Hazardous Gas Releases & Evacuation
A gas leak at a plant, water treatment facility, refrigeration system or truck can spread in minutes. Chlorine, ammonia, hydrogen sulfide, propane and other gases can poison, burn or explode. Quick action depends on warnings, knowing which way to go and not trying to be a hero.
- Plant & Refinery Workers
- Water Plant Operators
- Warehouse & Cold Storage Workers
- Supervisors
- Emergency Coordinators
Recognizing a release
- Alarms: gas detector alarms, horns, strobes or PA announcements. Learn your site's signals.
- Signs: a smell (rotten eggs, ammonia, bleach or rotten onion for chemicals added to natural gas), hissing, a visible cloud or frost, dead vegetation, burning eyes, nose or throat, cough, dizziness or nausea.
- Don't rely on smell. Some gases such as hydrogen sulfide dull your sense of smell, and others like carbon monoxide have no odor. See Hydrogen Sulfide and Carbon Monoxide.
- Check the safety data sheet for the gas properties: lighter or heavier than air, flammable, toxic. See Safety Data Sheets.
What to do
- Alert others and sound the alarm. Use the emergency alarm, pull the station or call the emergency number.
- Stop work, shut down equipment only if it is safe and part of your job. Do not stay to finish a task.
- Move away from the release, upwind or crosswind, using the wind socks, flags or ribbons. Gases drift with the wind. Go to the assembly point or a safe area uphill if the gas is heavier than air (like chlorine), and avoid low spots, pits and trenches where heavy gas collects.
- Hold your breath or cover your nose and mouth with a cloth if you must pass through, and don't run through a dense cloud.
- Don't go back for belongings. Help people who need assistance only if you can do so safely.
- Account for everyone at the assembly point with a headcount and report anyone missing to responders. See Evacuation Headcounts.
- Call 911 and give the location, the gas if known, wind direction, injuries and number of people. See Calling 911 & Giving Your Location.
- Wait for trained responders. Do not enter the area unless you are a trained emergency responder with proper equipment. See HAZWOPER.
Evacuate or shelter in place?
- Evacuate if the release is inside the building or nearby and you can leave safely away from the cloud, as your plan directs.
- Shelter in place when a release outside would endanger you if you leave: go indoors, close doors and windows, turn off ventilation and air handlers, seal gaps, and move to an interior room above ground (for heavy gases, upper floors). Follow responders' instructions. See Shelter in Place.
- Plans must say who decides and how people will be told. Know the plan before an emergency.
Exposed people
- Move them to fresh air, remove contaminated clothing, flush eyes and skin with water, and give first aid. Call 911 and Poison Control at 1-800-222-1222. See Smoke & Chemical Inhalation Injuries and Chemical Exposure First Aid.
- Watch for delayed lung effects and get medical evaluation.
Preparing
- Employers need an emergency action plan with alarms, evacuation routes, assembly areas, wind indicators, drills and roles. See Emergency Action Plans.
- Install gas detection, alarms, ventilation and automatic shutoffs, and keep eyewash stations and showers. See Gas Detectors.
- Coordinate with neighbors and the fire department, and report releases as required to authorities.
- Train workers on hazards, alarms and what to do, and drill.
Gas release checklist
- I know the alarm signals, the assembly point and the evacuation routes
- I move upwind or crosswind and avoid low spots
- I call 911 and account for everyone
- I don't re-enter or try a rescue without training and equipment
- Anyone exposed gets medical evaluation
Standards & references
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