Thermal decomposition of atrazine and its toxic products†

Atrazine (ATZ) is one of the most widely used herbicides and is highly scrutinized due to its environmental impact. Given its extensive use, ATZ is likely to be exposed to high-temperature conditions such as those encountered during wildfires, incineration, or thermal desorption processes. However, there are limited experimental data on the thermal decomposition of ATZ. The present study investigates the decomposition of ATZ in a flow reactor constructed of α-alumina at temperatures between 400 and 800 °C. At temperatures above 400 °C, thermal decomposition was observed to occur and the formation of HCl and several hazardous chemicals, including hydrogen cyanide and cyanoacetylene were observed during the thermal decomposition of ATZ. Quantum chemical calculations were also performed to elucidate the decomposition pathways and determine the relevant reaction rates. These findings provide crucial insights into the risks associated with exposing ATZ to high temperatures and the potential release of harmful gases from its thermal decomposition.