Chemical Agents: Facts About Sheltering in Place

What "sheltering in place" means

Some kinds of accidents or attacks may make going outdoors dangerous. Leaving the area might take too long or put people in harm's way. In such a case it may be safer for people to stay indoors than to go outside.

"Sheltering in place" is when people make a shelter out of the place they are in. It is a way for people to make the building as safe as possible to protect themselves until help arrives.

How to prepare to shelter in place

People should choose a room in their house or apartment for their shelter. The best room to use for the shelter is a room with as few windows and doors as possible. A large room, preferably with a water supply, is desirable-something like a master bedroom that is connected to a bathroom. For chemical events, this room should be as high in the structure as possible to avoid vapors (gases) that sink. This guideline is different from the sheltering-in-place technique used in tornadoes and other severe weather, when the shelter should be low in the home.

People might not be at home if the need to shelter in place ever arises, but if they are, it is good to have the following items on hand. (Ideally, all of these items should be kept in that room to save time.)

  • First Aid kit
  • Food and bottled water. One gallon of water per person in plastic bottles as well as ready-to-eat foods that will keep without refrigeration should be stored at the shelter-in-place location. If bottled water no longer is available, water in a toilet tank (not the toilet bowl) is suitable for drinking.
  • Flashlight, battery-powered radio, and extra batteries for both.
  • Duct tape and scissors.
  • Towels and plastic sheeting.
  • A working telephone.

How people will know if they need to shelter in place

  • People will hear from the local police, emergency coordinators, or government on radio and television if they need to shelter in place.
  • .
  • If there is a "code red" or "severe" terror alert, people should pay attention to radio and television broadcasts to know right away whether a shelter-in-place alert is announced for their area.
  • If people are away from their shelter-in-place location when a chemical event occurs, they should follow the instructions of emergency coordinators to find the nearest shelter. If children are at school, they will be sheltered there. Unless instructed to do so, parents should not try to get to the school to bring their children home.

What to do

People should act quickly and follow the instructions of their local emergency coordinators. Every situation can be different, so local emergency coordinators might have special instructions to follow. In general, do the following:

  • Go inside as quickly as possible.
  • If there is time, shut and lock all outside doors and windows. Locking them may provide a tighter seal against the chemical. Turn off the air conditioner or heater. Turn off all fans, too. Close the fireplace damper and any other place that air can come in from the outside.
  • Go in the shelter-in-place room and shut the door.
  • Tape plastic over any windows in the room. Use duct tape around the windows and doors and make an unbroken seal. Use the tape over any vents into the room and seal any electrical outlets or other openings. Sink and toilet drain traps should have water in them (you can use the sink and toilet as you normally would). Push a wet towel up against the crack between the door and the floor to seal it. If it is necessary to drink water, drink the stored water, not water from the tap.
  • Turn on the radio. Keep a telephone close at hand, but don't use it unless there is a serious emergency.

Sheltering in this way should keep people safer than if they are outdoors. They will most likely not be in the shelter for more than a few hours. People should listen to the radio for an announcement indicating that it is safe to leave the shelter.

How people can get more information about sheltering in place

People can contact one of the following:

  • State and local health departments
  • Centers for Disease Control and Prevention Public Response Hotline (CDC)
    • Public Response Hotline (CDC)
      • English (888) 246-2675
      • Español (888) 246-2857
      • TTY (866) 874-2646
    • Emergency Preparedness and Response Web site (
    • E-mail inquiries:
    • Mail inquiries:
      Public Inquiry c/o BPRP
      Bioterrorism Preparedness and Response Planning
      Centers for Disease Control and Prevention
      Mailstop C-18
      1600 Clifton Road
      Atlanta, GA 30333

This fact sheet is based on CDC's best current information. It may be updated as new information becomes available.

This information has been provided with the kind permission of the Centers For Disease Control (

Last Editorial Review: 4/2/2003