Shelter in place

Shelter in place (also known as a Shelter In-Place Warning SAME code: SPW) is the use of a structure and its indoor atmosphere to temporarily separate individuals from a hazardous outdoor atmosphere.^[1]

Definition

It entails closing all household doors, windows and vents and taking immediate shelter in a readily accessible location that puts as much indoor air and mass between the individual and the hazardous outside air, such as a basement or centrally located medium to small room, and trying to make it as airtight as possible by shutting off all ventilation/HVAC systems and extensively sealing the shelter's doors and windows from all outside air contaminants with damp towels, or if available, plastic sheeting and adhesive tape.^[2] Diagrams of what sheltering in place entails following a chemical, biological, radiological or nuclear (CBRN) threat, and how long it is advised to be done for, is provided by the U.S. Federal Emergency Management Agency-affiliated website Ready.gov.^[3]

Effectiveness

Shelter-in-place effectiveness has been evaluated and experimental results show that proper sealing can make a substantial difference to a normal home shelter, finding it to be at least twice as effective against a host of airborne substances when compared against simply staying inside and not implementing the countermeasure, and in most airborne contaminant cases, it is usually much more effective, depending on the particle size of the substance in question.^[4][5][6] If the occupant's breathing-produced carbon dioxide is the only consumer of oxygen in the room then carbon dioxide levels would not begin to reach dangerous values until 3+ hours had passed, in all likely, 4 family home, scenarios.^[4][7]

In the military, "Shelter-in-Place" is comparable to "buttoning up" and has proved life saving in many instances.^[8]

If an individual finds themselves outside during an emergency that calls for shelter-in-place, then effective but low-tech decontamination is required before entering into the shelter.^[9]

The phrase ("Shelter-in-place") has also erroneously been used, instead of the more accurate lockdown, to describe precautions to be taken by the public when violence has occurred or might occur (particularly in shootings) in the area and the perpetrator is believed to still be in the area but not apprehended. The public in the area is advised to carry out all the same tasks as a typical shelter-in-place but without the key step of sealing the shelter up to prevent outside air from circulating indoors, in this scenario people are simply urged to lockdown — stay indoors and "close, lock and stay away from external doors and windows."^[10][11]

Reasons

In light of active shooter events, and the panic that can ensue, a lockdown alert, although often erroneously issued as "shelter in place", is also being implemented as a response to armed events, such as the 2014 Fort Hood shooting.^[12][13] Similarly a lockdown alert was likewise issued as a "Shelter-in-place" alert by the Massachusetts Emergency Management Agency over the cell phone Wireless Emergency Alerts service for local residents during the manhunt for the Boston Marathon bombings suspects.^[14]

Implementation

Residents of an affected community might be informed that shelter in place is being implemented through the news media, Emergency Alert System, Reverse 911, warning sirens or horns, National Oceanic and Atmospheric Administration weather reports, and announcements from vehicles equipped with public address systems. In the United States, facilities like nuclear power plants are required to be equipped with audio alert systems that can be heard within a 10-mile (16 km) radius.^[2]

Once a shelter in place is called, residents are expected to immediately go indoors, bring all children and animals with them, and to close and lock windows and doors. All ways in which outside materials may enter the shelter area should be eliminated, including closure of fireplace dampers, shutting off ventilation or climate control systems, and prepare an area for pets to eliminate waste that does not require allowing them outside. If told to do so via television or radio, those sheltering should seal their rooms with duct tape and plastic.^[2] Upon reaching shelter, those who were outside for a period of time seeking shelter after the shelter in place was called and who may have been exposed to chemical contaminants should remove all outer clothing, put it in a plastic bag, and wash with warm water.^[9] After an announcement that the shelter in place is over, residents should go outside and open all doors and windows to ventilate the shelter. Similar processes should be followed in cars, workplaces, or schools.^[2]

CO2 build up

Sheltering in place is generally only used for a short period of time, typically a few, around 3, hours, this number is based upon assuming the occupant's breathing-produced carbon dioxide is the only consumer of oxygen in the airtight room, in which case, carbon dioxide levels would not begin to reach dangerous values until 3+ hours had passed, in all likely, 4 family home, scenarios,^[4][15] before room ventilation that must produce a full room air change for the shelter to be deemed "recharged"/ready for another ~3 hours. However if the outdoor hazard persists, the "~3 hour" period can be extended if the occupants have an accurate Carbon dioxide sensor, however as these devices can fail for example during the Soyuz 29 spaceflight, the experiencing of a headache can serve as a symptom to unsafe levels, in this case these headaches signaled the crew that their carbon dioxide detector had failed to alert them to change the air purifiers/carbon dioxide scrubber. Normal CO₂ levels were 8.8 mm Hg; the levels had likely reached 62 mm Hg to cause the headaches.^[16]

