Assessment of chemicals

The OECD QSAR Toolbox


To increase the regulatory acceptance of (Q)SAR methods, the OECD is developing a QSAR Toolbox to make (Q)SAR technology readily accessible, transparent, and less demanding in terms of infrastructure costs.


Download the Toolbox      Guidance Documents and Training Materials     Webinar      Help Desk      Public Discussion Forum      


What's new?

20 September 2021 – An updated version of the QSAR Toolbox 4.5 was released.

The QSAR Toolbox 4.5 includes the following updates:

  • New functionnalities/improvements: 
  1. Workflow editor allows automated and standardised workflows for predicting or grouping of chemicals to be developed by the users
  2. IUCLID Plug in allows users to enter target chemical by IUCLID ID, use composition search in IUCLID databases, and import from IUCLID
  3. Pilot version of web client available as part of the standard installation provides basic features from the Simplified UI along with a dedicated module for searching in imported IUCLID databases
  4. Automated Workflow for Skin sensitization for Defined approaches (DASSAW) was updated based on the protocol of the DASS guideline (OECD Guideline No. 497).
  • New databases:
  1. Human skin sensitisation NICEATM/BfR - New: 1 377 substances and 2 277 data points
  2. Photosensitivity database - New: 73 substances and 563 data points.

The new installation can override the exiting QSAR Toolbox the former version in your computer or can be installed as a new product in your computer where the former version is not installed. 


For the complete list of changes, please see the release notes, Download the QSAR Toolbox and find more information on the QSAR Toolbox website, and access the new repository.

What is the qsar Toolbox ?

The Toolbox is a software application intended to the use of governments, chemical industry and other stakeholders in filling gaps in (eco)toxicity data needed for assessing the hazards of chemicals. It has been developed in close collaboration with the European Chemicals Agency. The Toolbox incorporates information and tools from various sources into a logical workflow. Crucial to this workflow is grouping chemicals into chemical categories. Please consult

The seminal features of the Toolbox are:

  1. Identification of relevant structural characteristics and potential mechanism or mode of action of a target chemical.
  2. Identification of other chemicals that have the same structural characteristics and/or mechanism or mode of action.
  3. Use of existing experimental data to fill the data gap(s).

The Toolbox has benefitted from the contributions of numerous experts in governments, NGOs and the chemical industry. The software was developed by the Laboratory of Mathematical Chemistry.

The toolbox also provides an approach to predict skin sensitisation based on the concept of Adverse Outcome Pathways. The Toolbox has been developed in several phases:


  1. to emphasise technological proof-of-concept (version 1.0 released in 2008);
  2. to develop a more comprehensive Toolbox which fully implements the capabilities of the first version launched in 2008 (version 2.0 released in 2010, version 3.0 released in 2012);
  3. 3rd Toolbox generation, containing new features launched in 2012.
  4. version 4.0 was released in April 2017.
  5. version 4.1 was released in August 2017.
  6. version 4.2 was released in February 2018.
  7. version 4.3 was released in February 2019.
  8. version 4.4 was released in February 2020.
  9. version 4.5 was released in September 2021.



Webinar by OECD & ECHA QSAR Toolbox Version 4.0 Features - June 2017


The purpose of this webinar was to demonstrate the new features of Version 4.0 of the QSAR Toolbox.

OECD: Brief overview of the purpose & history of the QSAR Toolbox. Basic concepts and organisation of the Toolbox including workflow, profilers, databases. Where to get support for Version 4.0 (tutorials, discussion forum).

ECHA: Practical examples for the use of the QSAR Toolbox v4.0, with focus on the new functionalities. Relevance of profilers and databases for a given endpoint. Automated and standardised workflows. Quantitative metabolic information. Improved reporting: new prediction report and exportable data matrix in excel format.

The functionalities of the new version were presented at the 2017 IT tools training during ECHA´s stakeholders´ day.

Watch the training video providing an overview of the QSAR Toolbox.

Download the QSAR Toolbox

The latest version of the QSAR Toolbox (version 4.5) as well as instructions for installation and how to get started are available at and  

This includes release notes, installation manual, QSAR Toolbox Server Manual quick reference guide for getting started and other tutorials. 

Extensions for the QSAR Toolbox are available at


- Due to the size of the files, the downloads may take a few minutes.


