This web page allows interactive simulations of the General Unified Threshold model of Survival (GUTS)
based on the scaled internal concentration either with a constant or a time-variable exposure concentration profile.
The two reduced (RED) versions are implemented: the stochastic death version (GUTS-RED-SD) and the individual tolerance version (GUTS-RED-IT). See [
] for details.
All calculations can be run directly within the
software by using package
; a tutorial is available
The concept of 'margin-of-safety' corresponds to the concept of 'x% Lethal Profile' or LPx as emphasized by the recent Scientific Opinion from EFSA [
Click this button each time you update a setting above
Calculations can take a long time, be patient!
Prediction of SOT
Prediction of the Survival rate Over Time (SOT)
1. Jager T, Albert C, Preuss T, Ashauer R. 2011. General Unified Threshold Model of Survival-a Toxicokinetic-Toxicodynamic Framework for Ecotoxicology. Environ. Sci. Technol. 45:2529–2540.
2. Ashauer R, Albert C, Augustine S, Cedergreen N, Charles S, Ducrot V, Focks A, Gabsi F, Gergs A, Goussen B, Jager T, Kramer NI, Nyman A-M, Poulsen V, Reichenberger S, Schäfer RB, Van den Brink PJ, Veltman K, Vogel S, Zimmer EI, Preuss TG. 2016. Modelling survival: exposure pattern, species sensitivity and uncertainty. Nat. Sci. Rep. 6:29178.
3. EFSA PPR Panel. 2018. Scientific Opinion on the state of the art of Toxicokinetic/Toxicodynamic (TKTD) effect models for regulatory
risk assessment of pesticides for aquatic organisms. EFSA Journal. 16: 5377. Available at
4. Nyman A-M, Schirmer K, Ashauer R. 2012. Toxicokinetic-toxicodynamic modelling of survival of Gammarus pulex in multiple pulse exposures to propiconazole:
model assumptions, calibration data requirements and predictive power. Ecotoxicology. 21:1828–1840.
5. Baudrot V, Veber P, Gence G, Charles S. 2018. Fit GUTS reduced models online: from theory to practice. Integrated Environmental Assessment and Management. 14:625–630.