DEBtox information
Making sense of ecotoxicity test results

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DEBtox information

DEBtox information


Welcome to the DEBtox information site

Welcome to the DEBtox information page, the site for people that want to make sense of ecotoxicity data. This site contains information on mechanistic models for the analysis of stressor effects on the life-history traits of individual organisms (and from there to higher and lower levels of biological organisation). Specifically, this site is about models based on animal energy budgets (DEBtox and DEBkiss) and survival models from the GUTS framework.

This website constitutes a node in the international DEBnet network, together with the associated site of DEBtox Research.

The mission of  is to simplify biology to get to the essence of what toxicants (and other stresses) are actually doing to organisms. Simplification is necessary if we need to gain understanding. Furthermore, we cannot expect to test even a small fraction of all possible (combinations of) toxicants, species and environmental conditions. Once we get to the essence, it is possible to make educated predictions of toxicant effects for untested chemicals, untested species, and under untested conditions.

Here, you can find information, lists of relevant publications, (links to) free e-books, and freely downloadable Matlab packages to analyse your data. Use the major categories on the top left of the screen to navigate through this site; the corresponding sub-categories will appear right next to it in the submenu.


The free and open-source software openGUTS is now available for download! It is available as a standalone Windows executable or as Matlab package. It supports the use of GUTS for regulatory purposes, but will also prove useful for scientific studies. The dedicated website provides more information.

WARNING! A calculation error was spotted in openGUTS, which may affect IT calibrations/predictions for specific types of exposure scenarios. The Matlab version has been updated to v1.1 to repair this. For more information, see the openGUTS website.

WARNING! For users of BYOM versions before v. 4.3, see the notes and warnings on the BYOM page (bottom of page).
If you are working with BYOM, and would like to be notified immediately in case of errors, new versions, etc., email me and I will include you in a mailing list. I may also use this mailing list for other important developments such as new (versions) of the e-books, and new papers. This saves you the hassle of checking this website every week ;-).

                DEBnet network of experts

The Duck of Vaucanson

Upcoming courses and events

  • Dedicated 2-day GUTS courses, geared towards professionals in risk assessment of pesticides. Wageningen, the Netherlands, dates to be announced. More information.
  • In August 2021, we will again organise our much-praised summer school "Dynamic modelling of toxic effects" in Denmark. More information on the course page. Download 2020 flyer. NOTE: due to the COVID-19 situation, the 2020 course was cancelled; we hope things will be normalised by summer 2021.
  • Roman Ashauer and myself gave an on-line short course on openGUTS at the 2020 SETAC SciCon. This course is now available for everyone via Leanpub: Although you don't get the interaction with the instructors, this is still a nice way to educate yourself in quarantine.
  • In May 2021, there will be the next run of the DEB school and the DEB symposium. This time, the venue is Halifax, Canada. More information. Note that part of the DEB school will be in tele mode, and there probably will be some way to join the symposium in virtual mode.

Job opportunities for modellers

  • Nothing at the moment (that I know of).

Latest news

  • 11 October 2020: our 2011 GUTS paper has now reached 200 citations in Web of Science!
  • 28 September 2020: spotted an error in the no-shrinking equations that are used in the DEBkiss and DEBtox2019 packages. This error could bias calibrations, though the simulations were fine. These packages are thus updated. This error does not affect the DEBtox_classic package since there is no option to prevent shrinking in that one. See the BYOM page.
  • 26-27 September 2020: update of the BYOM tox-related packages. GUTS package: this update is especially a good idea when using the ODE-solver versions in the "experimental" folder. DEBtox2019 and DEBtox_classic packages: more efficient/accurate ODE solving for time-varying exposure. For all these packages: now allowing double time points in the exposure definition (as in openGUTS). See the BYOM page.
  • 24 September 2020: update for BYOM to version 5.2. Modified the parameter-space explorer to work reasonable well for 6/7 free parameters (best left to experts). Further modifications for time-varying exposure, now allowing double time entries like in openGUTS and efficiency improved for hard-pulsed exposure (these changes also require updates for the packages that use glo.break_time ... working on that!). See the BYOM page.
  • 30 August 2020: update for BYOM to version 5.1. Nothing spectacular, just fixed a few bugs and added a few bells and whistles. See the BYOM page.
  • 2 June 2020: update for the BYOM package for classic DEBtox and DEBkiss to match it to BYOM 5.0. See the BYOM page.
  • 29 May 2020: update for BYOM to version 5.0. This is a major update, with much new functionality (incl. the parameter-space explorer from openGUTS). See the BYOM page. Also an update of the GUTS and DEBtox2019 packages to make use of the new functionality!
  • 11 Dec. 2019: new paper presenting an updated simplified DEB model for ecotoxicology (based on DEBkiss, compound parameters). See
Older news over here.

The DEBtox information site,, since July 2011