Cramer decision tree

Collectively, the work by Mimro et al. (1996) and Kroes et al. (2000, 2004) proposed several thresholds of toxicological concern based on toxicological and structural classifications. Table 7.2 summarizes these thresholds, which are cumulative as dietary concentrations increase. These thresholds are based on the analysis of compounds grouped using the so-called Cramer decision tree and on the structural analysis of compounds testing positive for specific toxic endpoints. Maintenance of such a system depends upon maintenance of the decision tree and the ability to continue to discern relationships between toxicity effects and structural information and to then translate those relationships into a decision tree. 

The decision tree method of Cramer et al. (1978) was based on the toxicological data then available and used a series of 33 questions, each leading either to another question or to classification into one of three classes of presumptive toxicity. The questions were primarily based on chemical stmcmre, but namral occurrence in body tissues or fluids as well as natural occurrence in traditional foods was also considered. The three classes of substances were defined as follows ... 

CPDB. 2007 The carcinogenic potency database website, http //potency.berkeley.edu/cpdb.htnil Cramer, G.M., R.A. Ford, and R.A. Hall. 1978. Estimation of toxic hazard - A decision tree approach. Food Cosmet. Toxicol. 16 255-276. 

Cramer C.M., Ford R.A., Hall R.L., (1967) Estimation of a toxic hazard - a decision tree approach. Food and Cosmetics Toxicology 5, pp 293-308. 

Cramer GM, Ford RA, Hall RL. Estimation of toxic hazard—A decision tree approach. J Cosmet Toxicol 1978 16 255-76. 

Cramer, G., R. Ford, and R. HaU, 1978. Estimation of toxic hazard—a decision tree approach. Food Gosrrtet. 

The threshold of toxicological concern (TTC) describes a level of toxicant exposure that represents negligible risk to human health or the environment. In some situations, this is also referred to as a de minimis level. Data-poor chemicals often are classified using TTC as a surrogate for definitive toxicity data [6]. Decision trees are often constructed using the original classifications by Cramer and co-woikers [33], which are as follows ... 

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