If shelter occupants have a CO₂ air concentration sensor and the occupants feel the need to stay within their shelter as long as the room air can safely provide, an accurate sensor can thus be used to squeeze the maximum from what the room has to safely offer. For even longer periods it is necessary that they make some prior preparations before sheltering in place. Being equipped with common drain cleaner that contains sodium hydroxide("caustic soda") — which is an effective carbon dioxide scrubber, and can be employed in an improvised rebreather, along with self-contained oxygen candles or the more common welding Oxygen tanks, are the type of equipment necessary to safely extend the period of Shelter-in-place past the point were respiratory/capnograph CO₂ levels would normally be deemed unsafe. In the case of the latter two oxygen sources, both of which also have the added benefit of producing and maintaining a shelter positive pressure which keeps any shelter leaks, leaking out rather than leaking in, Positive pressure environments are routinely employed in the hospital setting where the biological agents found in normal outside air, and generally harmless, may prove fatal to a weak immunosuppressed individual. In radiological/fallout scenarios, if the shelter is airtight and carbon dioxide and body heat build up is thus a concern, shelter-in-place time can be extended with the aid of a DIY Kearny Air Pump once a room air change is required, the use of which would be preferable to simply opening or unsealing the improvised shelters door.^[17]

It is also important to state that the ~3 hour maximum safe shelter-in-place period is derived from assuming occupants are in a typical sized room and that their respiration is the only producer of CO₂ in the shelter/room, failure to communicate this latter part of the warning to citizens has resulted in deaths. For example in March, 2003, three Israeli residents of Kafr Qassem, a mother and her two sons, died in their sleep after sealing the room in which they were sleeping against potential chemical or biological attack. They had lit a charcoal fire to keep warm, unwittingly following the same preparations in Charcoal-burning suicide.^[18]

Incidents

• On February 28, 1997, the Los Angeles Police Department issued a shelter in place for North Hollywood, Los Angeles, due to the North Hollywood shootout.
• On October 2009, authorities called a shelter in place in Contra Costa County, California, after a teenager committed suicide by mixing chemicals together. Three nearby residents who were affected by the fumes were treated at a hospital, and the shelter in place order was lifted after three hours.^[19]
• On May 9, 2010, a shelter in place warning was issued in San Francisco, California, after a gas leak.^[20]
• On July 11, 2011, a shelter in place warning was issued in Clarksville, Tennessee, after a major gas leak from a pipeline and a gas station nearby. No one in the area was killed or hurt.
• On August 6, 2012, a shelter in place warning was issued in Richmond, California, due to a refinery fire at the Chevron Richmond Refinery.^[21][22]
• On August 7, 2012, a shelter in place warning was falsely issued for Contra Costa County, California, due to an emergency at a Shell oil refinery, which never occurred.^[23]
• On October 29, 2012, a shelter in place warning was issued in Louisville, Kentucky, after a train carrying hazardous chemicals was derailed near Dixie Highway and Katherine Station.^[24]
• On September 16, 2013, a shelter in place warning was issued in Washington, D.C., around the Navy Yard after a shooting in Naval Sea Systems Command HQ^[25] resulted in 13 deaths.
• On October 2, 2013, a shelter in place was issued for Charleston, West Virginia, because of a chemical leak at the Clearon site in nearby South Charleston.
• On September 19, 2014, a shelter in place was issued for Barrett and Price Townships in Monroe County, Pennsylvania, due to the search for Eric Frein, a fugitive on the FBI Ten Most Wanted Fugitives list.
• On April 3, 2015, a shelter in place warning was issued for a two-mile radius of the G.E. Factory due to a large fire with hazardous fumes.

Example of a shelter in place warning

470 
WOUS41 KPHI 201142
SPWPHI
PAC089-201600-

URGENT - IMMEDIATE BROADCAST REQUESTED
SHELTER IN PLACE WARNING
PENNSYLVANIA STATE POLICE
RELAYED BY NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
742 AM EDT SAT SEP 20 2014

THE FOLLOWING MESSAGE IS TRANSMITTED AT THE REQUEST OF THE
PENNSYLVANIA STATE POLICE.

THE PENNSYLVANIA STATE POLICE ARE ASKING ALL RESIDENTS OF BARRETT
AND PRICE TOWNSHIPS IN MONROE COUNTY TO CONTINUE TO SHELTER IN
PLACE.

PLEASE DO NOT GO OUTDOORS AND REMAIN AWAY FROM WINDOWS OR OPENINGS
TO THE OUTSIDE. 

PLEASE STAY TUNED TO MEDIA OUTLETS FOR FURTHER INFORMATION.

$$

$$^[26]

See also

• Duck and Cover
• Evacuation
• Mobile Emergency Alert System
• decontamination
• NBC suit
• Center for Disease Control
• Civil defense
• potassium iodide
• Ex-Rad
• Portable oxygen concentrator

References