RBC Shield, LLC

"The Complete WMD Protection Solution"

"SHELTER-IN-PLACE" OVERVIEW

WHAT IS IT?

Most communities in the United States are vulnerable to radiological, biological or chemical hazardous materials emergency. These types of emergencies can result from accidents or even terrorist incidents that could occur at a wide variety of places including industrial facilities, power plants, government and educational institutions, commercial establishments, and during transport. When these events occur, emergency response officials have two basic tools to protect the threatened public. One is to evacuate the public out of the area affected by the hazardous material release. The other is to request that the public "shelter-in-place," (SIP) that is, go indoors, close up the building and wait for the danger to pass.

EVACUATION

Evacuation has long been used to move the public away from danger. Its goal in hazardous materials emergencies is to avoid or minimize exposure to dangerous substances. When evacuation can be completed before dangerous levels of hazardous materials move into the community, it is the public protective action of choice. This will avoid exposure to the hazardous material completely. It may also be preferable when the leak is large, unpredictable and difficult to control, or when there is a high risk of explosion or flash over. However, as shown in the 2005 pre-hurricane evacuation of Houston, evacuations can take a very long time to complete, particularly in areas with high population density. In addition, attempted evacuation of major metropolitan areas is likely to result in huge segments of the population being exposed to toxic clouds of chemical, biological, or radiological substances.

SIP AS A PUBLIC PROTECTIVE ACTION

As evacuation of major population centers has grown more difficult and more hazardous, shelter-in-place has gained acceptance as a public protection tool. The goal of sheltering-in-place during hazardous materials accidents is to minimize the exposure of the threatened public to the dangerous material. Sheltering-in-place uses a structure and its indoor atmosphere to temporarily separate people from a hazardous outdoor atmosphere. The people will still be in the endangered area, but will be protected by the barrier created by the shelter and the short-term protection of its indoor atmosphere. Over time, small cracks in buildings will allow contaminated air to enter the indoor atmosphere. Some exposure will occur, but if properly undertaken, sheltering-in-place can provide substantial protection from doses high enough to cause injury.

The selection of sheltering-in-place to protect the public may be preferable when the leak is very fast, a migrating toxic vapor cloud could quickly overtake unprotected or evacuating citizens, the material released has a low health hazard, or evacuation would create problems that would outweigh its usefulness. The amount of protection from sheltering-in-place varies with:

  • The time and materials available to persons to establish an ad hoc shelter and their capability to recall SIP sheltering protocols under high stress levels
  • The air-tightness of the building or room
  • The length of time the shelter is exposed to a hazardous plume
  • The volatility of any chemicals in the hazardous plume
  • The intensity or concentration of the hazardous materials
  • The effectiveness of the shielding materials used to construct the shelter

Many Local Emergency Planning Committees (LEPCs) have adopted shelter-in-place as an alternative to evacuation. Depending on the risks posed to the community and degree of public education provided, one of four levels of sheltering may be implemented. The Oak Ridge National Laboratory1 has defined these levels as follows:

  • Normal Sheltering - Closing all doors and windows and turning off all furnaces, air conditioners or other ventilation equipment will reduce the infiltration of hazardous particles.
  • Expedient Sheltering - In addition to normal sheltering, taking simple measures to further reduce infiltration. These are placing plastic sheeting over windows and vents and taping over electrical outlets, around doors and other openings.
  • Enhanced Sheltering - Making modifications to the structure to reduce infiltration. Traditionally, these modifications are steps that are often used in weatherizing homes such as caulking around windows, doors and other places where surfaces meet, using weather stripping and installing storm windows. The RBC Shield®product takes enhanced sheltering to a much higher level than is currently available.
  • Pressurized Sheltering - Using special gas-particulate, filter-blower units to pressurize a sealed room, building or other enclosure with filtered air. The filter-blower produces an outward flow of air through leakage points which prevents contaminated air from entering the shelter. At RBC Shield, LLC we strongly advocate incorporating this principle into every shelter.

Normal and Expedient Sheltering methods are the most commonly recommended sheltering techniques in communities around the country. Publications of the Department of Homeland Security, the CDC, and the Red Cross advocate these two basic sheltering methods in the event a radiological, biological or chemical emergency occurs. Household and businesses are encouraged to be able to have emergency supplies available and to be able to implement basic sheltering quickly by having supplies of plastic sheeting and duct tape readily available. Unfortunately, Normal/Expedient Sheltering provide little protection from radiation associated with "dirty bombs," or radiation releases from nuclear power plants due to an accident or terrorist attack.

Enhanced Sheltering and Pressurized Sheltering are typically not discussed or even mentioned in publications geared toward the general U.S. population or U.S. businesses. The RBC Shield® product provides an affordable means for most families and business to easily construct Enhanced Sheltering and to readily incorporate Pressurized Sheltering into the SIP facility.


Sources/Footnotes

  1. Rogers, G.O., Watson, A.P., Sorenson, J.H., Sharp, R.D. and Carnes, S.A. "Evaluating Protective Actions for Chemical Agent Emergencies (PDF)," ORNL-6615, Oak Ridge National Laboratory, April 1990.