triple-rinse protocol, using the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) as an illustrative case study. The review highlights how formulation properties, particularly viscosity, together with container characteristics such as size and cap geometry, substantially influence residue removal efficiency. Experimental evidence demonstrates that measurable 2,4-D residues may persist after triple rinsing, particularly in small HDPE containers and with more viscous formulations, indicating that standardized rinsing procedures do not always ensure complete decontamination. A synthesis of previous studies further confirms that rinsing efficiency varies according to pesticide formulation, container design, and operational practices. These findings emphasize the need for improved decontamination technologies, enhanced verification protocols, and container designs that facilitate cleaning, thereby supporting safer recycling practices and strengthening the circular economy for agricultural plastics.