In the event of a noxious gas or other airborn element having the potential to reach and harm you, a method of sheltering and sealing a room is potentially the best resource you'll have for shelter against a threat. Keep in mind this is for short term use only as oxygen will continue to be used up the longer you stay in a sealed room.
The following is extracted from Ready.Gov
Guidelines for Staying Put (Sheltering In Place)
Whether you are at home, work or elsewhere, there may be situations when it's simply best to stay where you are and avoid any uncertainty outside.
There may be circumstances when staying put and creating a barrier between yourself and potentially contaminated air outside, a process known as "sealing the room," is a matter of survival.
Use common sense and available information to assess the situation and determine if there is immediate danger. If you see large amounts of debris in the air, or if local authorities say the air is badly contaminated, you may want to take this kind of action.
The process used to seal the room is considered a temporary protective measure to create a barrier between you and potentially contaminated air outside. It is a type of sheltering in place that requires preplanning.
- Bring your family and pets inside.
- Lock doors, close windows, air vents and fireplace dampers.
- Turn off fans, air conditioning and forced air heating systems.
- Take your emergency supply kit unless you have reason to believe it has been contaminated.
- Go into an interior room with few windows, if possible.
- Seal all windows, doors and air vents with 2-4 mil. thick plastic sheeting and duct tape. Consider measuring and cutting the sheeting in advance to save time.
- Cut the plastic sheeting several inches wider than the openings and label each sheet.
- Duct tape plastic at corners first and then tape down all edges.
- Be prepared to improvise and use what you have on hand to seal gaps so that you create a barrier between yourself and any contamination.
- Local authorities may not immediately be able to provide information on what is happening and what you should do. However, you should watch TV, listen to the radio or check the Internet often for official news and instructions as they become available.
Here is a simplifie diagram on how to seal your room if necessary.
Find additional resources at Greater Spokane Emergency Management