Outdoor Aerosol or Vapor

If a suspected aerosol or vapor release occurs outdoors, alert anyone else in the area and move immediately to an indoor location. Ensure that the windows and doors are closed and that the heating/ventilation/air conditioning (HVAC) system is shut off. Locate a room indoors with minimal openings (ideally, without drop ceilings) and seek refuge until after the plume has passed. Ensure that the shelter room contains a telephone and, ideally, a TV or radio to monitor activities outside. Use a sign or mark the door to the shelter room to indicate that people are sheltering inside. Next, if possible, use duct tape and plastic sheeting to seal all openings to the room, including doorways, windows, electrical and telephone outlets, air vents, etc. If duct tape and plastic are not available, be creative and use what you have available. In an office, plastic garbage bags and transparent tape can be used in an emergency. At home, wet towels can be stuffed under doors and used to plug openings. As a general rule, the better the room is sealed, the less likely an aerosol or vapor will penetrate the room.

In a worst case scenario (when sheltering materials are not available), just being in an enclosed room without the HVAC system operating will still provide a high degree of protection. As demonstrated in the 1994 sarin attack in Matsumoto, Japan, simply being in an enclosed structure with closed windows and doors can dramatically reduce the risk of exposure to an outdoor aerosol or vapor plume. This fact is also reinforced by numerous case studies of hazardous material accidents in the United States.

Once the shelter room is sealed, turn on a radio or TV and monitor activities outside of the building. In the event that evacuation becomes necessary before the area outside is all clear, tape down all sleeves and pant legs and use any available clothing to cover as much exposed skin as possible. If possible, use a towel or thick piece of cloth for expedient respiratory protection. The air filtered by a cloth towel folded into four layers will be 8 times "cleaner" than unfiltered air.*

In most cases, the appropriate response is to remain in the shelter room until authorities declare the area clear or instruct you to exit. While waiting for instructions, watch for any indications that the aerosol or vapor is penetrating the room. If there are indications that the agent is entering the room or if people begin to exhibit symptoms of intoxication, early evacuation may be necessary. If you need to evacuate, use a folded cloth for respiratory protection and move everyone quickly through the hazard area directly to the upwind location of the fire department's decontamination site. The decontamination site can usually be recognized as an area where tents, barrels, hoses, and wash basins are located. There will also most likely be emegency vehicles parked nearby and people working in protective clothing.

Expedient Decontamination

In most Tampa Bay locations, emergency responders will be on-scene and set up for decontaminating exposed people within a reasonable period of time. In most cases, waiting fifteen to thirty minutes for decontamination will not result in severe consequences. However, if emergency responders are delayed for a longer period of time or if people begin exhibiting symptoms of nerve agent exposure as described earlier, it may be necessary to initiate decontamination before emergency responders arrive.

If expedient decontamination is necessary, use a systematic process to ensure that people are decontaminated properly and minimize the spread of contamination on the ground. Starting near the contaminated area, evacuees should strip to at least their undergarments. Discarded clothing should be collected at one location downwind of the decontamination site. Next, exposed people should wash thoroughly with water (ideally, hot, soapy water). In most cases, hot water will not be available. Expedient sources of wash water include water hoses, fire hydrants, fire sprinklers, swimming pools, and outdoor fountains. Swimming pools are particularly ideal, as they contain chlorinated water similar to the hypochlorite solution used by emergency responders for decontamination. If a swimming pool or fountain is used, people should wade and wash inside the pool, exit, and rinse using a separate hose outside of the pool.

When establishing a wash site, pay close attention to drainage. Be sure that contaminated wash water is not running into the "clean" side of the decontamination site. Use caution and ensure that washed evacuees do not become re-contaminated due to run-off from the wash area.

Everyone who passes through the wash site should be collected and monitored until emergency responders arrive. If necessary, people can be temporarily clothed using garbage bags to provide a degree of privacy. Once emergency responders have set up their decontamination site, everyone who was passed through the expedient wash process should be decontaminated again and properly assessed for exposure.

NOTES:

*Though using a folded cloth towel as a breathing filter will provide a degree of respiratory protection, an individual may still be fully exposed to chemical absorption via ocular and cutaneous routes (due to exposed eyes and skin). Expedient protection should only be regarded as an emergency enhancement to aid in evacuation and NEVER as a replacement for proper protective gear for those working in possibly contaminated environments.

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