Sensitive equipment materials were decontaminated from organophosphorus compounds paraoxon or parathion by immersion into a catalytic reactive solution and by spraying with the same solution. Immersion of contaminated material samples into methanol-based catalytic solutions resulted in an effective decontamination. Greater than 99% decontamination was observed for paraoxon on high-impact polystyrene (HI-PS) over 15 min of reaction time. Under the same process conditions, the decontamination from parathion did not exceed 95%. The catalytic decompositions of paraoxon and parathion followed first-order reaction kinetics with rate constants of 5.4 x 10(3) and 1.3 x 10(3) s(1), respectively. These values were by an order of a magnitude lower than the respective rate constants reported for homogeneous reactions in a methanol solution. Decontamination by spraying the catalyst on the contaminated surface revealed that multiple applications would be required to overcome a rapid evaporation of methanol from the surface and an associated loss of catalytic activity.