- The Tokyo subway sarin attack in March 1995 demonstrated the importance of preparedness toward a chemical terrorist attack. Emergency medical teams on the scene are valuable, beside the medical treatment of casualties, in the cognition of toxicant involvement and later in the recognition of the specific toxidrome involved. The chemical terrorism scene is a contaminated area; therefore, first responders have to be protected from both percutaneous and inhalational exposure to toxic materials. This protection is also against secondary evaporation (gas-off) from contaminated casualty, hence the importance of disrobing casualties on the scene as soon as possible. Once the recognition of toxicological involvement have been made, the next crucial decision is whether the clinical toxidrome is of cholinergic toxicity (e.g. organophosphate or carbamate intoxication) in which there are automatic injectors for treatment available on the scene, or any other toxidrome (such as irritation or vesicants) in which, beside general measures, like oxygen delivery and airway support, there is not a specific antidotal treatment on the scene. The clinical detection and identification of the chemical toxidrome involved is of utmost importance since it promotes the antidotal treatment quickly and efficiently. The key to the medical management of such events is based on decisions that have to be taken as soon as possible according to the clinical judgment of medical teams on the scene.