Hazardous Materials Release

Chemicals are found everywhere and are often used in many ways to help better our lives. However, some chemicals can also be hazardous to humans or the environment if released improperly. 

Chemical agents are poisonous vapors, aerosols, liquids and solids that have toxic effects on people, animals or plants. Hazardous materials can include explosives, flammable and combustible substances, poisons and radioactive materials. 

Emergencies can happen during production, storage, transportation, use or disposal. Chemical manufacturers are one source of hazardous material, but there are many others, including service stations, hospitals, and hazardous materials waste sites.

You are at risk when chemicals are used unsafely or released in harmful amounts where you live, work or play. You could be exposed to a chemical by breathing it in, swallowing contaminated consumables, or coming into physical contact with the chemical.

Haz Mat incidents occur when chemical agents are released improperly.


Protect yourself from a hazardous materials incident:

  • Build an emergency kit with the addition of plastic sheeting, duct tape, and scissors.
  • Make a family emergency plan.
  • Know how to operate your home’s ventilation system.
  • Identify an above-ground shelter room with as few openings as possible in case you need to shelter in place.

Take these precautions to help you avoid many chemical emergencies:

Avoid mixing chemicals, even common household products.

Store chemical products properly. Keep products containing hazardous materials in their original containers and never remove the labels unless the container is corroding.

Clean up any spills immediately with some rags, being careful to protect your eyes and skin.

Dispose of unused chemicals properly. Improper disposal can result in harm to yourself or members of your family, accidentally contaminate our local water supply, or harm other people or wildlife.

Many communities have Local Emergency Planning Committees (LEPCs) who are responsible for collecting information about hazardous materials in the community and planning, which is available to the public upon request.

Stay Alert

During a Hazardous Materials Release

If you are:


Asked to evacuate

  • Do so immediately.
  • Stay tuned to the radio or television for information on evacuation routes, temporary shelters and procedures.
  • If you have time, minimize contamination in the house by closing all windows, shutting all vents and turning off attic fans.
  • Take pre-assembled disaster supplies.
  • Remember to help your neighbors who may require special assistance — infants, elderly people and people with access and functional needs.

Caught Outside

  • Stay upstream, uphill and upwind. In general, try to go at least a half mile (usually 8-10 city blocks) from the danger area.
  • Do not walk into or touch any spilled liquids, airborne mists or condensed solid chemical deposits. Try not to inhale gases, fumes and smoke. If possible, cover mouth with a cloth or mask while leaving the area.
  • Stay away from accident victims until the hazardous material has been identified.

In a car

  • Stop and seek shelter in a permanent building.
  • If you must remain in your car, keep car windows and vents closed and shut off the air conditioner and heater.

Asked to stay indoors

  • Bring pets inside.
  • Close and lock all exterior doors and windows. Close vents, fireplace dampers and as many interior doors as possible.
  • Turn off air conditioners and ventilation systems, or set ventilation systems to 100 percent recirculation so that no outside air is drawn into the building.
  • If gas or vapors could have entered the building, take shallow breaths through a cloth or a towel.
  • Avoid eating or drinking any food or water that may be contaminated.
  • Go into your pre-selected shelter room.
  • Seal gaps under and around the following areas with wet towels, plastic sheeting, duct tape, wax paper or aluminum foil:
    • Doorways and windows
    • Air conditioning units
    • Bathroom and kitchen exhaust fans
    • Stove and dryer vents with duct tape and plastic sheeting


Alert Systems

Using alert systems is crucial to being informed before and during hazardous material incidents, just as with any other disaster. Our alert systems page has resources for a number of alert options.

Local Risks

Hazardous materials releases in Williamson County

Hazardous materials incidents, primarily related to transportation, occur several times a month in Williamson County. Major events (i.e., those requiring significant evacuations) occur approximately six times per year across the state. Hazmat incidents are one of the types of calls that the Emergency Management Agency responds to the most in the county. 

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