Medical Aspects of Assistance and Protection against Chemical Weapons

Medical Management of Chemical Warfare Casualties


Main Clinical Signs and Symptoms

Medical personnel should familiarise themselves with the main clinical signs and symptoms of chemical warfare casualties.

This will allow them to determine a clinical diagnosis and start the triage process, assigning priority for decontamination and medical treatment.



Clinical Manifestations Vary

The nature and timing of these clinical manifestations will vary with the duration and concentration of exposure, and with the route of exposure, which should be considered in the differential diagnosis and triage process.

Example: nerve agents and cyanides (blood agents) absorbed by inhalation have rapid onset of effects and need immediate treatment.

Indirect Effects of Chemical Exposure

Differential diagnosis should also consider the indirect effects of chemical exposure, including heat stress from wearing protective equipment, psychological effects, and even side effects from antidotes. This is particularly important when exposure to an agent has not taken place but antidotes have been administered.

Example: auto-injectors with nerve agent poisoning antidotes.

Differential diagnosis and triage may also be complicated in cases of mixed casualties who have both conventional and chemical injuries.



Antidotes are available for some chemical warfare agents, however, their availability will depend on local, regional and national medical doctrines, policies, and regulations.

When specific antidotes are not available, therapy will be limited to supportive care.

Medical Symbol


In a chemical mass casualty situation medical resources will be overwhelmed.

Triage is a medical decision process used to arrange patients in order of priority, to ensure the most effective use of limited medical resources and minimise morbidity and mortality.

Triage is used to assign priority for treatment, evacuation, and decontamination.

One of the most commonly used systems for chemical triage contains four categories: Immediate, Delayed, Minimal, and Expectant.


Practical Guide for Medical Management

The OPCW’s Practical Guide for Medical Management of Chemical Warfare Casualties includes information on specific antidotes for chemical weapon agent poisoning, triage of chemical casualties, and other useful information regarding medical management of chemical weapons victims.

Symptoms and Signs of Exposure to Different Classes of Chemical Weapon Agents

Target Organs Classes of Agent
Central Nervous System

Seizures, coma, hypoxemia, hyperthermia


Blood/ Nerve/ Blister/ BZ

Eye, Nose and Skin

Constricted pupils

Dilated pupils

Dry mouth and skin

Eye irritation

Blistering skin






Blister/ RCAs/Lung Irritants


Blood/ Lung/ Nerve/ Blister

Respiratory Tract


Copious secretions

Respiratory distress

Pulmonary oedema


Blood / Lung / Blister / Nerve


Nerve / Lung /Blister

Lung / Nerve /Blister

Digestive Tract




Lung / RCAs / Blood /Nerve






Long-Term Consequences of Exposure to Chemical Warfare Agents

The clinical symptoms and signs shown in the diagram are intended to provide preliminary guidance to the type of chemical warfare agent that a casualty may have been exposed to. This is based on the commonly expected symptoms caused by different classes of chemical warfare agents.

Patients may present differently

Exposure to uncommon chemical warfare agents and many toxic chemicals could result in additional symptoms and signs being exhibited. 

Medical practitioners should consult OPCW’s Practical Guide for Medical Management of Chemical Warfare Casualties for further information to help them make clinical diagnosis.