Several nitroarenes were decomposed isothermally in dilute supercritical solution in benzene or toluene and in the vapor phase in the temperature range of 290-380 OC in sealed glass tubes with pressures up to 100 MPa. The mechanii of thermolysis are inferred from kinetic studies and product analysis. The initial rate-controlling step for nitrobenzene and p-nitrotoluene decomposition is probably intermolecular hydrogen abstraction to form ...