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 doing to organisms. Simplification is necessary if we want 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 sub-menu.

                DEBnet network of experts

The Duck of Vaucanson

Errors and warnings

For users of BYOM versions before v. 5.0, see the notes and warnings on the BYOM page (bottom of page). But, really, you should have updated long ago! 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 ;-).

Summary of more recent errors in BYOM. For more detail, check the BYOM page.

Error in BYOM version 4.5-6.2. I found an error in calc_parspace, in the 'extra sampling' code block. C
orrected in BYOM v.6.3.

Matlab R2023a throws errors in BYOM v.6.5 and earlier. The newest version of Matlab does not allow the cell-array format for name-value pairs anymore. Solved with the update to BYOM v.6.6.

Issues with moving-time-window EPx calculations in BYOM v.6.4-6.6. Issues with the reporting of the function calc_epx_window_batch. Error in the EPx calculations,
leading to erroneous calculations when the exposure scenario has a low time resolution. Both issues repaired with the update to BYOM v.6.7.


OpenGUTS v1.2. The free and open-source software openGUTS v1.2 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. For more information on this software and the changes relative to previous versions, see the openGUTS website.

Changes at Leanpub (keeping my e-books free). Things changed a bit at Leanpub. My free e-books, from some point onward, required a paid membership to Leanpub for free download. While I do want to support Leanpub, I want most of my e-books to be really free (and free of access hurdles). And, I am not sure whether the people that are interested in my books would also have an interest in the other books offered at Leanpub. I noticed this change at Leanpub on 19 Sept. 2022, and immediately changed the settings so my free e-books are again totally free. I noticed that some of my e-books are also offered on other (rather shady) web sites. Please get them through Leanpub only!

DeEP tool. Take a look at the DeEP tool for EPx predictions with DEBtox2019. Note that this tool does not perform calibrations or validations on data sets, but rather makes EPx predictions for exposure profiles, such as those from FOCUS calculations. BYOM contains a function to translate calibration output to a DeEP input file. There also have been dedicated short courses for this tool at SETAC-Europe conferences. Note that the DeEP site hosts an on-line calculation tool, but also a downloadable setup file for a standalone application. 

Upcoming courses and events

  • Roman Ashauer and Tjalling Jager 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 at home.
  • A next run of the DEB school and symposium is planned for the first half of 2025. More information will become available here.
  • The next TKTD Autumn School on dynamic modelling of toxic effects is planned to run in Oct-Nov 2024. More information is available at the course page from Copenhagen University here. The course will have an on-line part and an on-site part in Denmark.
  • The PrediTox winter school is running again from 27-31 January 2025 in Lyon, France (with a few spaces for virtual participation). Among the topics is also TKTD modelling with GUTS. More information.
  • ...

Job opportunities for TKTD/DEB modellers

  • Nothing that I know of at the moment.

Latest news

  • 28 April 2024: my paper on identifying and predicting delayed mortality with GUTS is now officially published in an issue of ETC. Available via DOI or contact me for a PDF.
  • 22 April 2024: the GUTS e-book was positively reviewed in IEAM.
  • 9 April 2024: adding a BYOM package for GUTS-immobility, expanding GUTS to distinguish between (reversible) immobility and (irreversible) death. A publication on this model is upcoming. This package requires BYOM v.6.9 (or newer). See BYOM downloads page.
  • 9 April 2024: new version 6.9 of BYOM, with small updates and preparation for the GUTS-immobility package. See BYOM downloads page.
  • 20 March 2024: release of an update of the openGUTS standalone to v.1.2 so fix an error message for (very) specific data sets and to calculate additional LCx values to support risk assessment for bees following the EFSA guidance. See openGUTS download page. The Matlab version has also been updated to v.1.2 (it did not suffer from the error in the standalone, but the additional LCx are now, by default, produced).
  • 8 March 2024: UBA report "Critical evaluation of effect models for the risk assessment of plant protection products" was just published. Download link.
  • 28 February 2024: new paper out on identifying and predicting delayed mortality with GUTS. Still 'early view' but available as formatted PDF. Available via DOI or contact me for a PDF.
  • 5 February 2024: minor update of the DEBkiss e-book. See the support page.
  • 5 December 2023: new paper of Romoli et al on-line! In this paper, we compare standard DEB-TKTD with DEBtox (DEBkiss-TKTD) on typical datasets for environmental risk assessment of pesticides. Download from publisher's website. (available open access now!)
  • 22 September 2023: new version of the DEBtox_classic package for BYOM. Small changes to make the calculations more efficient, and allowing for time-to-death data. See version log for all changes. See BYOM downloads page. Note that using time-to-death data also requires updating to BYOM v.6.8.
  • 21 September 2023: new version of the GUTS package for BYOM. Small changes to make the calculations more efficient, and allowing for time-to-death data. See version log for all changes. See BYOM downloads page. Note that using time-to-death data also requires updating to BYOM v.6.8.
  • 18 September 2023: small update of BYOM. Added an option to use time-to-death data, small functionality improvements for EPx calculations, preparations for the DEBtox_mix package. Also added the experimental DEBtox_mix package for DEBtox2019-based analysis of binary mixture data. See BYOM downloads page.
  • 18 September 2023: removed the menu entry for the DEBtoxM software. The last update was in 2015, and I do not maintain nor use this software anymore. The web page still exists here, so old links will still resolve.
  • 7 August 2023: released a new version of the "Making sense ..." e-book. The most important change is a complete overhaul of the case studies to reflect the latest thinking and methods for DEB-based TKTD analysis. More information.
  • 20 July 2023: released a new version of the GUTS e-book, adding a.o. a new case study with openGUTS. More information.
Old 'news' over here.

The DEBtox information site,, since July 2011