The World Health Organization (WHO) has released an updated interim clinical guidance to help health-care workers manage patients exposed to chemical weapons and other hazardous or toxic chemicals, according to a press release issued in Geneva on 4 June 2026. The revision builds on WHO’s 2014 publication and integrates new scientific evidence, evolving threat profiles, and lessons learned from recent chemical exposure incidents. It applies an ‘all hazards approach’ to natural, accidental, or deliberate threats. The document targets frontline health-care workers in emergency departments, hospitals, and other facilities. It aims to strengthen national preparedness for chemical incidents.
Armed conflicts can lead to accidental or intended releases of toxic chemicals, exposing civilians, including children, women, and displaced populations, to burns, trauma, and other consequences. Such exposures can be fatal or cause long-term disability due to critical gaps in specialized training, essential equipment, and clear referral pathways. The Chemical Weapons Convention, with 193 States Parties and implemented by the Organisation for the Prohibition of Chemical Weapons, prohibits the development, production, stockpiling, transfer, and use of chemical weapons. Risks have also grown from accidental leaks of toxic industrial chemicals and the use of riot control agents such as tear gas in conflict and protest settings. The original WHO guidance dates from 2014.
The 2026 update incorporates findings from a rapid systematic review of literature published between 2014 and March 2026. Key revisions include updated treatment guidance for toxic industrial chemicals such as chlorine and phosgene, and refined decontamination procedures and terminology. The document also includes updated evidence and references aligned with current international best practices. Clinical considerations for riot control agents and white phosphorous have been expanded. Clinical algorithms, symptom tables, and treatment protocols have been refreshed while preserving the user-friendly structure of the 2014 version.
WHO encourages Member States at risk of increased chemical incidents to map major chemical facilities and prioritize training for first responders and health-care personnel. This ‘map and prioritize’ approach was applied in Ukraine, where WHO trained over 2800 responders and more than 25 medical facilities at the request of the Ministry of Health. WHO also provides online courses on chemical hazards and a factsheet on white phosphorus, an incendiary agent known for causing deep-tissue burns. The guidance reaffirms a core principle: “immediate threats to airway, breathing, and circulation should be managed without delay when it is safe to do so and when responders are adequately protected.” It is designed to remain applicable in resource-limited and mass casualty settings.
The update was coordinated by a WHO technical team with contributions from international experts in clinical toxicology, emergency medicine, and chemical incident response. Declarations of interest were reviewed under WHO policy, with no financial conflicts identified. Published as ‘interim guidance,’ the document reflects the evolving nature of chemical threats and medical countermeasures. It is available under a Creative Commons license to support broad dissemination and adaptation. WHO acknowledges the financial support provided by Canada’s Weapons Threat Reduction Program (WTRP) for the development of the guidance.
