Thursday, October 16, 2008

New RFID Sensors for Plume Monitoring

There is a geeky type article over at RFIDUpdate.Com that security managers and emergency response planners ought to read. It concerns some new technology being developed by GE that will make it easier to track toxic clouds from accidental, or terrorist attack related, chemical releases. It is not quite available yet, but it will allow the deployment of a large number of very-small, passive chemical-detectors that can be queried by a central station to determine the presence of a variety of toxic chemicals.

Tracking Chemical Plumes

One of the major problems that site managers and emergency responders have when dealing with chemical incidents is determining the extent of the contamination. This is especially true when dealing with a toxic gas or low vapor-pressure liquid. Even releases with visible vapor clouds can present hazardous concentrations beyond the visible boundary of the cloud. Current technology consists of placing appropriate chemical detectors down-wind of the release to detect the approaching cloud. While the cost of detectors is coming down, their cost still limits the supply.

This requires incident commanders to make complex decisions about where to place the available detectors. Place them too close together and significant portions of the cloud may bypass the detection array. Place them too far apart and the problem becomes cloud infiltration between the sensors. In either case, inadequate definition of the hazard area may lead to wrong decisions about areas to evacuate or shelter-in-place.

This, of course, assumes that the incident commander has the appropriate chemical detectors available. Where there is a fixed chemical facility with a limited variety of chemicals on site, having the appropriate detectors on hand is more often a budgetary decision. For Hazmat teams responding to transportation incidents, it may be budgetary, but it is more likely to be the luck of the draw.

New Technology 

The ‘battery-free, multi-detection radio-frequency identification (RFID) sensing platform’ being developed by GE will radically change this playing field. First, the ‘battery-free’ aspect of the device will make it cheaper to produce; that’s cheaper than current RFID sensors. Remember current ‘expensive’ RFID sensors are still cheaper that current chemical detectors. 

Second the ‘multi-detection’ portion of the description means that one type ChemDetect RFID (you saw that name here first) will report the presence of multiple chemicals. This will make it easier for hazmat responders to have an appropriate sensor on hand, even for transportation incidents.

 Finally, the small size of the RFID, smaller than a dime, will make them easy to store and transport. This is always an important consideration for hazmat teams. There is only so much room in their vehicles, no matter how large those vehicle continue to get, and there is always more equipment that could be crammed into one, just-in-case.

Pre-Incident Deployment 

Chemical facilities that have toxic chemicals on site could pre-deploy these devices in layers around storage areas and areas where those chemicals are routinely used. They could be automatically queried on a routine schedule, once every minute for example. When a tag reported detecting the toxic chemical an alarm would sound and query schedule would be increased and more remote tags would be included in the schedule.

The results of the scans would be displayed on a facility map using a GIS based program. This would help facility management to quickly define the scope of the release. A slowly spreading cloud is a smaller leak than a quickly spreading cloud. If the detection array was dense enough, it should even be possible to calculate the leak rate.

Visual and auditory warning devices could be deployed around the plant, especially along traffic and escape routes. If the toxic cloud were in or near those routes the GIS system could activate those devices and allow evacuating employees to avoid the chemical hazards. For facilities with the potential for off-site effects from a toxic release the array could be extended to off-site locations. Special emphasis would be placed on large population densities, special needs populations, and schools.

The detection tags would be placed between these areas and the chemical facility, at the boundaries of those areas and within those areas. The local emergency management authorities could be given access to the GIS reports from the detection management system. This would allow them to make informed decisions about issuing shelter-in-place or evacuation orders.

Emergency Response Deployment 

It is not unusual for law enforcement to be the first on scene for a transportation related hazmat incident. Arriving on the scene of an accident involving a placarded truck or railcar, they could deploy a small array of these tags around the vehicle to allow for warning of a developing leak. They would select the appropriate small box of tags from a larger box based on the placards on the vehicle.
Subsequent responders; law enforcement, fire, hazmat, what ever; could expand that initial array with tags that they carry. This would allow them to protect themselves from unhealthy exposure while allowing the incident commander to better define the extent of the problem.

DHS S&T Involvement 

GE is developing the basic technology for these tags. Nothing in the two articles that I have seen says anything about developing the GIS based detection management system (DMS) that I have described. This would be something that DHS S&T should get involved in. It would be important to have a standard system that multiple jurisdictions could use. That way all of the devices deployed by law enforcement (local, state and federal), fire and hazmat personnel could all be queried and reported by all of the DMS controllers on the scene.

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