Hazard · Air you can't see
Chemical and hazardous-material releases
Some toxic chemicals have no smell. Go upwind, or go in and seal one room — whichever officials say.
Federal steps in this chapter do not change by state. Local orders for Arizona come from Arizona Department of Emergency Management.
6 min read · Updated October 2026
Signs
Ready.gov lists these signs of a chemical release. Some toxic chemicals have no odor.
- Trouble breathing.
- Eye irritation.
- Loss of coordination.
- Nausea.
- Burning in the nose, throat, and lungs.
- Many dead insects or birds.
Before
- Put duct tape, scissors, and plastic sheeting in your kit.
- Learn how to run your home's ventilation system.
- Pick an above-ground shelter room with as few openings as possible.
- Ask your Local Emergency Planning Committee about chemicals stored in your area.
If told to evacuate
- Go immediately.
- To find a public shelter, text SHELTER plus your ZIP code to 43362.
- Get out of the building without passing through the contaminated area.
If told to stay inside
- Bring pets in.
- Go to an interior room. Close and lock doors and windows. Close vents and fireplace dampers.
- Seal the room with plastic sheeting and duct tape.
- Turn off air conditioners and ventilation, or set them to 100% recirculation.
- Seal gaps with wet towels, plastic, tape, wax paper, or foil.
- If gas may have entered, take shallow breaths through a cloth.
If you're outside
- Move upwind of the source.
- If you're in a car, close the windows and vents and shut off the air conditioner and heater.
After
Don't go outdoors, even to help others, until officials say it's safe.
To decontaminate: remove all clothing. Cut off anything that would be pulled over your head. Bag the clothing. Flush your eyes with water. Wash with soap and water.
Household chemicals: never mix bleach and ammonia. Poison Control: 1-800-222-1222 (Red Cross).
Checklist
Checks stay in this browser.
Sources
Public pages this chapter leans on. They win if anything here is out of date.
- Ready.gov — Hazardous materials
Signs, shelter, decontamination
- Ready.gov — Shelter
Sealing a room
- Red Cross — Chemical emergency
Poison Control, bleach and ammonia
- Red Cross — Terrorism
Above-ground shelter, leave gas on
