ToxRTool - Toxicological data Reliability Assessment Tool


Evaluation of the reliability of toxicological data is of key importance for regulatory decision-making. Currently, the so-called Klimisch categories (Klimisch et al., 1997, Regul Toxicol Pharmacol. 25, 1-5) are often assigned to data in several regulatory programmes:

Category 1: reliable without restrictions

Category 2: reliable with restrictions

Category 3: not reliable

Category 4: not assignable.

Although well established and widely used, the Klimisch categories lack, however, detailed criteria for assigning data quality.

The software-based tool “ToxRTool” (Toxicological data Reliability Assessment Tool) was developed within the context of an ECVAM funded project to provide comprehensive criteria and guidance for evaluations of the inherent quality of toxicological data, thus making the decision process of assigning reliability categories more transparent and more harmonised.

ToxRTool consists of two parts, one to evaluate in vivo and one to evaluate in vitro data. It is applicable to various types of experimental data, endpoints and studies (study reports, peer-reviewed publications) and leads to the assignment to Klimisch categories 1, 2 or 3.

The primary result of the tool is the assignment of Klimisch categories 1, 2 or 3. Additionally, the tool offers the option to assign a Klimisch category according to personal judgement. If this personal judgement differs from the tool outcome, the evaluator is requested to document the reasons. 

Prototypes of the tool were tested in two independent experiments in which the tool was used by experienced toxicologists and risk assessors ('raters'). Their tool-independent appraisal of the data quality of a defined data set was compared with the suggested conclusion of the tool. This approach allowed the analysis of the performance of the tool in practice and the identification and minimisation of sources of non-optimal objectivity and heterogeneity in evaluation results (Schneider et al., 2009, Toxicology Letters 189(2): 138 – 144).

The ToxRTool is publicly available for use and we invite the scientific and toxicological community to make use of this application.

To apply the ToxRTool please proceed as follows:

  1. Read the enclosed pdf iconInstructions for use.
  2. Download and fill in the excel iconToxRTool”.



Copyright Notice

The ToxRTool is the outcome of a project sponsored by the European Commission (CCR.IHCP.C433199.XO). The ToxRTool is property of the European Commission: © European Communities. All rights reserved.

All uses of the ToxRTool in its original version without introduction of changes are authorised, except for commercial purposes, on the condition that the source is fully acknowledged in the form " Source: European Commission, JRC, IHCP, In Vitro Methods Unit/ECVAM, and written notification must be given to Changes made to the ToxRTool are not authorised. All general Copyright & Disclaimer provisions to apply as stated in the Legal Notice.