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Chlorine Dioxide (ClO2)

Quick Reference

What is ClO2?

Yellow-brown gas most commonly used in bleaching processes in pulp mills. High reactivity means it must be produced on site, dissolved in chilled water and stored in very large quantities. Gas is heavier than air, is explosive and highly toxic. Degraded by UV light into Cl2.

Crew Safety

  1. Staging/Perimeter ERG does not contain ClO2 specific isolation distances, use as for Chlorine gas.
    • Small spill: 60 m in all directions, downwind 300 m in the daytime and 1500 m at night.
    • Large spill: Railcar: 1000 m in all directions. Highway truck: 600 m all directions. Greater distance downwind. See ERG Table 3 section for “Chlorine” for specifics.
  2. Additional Resources
    • SCBA and chemical protective clothing is required. Most industrial sites will have an emergency response team. Otherwise, the fire-department is required.
  3. PPE requirements
    • SCBA and chemical protective clothing.
    • After contact in a safe location standard contact precautions are sufficient.
  4. Safely initiating patient contact
    • Patient should be brought to meet paramedics in a safe location. Clothing should be removed and initial decontamination performed prior to contact.

Effect on the Patient

Irritant gas that will primarily effect the eyes, mucous membranes and respiratory tract. Irritation of mucous membranes will cause discomfort and pain. Irritation of airways can lead to significant airway swelling causing compromise. Pulmonary edema may be a delayed effect after exposure.

Patient Decontamination

Remove clothing, avoid pulling clothes over head. Do not transport clothes with the patient. If symptomatic flush skin with high-volume, low-pressure water. If symptomatic flush eyes continuously.

Patient Treatment

  • Ensure adequate decontamination.
  • Anticipate respiratory distress and treat as per BCEHS CPGs.
  • Delayed onset of pulmonary edema possible. Exposed persons should be transported for monitoring.

Safe Transfer of Care

Provided patient was decontaminated no risk of off-gassing or secondary contamination.

Paramedic and Equipment Decontamination

Provided staging and decontamination advice was followed no special cleaning or decontamination of BCEHS personnel or equipment is needed.

Quick Access Resources

DPIC Monograph

No DPIC monograph available

Paramedic Specialist Safety Data Sheet

PS Chemical Response Sheet (PDF)

Emergency Response Guidebook

No ERG available

Revision History

Version Date Changes Author
1.0 2026-05-01 Initial version Clinical Hub