Hazardous materials are chemical substances which, if released or misused, can pose a threat to people’s health or the environment. Emergencies can happen during production, storage, transportation, use, or disposal.

You are at risk when chemicals are used unsafely or released in harmful amounts where you live, work, or play. A hazardous material incident can happen anywhere, and you need to be prepared in case an incident occurs near you.

Ammonia is the most common chemical spilled in Wisconsin. Natural gas is the second most common chemical released in the state, followed by hydrochloric acid.

Wisconsin Emergency Management contracts and manages 22 Regional Hazardous Materials Response Teams in the state.

Classes of hazardous materials


Explosives that most people are familiar with include dynamite, gun powder, and fireworks.


These can include ammonia, propane, spray paints, helium, chlorine, or carbon monoxide.

Flammable liquids

Examples include gasoline, acetone, ethanol, and lacquer-based paint.

Flammable solids

Examples include match sticks, Sterno, highway flares, oily rags, or magnesium fire starters.

Oxidizing substances and organic peroxide

Examples include hydrogen peroxide and silver nitrate.

Toxic and Infectious substances

Examples include cyanides, lead compounds, phenol, some pesticides, biological samples, and clinical waste.

Radioactive materials

Examples include medical isotopes, uranium, plutonium, cobalt, and spent nuclear fuel.

Corrosive substances

Examples include sodium hydroxide, hydrochloric acid, or sulfuric acid.

Miscellaneous hazardous materials/dangerous goods and articles

Examples include ammonium-nitrate fertilizers, asbestos, any battery-powered vehicles or equipment, and dry ice.

What to do before, during and after a hazardous materials incident

  • Build an emergency supply kit, with the addition of plastic sheeting and duct tape
  • Make a family emergency plan
  • Know how to operate your home’s ventilation system
  • Identify and above-ground shelter room with as few openings as possible
  • Contact local emergency management office to find out what chemicals are stored in your community. Businesses that store hazardous materials are required to report the quantity and type of material.
  • Get away. You should get away from the area of the chemical release. Once you are away, clean any chemical exposure off your body and get help as soon as you can.
    • If you are inside. Get outside into the fresh air and quickly move as far away as possible. Take any pets with you.
    • If outside. Get away from the chemical release area as far as you can and uphill if possible. Chemicals stay close to the ground.
      • In general, try to go at least a half mile (usually 8-10 city blocks) from the danger area.
      • Do not touch any spilled liquids. If possible, cover mouth with a cloth or mask while leaving the area
      • Stay away from victims until the hazardous material has been identified.
    • Disposing of contaminated clothing. Quickly remove clothing that came into contact with hazardous materials. Cut off clothing rather than pulling it over your head.
      • Put clothes into a plastic bag while avoiding contaminated areas of clothing. Use tongs or other items to handle contaminated clothing.
      • Any item used to dispose of clothing should also be placed inside the bag. Seal the first plastic bag inside a second plastic bag.
      • Alert officials of your contamination bag for proper disposal.
  • Asked to stay indoors. If you are in a building and have not been exposed to the chemical, close all windows and doors. Stay inside. Keep any pets inside with you.
    • Close vents, fireplace dampers, and as many interior doors as possible.
    • Turn off air conditioners and ventilation systems
    • Avoid eating or drinking any food or water that may be contaminated
    • Seal gaps under and around doorways, windows, air conditioning units, exhaust fans, and stove and dryer vents. Use wet towels, plastic sheeting, duct tape, wax paper, or aluminum foil.
  • Asked to evacuate. Do so immediately and stay tuned to the radio or television for information on evacuation routes, temporary shelter locations, and evacuation procedures.
    • If you have time, minimize contamination in the house by closing all windows, shutting all vents, and turning off attic fans.
    • Take your pre-assembled emergency kit
    • Remember to help neighbors that may need special assistance. These can include infants, elderly people, and those with access and functional needs.
  • Listen to local radio or television stations for the latest emergency information.
  • Go to a designated public shelter if you have been told to evacuate or you believe it is unsafe to remain in your home.
  • Follow decontamination instructions from local authorities.
  • Seek medical treatment for unusual symptoms as soon as possible.
  • Place exposed clothing and shoes in tightly sealed containers.
  • Advise anyone who comes in to contact with you that you may have been exposed to a toxic substance.
  • Return home only when authorities say it is safe. Open windows and vents and turn on fans to provide ventilation.
  • Find out from local authorities how to clean up your land and property.
  • Report any lingering vapors or other hazards to your local emergency services office.

Additional Resources

Wisconsin Department of Health Services – Chemical Release Toolkit:

Centers for Disease Control and Prevention – Chemical Emergencies:

U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration: