Smoke & Chemical Inhalation Injuries

Breathing smoke, fumes, vapors or gas can injure the airway and lungs, and can poison the body. Fire smoke may contain carbon monoxide and cyanide, and chemical gases can burn airways. Some effects show up hours later. Anyone who inhaled a significant amount of smoke or toxic gas needs medical attention, even if they seem fine.

• Firefighters & First Responders
• Industrial & Welding Workers
• Cleaners
• Everyone

Common causes

• Fire smoke in buildings, vehicles, wildfires and burning materials. See Wildfires and Wildfire Smoke.
• Carbon monoxide from engines, heaters and generators. See Carbon Monoxide.
• Chemical gases and vapors: chlorine, ammonia, hydrogen sulfide, acids, solvents and welding fumes. See Chlorine and Hydrogen Sulfide.
• Mixing cleaning products such as bleach and ammonia. See Household Chemicals.
• Low-oxygen atmospheres in tanks and enclosed spaces. See Oxygen-Deficient & Enriched Atmospheres and Confined Spaces.

Signs and symptoms

• Airway burns or irritation: coughing, hoarseness, a changing voice, sore throat, noisy or labored breathing, wheezing, singed nose hairs, soot around the nose or mouth, burns on the face or lips.
• Lung effects: shortness of breath, chest pain or tightness, a burning cough, coughing up black or bloody mucus.
• Poisoning signs: headache, dizziness, nausea, confusion, drowsiness, rapid heartbeat, collapse, seizures and loss of consciousness (carbon monoxide and cyanide).
• Skin color can be pale, blue-gray, or, rarely, cherry-red.
• Delayed effects: with some gases, such as chlorine, ammonia, phosgene and nitrogen oxides, fluid can build up in the lungs hours after exposure, even if the person felt okay at first.

What to do

1. Don't become a victim. Do not enter a smoke-filled, gas-filled or unknown space without proper training and breathing equipment. Call 911 and let trained rescuers go in. See Confined Spaces.
2. Get the person to fresh air quickly if you can do it safely, away from the source, and keep them calm and resting. Loosen tight clothing.
3. Call 911 for anyone who has trouble breathing, is confused, has burns on the face, lost consciousness, or inhaled a large amount of smoke or a toxic gas. Also call Poison Control at 1-800-222-1222 in the U.S. for advice. See Calling 911 & Giving Your Location.
4. Check breathing. If the person isn't breathing normally, start CPR and use an AED. See CPR & AED.
5. Give oxygen if you're trained and it's available. Medical oxygen is the main treatment for carbon monoxide poisoning.
6. Keep the person sitting up if that's easier for breathing, or on their side if they are drowsy and might vomit.
7. Remove contaminated clothing and rinse skin and eyes if chemicals got on them. See Chemical Exposure First Aid and Eyewash & Showers.
8. Give the responders the name of the chemical, the safety data sheet, how long the exposure lasted and what symptoms started. See Safety Data Sheets.

Don't

• Don't assume the person is okay because they feel better after fresh air; symptoms can return or worsen later.
• Don't give food, drink or medicine by mouth to someone with breathing problems or confusion, unless a doctor says so.
• Don't use mouth-to-mouth rescue breathing without a barrier on someone exposed to toxic chemicals; use a mask or hands-only CPR as trained.
• Don't smoke or allow open flames near gas or oxygen use.

Follow-up care

• Anyone who had significant smoke or gas exposure should be checked by a doctor, even with mild symptoms. They may need monitoring for several hours, chest X-rays, oxygen levels and carbon monoxide testing, and in some cases hyperbaric oxygen.
• People with asthma, heart or lung disease, older adults and pregnant women are at higher risk. See Occupational Asthma.
• Long-term effects can include reactive airway problems, lung scarring, and memory and mood problems after carbon monoxide. Report any new symptoms.
• Report the incident and investigate: ventilation, detectors, alarms, respiratory protection and procedures. See Incident Investigation and Gas Detectors.
• Report to OSHA when required (hospitalization within 24 hours, fatality within 8 hours). See Recordkeeping & Reporting.

Inhalation injury checklist

• I didn't enter the hazard area without training and equipment
• The person is in fresh air, resting, and 911 and Poison Control were called as needed
• I checked breathing and started CPR if needed
• I removed contaminated clothing and rinsed skin and eyes
• The person gets medical care even if they feel better

Last updated: October 5, 2026