Toxic hazard classification by Cramer (extended)

Toxic hazard classification by Cramer profiler (extension) is built on basis of original paper of Cramer [1] and its augmented version commented in paper of Patlewicz [2]. Categorization rules classifying chemicals into different levels of toxicological concern (when administered orally) are organized in tree-like scheme. Decision tree comprises 33 basic structural rules, which are same as in the original paper and 5 new additional rules which are:

• Q40: Possibly harmful organophosphate or organophosphothionate
• Q41: Removes phosphates
• Q42: Possibly harmful analogue of benzene
• Q43: Possibly harmful divalent sulphur (not detected via Q3)
• Q44: Free a,b-unsaturated heteroatom

The entered target chemicals are classified in one of the three toxic classes Low (Class I); Intermediate (Class II); High (Class III). The Cramer classification scheme is used in many approaches for assessing the toxicological profile of the chemicals. It was first implemented in Toolbox 2.0 and regularly modified during the years generally due to discrepancies in the classification result when compared with other in silico tools (e.g. ToxTree). Toolbox will provide two profiling results: for parent and metabolites respectively in the following cases:

• When the chemical undergoes different type metabolism such as hydrolysis or unsulphonation/unsulphatation (e.g. CAS 99287-30-6 Azuletil sodium (KTI-32))
• When mixtures are assessed. In this case TB will provide profiling results for each component of the mixture individually.

1. G.M. Cramer and R.A. Ford Estimation of toxic hazard - a decision tree approach. Food and Cosmetics Toxicology, Volume 16, Issue 6, December 1978, Page 255-276.

2. G. Patlewicz, N.Jeliazkova, R.J. Safford, A.P. Worth, B. Aleksiev. An evaluation of implementation of the Cramer classification scheme in the Toxtree software. SAR and QSAR in Environmental Research. Vol. 19, Nos. 5-6, July-September 2008, Page 495-524.

For suggestions on improvement or bug fixing of the plug-in, please contact its developer directly.