Presentations, Manuals and Training Materials for Using the Toolbox

The presentations of the QSAR Toolbox are available at

The following manuals and tutorials are available at

I. Manuals

Application manual of OECD QSAR Toolbox v.4.4

2 Quick reference guidance for getting started
3 Manual for creating prioritisation schemes (using the Profiling Scheme Editor)
II. Step by step approach for predicting
1 Step-by-step example on how to predict the skin sensitisation potential approach of a chemical read-accross based on an analogue approach 
2 Step-by-step example for predicting Ames mutagenicity by making use read-accross
3 Step-by-step example on how to predict acute aquatic toxicity to Daphnia for the 3-ethyl-5-methyl-3-methoxyphenol by the trend analysis approach
III. Step by step examples for introducing basic functionalities
1 Step-by-step example of how to evaluate an ad-hoc category of aliphatic amines and to predict an ecotoxicological endpoint
2 Step-by-step example of how to build an user-defined linear profiling scheme
3 Step-by-step example for building QSAR model
4 Example for predicting skin sensitisation potential of (2E,6Z)-2,6-nonadien-1-ol accounting for skin metabolism
5 Step-by-step example for predicting skin sensitization accounting for abiotic activation of chemicals
6 Example for predicting acute aquatic toxicity to fish of mixture with known components
7 Example for predicting Skin Sensitization of mixture
8 Implementation AOP workflow in Toolbox: Skin Sensitization
9 Examples illustrating customized search (Query Tool) in Toolbox
10 Example illustrating endpoint vs. endpoint correlation using ToxCast data
11 Example illustrating endpoint vs. endpoint correlation for apical endpoints

Predicting acute aquatic toxicity to fish of Dodecanenitrile (CAS 2437-25-4) taking into account tautomerism

IV. Step by step examples for introducing new functionalities of Version 4
1 Tutorial on how to predict skin sensitisation potential by automated workflow
2 Tutorial on how to predict skin sensitisation potential by standardized workflow
3 Tutorial of how to use Automated workflow for ecotoxicological prediction
4 Tutorial of how to use Standardized workflow for ecotoxicological prediction
5 Tutorial illustrating new options for grouping with metabolism
6 Tutorial on how to predict Skin sensitization potential taking into account alert performance
7 Tutorial illustrating quantitative metabolic information and related functionalities
8 Tutorial for using the PBT prioritization scheme
9 Tutorial on SMARTS structures search
10 Tutorial of how to Import/Export a custom database and Import/Export IUCLID
11 Tutorial illustrating new options of the structure similarity
V. Step by step examples for introducing new functionalities of Version 4.2

Category elements for assessing category consistency

2 Example illustrating RAAF scenario I and related assessment elements
3 Example illustrating RAAF scenario II and related assessment elements
4 Example illustrating RAAF scenario III and related assessment elements
5 Example illustrating RAAF scenario IV and related assessment elements
6 Example illustrating RAAF scenario V and related assessment elements
7 Example illustrating RAAF scenario VI and related assessment elements
8 Manipulation of datamatrix and manual transferring of data to the target outside data gap filling module
9 Evaluating alert performance accounting for metabolism
VI. Step by step examples for introducing new functionalities of Version 4.3

Step-by-step example on how to use the (Q)SAR editor


Step by step example on how to implement AOP information from Effectopedia Wizard to Toolbox


Step-by-step example on how to build an user-defined profiling scheme accounting for the (a)biotic activation of the chemicals


Previous version of the QSAR Toolbox and manuals/tutorials 

The OECD does not foresee to organise training sesions for the use of the Toolbox. Training sessions are organised by other organisations which are referenced:

Help Desk

The QSAR Toolbox helpdesk provides support. The helpdesk may address issues related to:

  • User registration on the toolbox download page
  • Download of the system
  • Installation of the system
  • Basic usage of the system
  • Common usage scenarios
  • Bugs or crashes of the system


The support helpdesk is not able to address issues related to:

  • Solving complex cases
  • Requests for new features 

Public Discussion Forum

A QSAR Toolbox Discussion Forum is available where users can:

  • exchange experience with using the software (tips and tricks),
  • seek guidance,
  • exchange databases,
  • exchange user defined profilers and QSARs, and
  • make suggestions for improvements.


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