The determination of environmental hazard thresholds and the characterization of their impacts represent fundamental pillars in the realm of environmental science and risk assessment. As human activities continue to exert unprecedented pressures on natural ecosystems, there is an increasing imperative to comprehend the thresholds beyond which environmental stressors pose significant risks to biodiversity, ecosystem functioning, and human health. This necessitates a multidisciplinary approach that integrates insights from ecology, toxicology, epidemiology, and environmental chemistry to delineate the intricate interactions between pollutants and biological systems. Moreover, understanding the thresholds underlying the toxicity of environmental contaminants, including that caused by complex materials such as HARNs and MCNMs, is essential for determining their effects across different biological organisms and ecosystems. Toxicity identification provides invaluable insights into the underlying mechanisms of toxicity and enables the extrapolation of findings from model organisms to broader ecological contexts. By elucidating these thresholds, there is a possibility of better mitigate the adverse impacts of environmental contaminants, thereby safeguarding both environmental integrity and human well-being. In this context, this report endeavours to provide a comprehensive overview of the determination of environmental hazard thresholds and their characterization, through the development of toxicodynamics studies. A brief introduction of the models applied in the experiments are described.