This web page allows interactive simulations of the General Unified Threshold model for Survival (GUTS) based on the scaled internal concentration (SIC) either with a constant or a time-variable exposure concentration profile.
The two variants are implemented: the stochastic death variant (GUTS-SIC-SD) and the individual tolerance variant (GUTS-SIC-IT). See [1, 2] for details.

Input your concentration profile

Please upload a two-column file in text format. Default is comma-separated values but other separators can be chosen. Columns with headers must be the followings:
1. The time points at which you measured concentrations (header = 'time');
2. The measured concentrations (header = 'conc').
In case of constant exposure, the second column must be filled-in with the same value whatever the time point.

Model parameters

Please choose a value for parameter hb ([time]-1 ) which is the background mortality of your species, then a value for the dominant rate constant kd ([time]-1) of the TK part of the GUTS model.
Please choose GUTS-SIC-SD parameters, that is the threshold concentration Z ([concentration]) for all individuals corresponding to the no effect concentration for the chemical under consideration and the killing rate kk ([concentration] -1.[time]-1)
Please choose GUTS-SIC-IT parameters, that is the median α ([concentration]) of the threshold concentration distribution among individuals (log-logistic law) and the shape of this distribution, β (dimensionless).

Margin of Safety

Please choose a multiplication to apply to your exposure profile.

Model simulations


Download Plot
Download Profiles Data


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.


Sandrine CHARLES, professor at University Lyon 1
Virgile BAUDROT, CNRS post-doc
Maud REPELLIN, bachelor student at University Lyon 1