Flammability and toxic gas emissions from the thermal decomposition of insecticides: assessing fire and environmental safety

The aim of the study was to assess the flammability properties and characterise the toxic gas emissions generated during the thermal decomposition of selected insecticides containing the active substances cypermethrin, pirimicarb and flonicamid. The tests included measurements of the reaction to heat using a cone calorimeter (ISO 5660) and analysis of combustion products in a tube furnace using FT-IR (GASMET DX-4000). Products containing cypermethrin (EC formulations) showed the highest fire risk, very rapid ignition, high pHRR values and intense smoke comparable to hydrocarbon fuels. Pirimicarb preparations were characterised by moderate flammability, while flonicamid (WG) showed the lowest flammability. Gas analyses showed a clear influence of ventilation conditions: with good air flow, CO 2 and SO 2 dominated, while with limited air flow, CO, HCN and formaldehyde concentrations increased significantly, in some cases to life-threatening levels. Flonicamid also caused HF emissions, and pyrethroid formulations caused increased concentrations of NO 2 and HCl. The results indicate significant fire and toxicological hazards associated with the storage and combustion of PPPs. Due to the limited number of studies, the authors consider the results to be preliminary and recommend further comprehensive research and the inclusion of these hazards in risk assessments.