The need to consider the problem of acute toxic injury in the prehospital context emphasized by the recent use of highly toxic agents of warfare in terrorist attacks. Toxic agents differ widely in their nature but may be considered to have four distinct properties: toxicity, latency, persistency and transmissibility. Toxicity and latency determine the onset and pathophysiology of the poisoning and therefore the clinical management. Persistency and transmissibility determine the level of hazard to rescue personnel and the evacuation system and therefore the rationale of logistic management. Previously, special emphasis has been given to the importance of isolation and decontamination of the patient before any medical intervention can occur. This approach, however, although essential for the safety of medical responders may not be in the best interests of the patient who may be in a life-threatening situation within a contaminated zone (CONZONE). Toxic injury may require more rapid help than traumatic injury; moreover, traumatic and toxic injury may co-exist, as in the case of explosion with toxic emission. The special skills required are defined in the TOXALS programme and must now become a standard part of the training and practice of prehospital care medical care.