The production and consumption of plastic products had been steadily increasing over the years, leading to more plastic waste entering the environment. Plastic pollution is ubiquitous and comes in many types and forms. To enhance or modify their properties, chemical additives are added to plastic items during manufacturing. The presence and leakage of these additives, from managed and mismanaged plastic waste, into the environment are of growing concern. In this study, we gauged, via an online questionnaire, expert knowledge on the use, characteristics, monitoring and risks of plastic additives to the marine environment. We analysed the survey results against actual data to identify and prioritise risks and gaps. Participants also highlighted key factors for future consideration, including gaining a deeper understanding of the use and types of plastic additives, how they leach throughout the entire lifecycle, their toxicity, and the safety of alternative options. More extensive chemical regulation and an evaluation of the essentiality of their use should also be considered. •The environmental presence and leakage of plastic additives are of growing concern•This survey gauges experts` knowledge on the use, characteristics, monitoring and risks of plastic additives•The results demonstrated a lack of knowledge on production, use, sources, pathways, analytical methods and ecotoxicity•Collaboration among scientists, industry, and stakeholders is vital for a safe and sustainable transition to additive use•The experts recognise the importance of regulation and legislation in mitigation