Toxicological Characterization of the Thermal Decomposition Products of Chemicals: a New Approach to an Old Problem

Different calorimetric techniques coupled with chemical analyses and ecotoxicological bioassay led to the proposal of suitable protocol for the definition of a KPI (Key Process Index) useful to rank a compound in respect to the toxicological profile of its thermal decomposition products. Fenitrothion was used as example and showed to decompose through a series of two main processes, the first being less severe than the second. It is demonstrated that similar ecotoxicological results can be gathered both using adiabatic and Isothermal conditions. This allows to exclude a priori the necessity of carrying out the more difficult and time and money consuming adiabatic experiments. The analytical characterization of the samples collected during a series of isoperibolic (quasi-isothermal) experiments allowed to calculate, using the software ECOSAR, the toxicological profile of the intermediate compounds.