Empowering health-care workers to save lives after toxic chemical exposures: WHO interim clinical guidance

Geneva, 4 June 2026 | WHO has updated its guidance for the clinical management of patients exposed to chemical weapons or other hazardous or toxic chemicals.

Armed conflicts can lead to accidental or intended releases of toxic chemicals, putting civilians - including children, women, and displaced populations - at risk of burns, trauma, and other consequences. These exposures can be deadly or lead to long-term disability, not only because of the severity of injuries but also due to critical gaps in specialized training, essential equipment, and clear referral pathways for the events.

WHO applies an 'all hazards approach' to address natural, accidental or deliberate threats to mitigate the health impacts. The core principles - early recognition, protection of health-care workers, rapid decontamination, structured triage, and timely antidotal and supportive care - remain essential for managing toxic chemical exposures of any origin.

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.

Member States at risk of increased chemical incidents are encouraged to map major chemical facilities and prioritize training for in-charge first responders and health-care personnel. This approach - map and prioritize - was used in Ukraine, where WHO trained over 2800 responders and more than 25 medical facilities at the request of the Ministry of Health.

In addition to risks from accidental leaks of toxic industrial chemicals, the use of riot control agents, such as tear gas, has increased in conflict and protest settings.

Strengthening preparedness to respond to toxic chemical exposures through WHO tools and training

WHO provides a range of tools to support national preparedness for toxic chemical exposures, including the following WHO online course series:

Chemical Hazards Part I: Introduction to Chemical Hazards

Chemical Hazards Part II: Elements for Assessment

Chemical Hazards Part III: Immediate Actions at the Event Site

WHO has also published a Factsheet on white phosphorus, an incendiary agent known for causing deep-tissue burns.

To address the clinical management of toxic chemical exposure, WHO has updated its Interim Clinical Guidance building on its 2014 publication.

What's new in the 2026 update

The 2026 revision builds on the original clinical guidance and incorporates new scientific evidence, evolving threat profiles, and lessons learned from recent chemical exposure incidents. A rapid systematic review of literature from 2014 to March 2026 confirmed the continued validity of key recommendations while identifying areas for refinement.

Key updates include:

• updated treatment guidance for toxic industrial chemicals such as chlorine and phosgene;
• refined decontamination procedures and terminology;
• updated evidence and references across all sections, aligned with current international best practices; and
• expanded clinical considerations for riot control agents and white phosphorous.

The guidance was updated to ensure applicability in resource-limited and mass casualty settings.

The revision also updates clinical algorithms, symptom tables, and treatment protocols while maintaining the user-friendly structure of the 2014 document.

Supporting frontline health-care workers

The guidance is intended for health-care workers who may receive chemically exposed patients in emergency departments, hospitals, and other facilities, including situations where prior decontamination has not been performed. A core principle reaffirmed in the guidance is the prioritization of lifesaving care: 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.

Developed through expert consultation

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 according to WHO policy, with no financial conflicts identified.

Access and use

The 2026 guidance is published as 'interim guidance', reflecting the evolving nature of chemical threats and medical countermeasures. It is available for open access under a Creative Commons license to support broad dissemination and adaptation.

WHO encourages Member States, emergency services, and training institutions to use this updated guidance to strengthen national preparedness, clinical protocols, and training programmes for chemical exposure incidents.

Acknowledgement:

The World Health Organization gratefully acknowledges the financial support provided by Canada's Weapons Threat Reduction Program (WTRP) for the development of all the WHO products listed above, including the core technical contents of this interim guidance.