In a situation where a serious hazardous chemical spill has quickly caused a toxic atmosphere, it may be more dangerous to go through those toxic vapors or to attempt to outrun them than to stay in an existing structure.
Shelter-in-Place means to get to the inside of a building and remain there during a chemical emergency rather than attempting to evacuate the area. Shelter-in-Place is a viable option for protection against exposure to potentially dangerous airborne chemicals during an emergency.
How Do You Establish This?
Close all doors to the outside and close and lock all windows (windows sometimes seal better when locked.)
Ventilation systems should be turned off so no outside air is drawn into the structure.
Turn off all heating systems and all air-conditioners and switch inlets to the “closed” position.
Seal any gaps around window type air-conditioners with tape and plastic sheeting, wax paper, or aluminum wrap.
Turn off all the exhaust fans in kitchens, bathrooms and attics, and cover the openings with plastic wrap or plastic sheeting.
Close all fireplace dampers and seal with plastic if possible.
Close as many internal doors as possible in the structure you are in.
Pick a room on the highest level of the structure, as most of the chemicals that are of concern are heavier than air and will settle in the basement.
Select a room in the building that is comfortable and easy to seal off. The room should, if possible, provide access to water, toilet facilities, and have adequate room for people and pets to sit.
If the vapor begins to bother you place a wet cloth over your nose and mouth. For a higher degree of protection, go into the bathroom, close the door and turn on the shower in a strong spray to “wash” the air. Seal any opening to the outside of the bathroom as best you can.
Make sure you have a battery-powered radio and a flashlight in case the power goes out.
Once in the room, seal windows, air vents, and exhaust fans with plastic sheeting and duct tape.
In some homes, light switches and electrical outlets on outside walls are sources of air infiltration and should also be sealed with duct tape and plastic.
Seal around the door with duct tape. If the space under the door is too big to seal with tape, try stuffing a damp towel under the door.
Continue to listen to the radio or TV for emergency information and updates on the incident. Don’t call 9-1-1 unless you have an emergency like a fire or a serious injury.
Keep your phone available in case someone needs to contact you.