Mechanistic modelling approaches, as the toxicokinetic-toxicodynamic (TKTD) framework, are promoted by international institutions as EFSA and OECD to assess the environmental risk of chemical products generated by human activities. TKTD models can encompass a large set of mechanisms describing the kinetics of compounds inside organisms (e.g. uptake and elimination) and their effect at the level of individuals (e.g. damage accrual, recovery and death mechanism). Compared to classical dose-response models, TKTD approaches have many advantages as taking into account temporal aspects of exposure and toxicity, considering data-points all along the experiment and not only at the end, and making predictions for untested situations as realistic exposure scenarios. Among TKTD models, the General Unified Threshold model of Survival (GUTS) is within the most recent and innovative framework but is still under-used in practice, especially by risk assessors, because specialist programming and statistical skills are necessary to run it. Making easier the use of GUTS models through a new module freely available from the web-platform MOSAIC (standing for MOdeling and StAtistical tools for ecotoxIClogy) should promote GUTS operability in support of the daily work of environmental risk assessors. This paper aims at presenting the main features of MOSAIC_GUTS (MOSAIC-GUTS 2018): uploading of the experimental data, GUTS fitting analysis and LCx estimates with their uncertainty. These features will be exemplified from literature data.
Toxicokinetics-toxicodynamics, Survival, Web interface, Bayesian inference, LCx estimates