Chemosensation plays a crucial role in the survival and ecological interactions of aquatic organisms, enabling them to detect and respond to chemical cues in their environment. This chemical communication is used by crustaceans, including amphipods, for various behaviours such as food location, predator detection, mate finding, and physiological indicators (Hardege et al., 2022). However, exposure to environmental contaminants such as polycyclic aromatic hydrocarbons (PAHs) can disrupt chemosensory processes, potentially impairing vital behaviours such as foraging and predator avoidance in amphipods (Diamond et al., 2003). Parhyale hawaiensis, a tropical marine amphipod, relies on chemosensation for various behaviours crucial to its survival (Paris et al., 2022)., making it an excellent model organism for studying the impact of contaminants on chemosensory function. This protocol aims to establish a simple and cost-effective standardised methodology for assessing chemosensory responses in P. hawaiensis using a time-to-event experimental approach, with a focus on the effects of Phenanthrene (Phe) alone and in combination with microplastics (MPs).