Mass Decontamination: Dispelling the Mystery

By Mark Eide and Steve Wood

There are many considerations and objectives involved in the management of large numbers of victims in a chemical weapons of mass destruction (WMD) incident. Many of those revolve around a primary objective, the transportation of the injured victims to a hospital. It is essential to decontaminate victims prior to transportation to stop further injury caused by contaminants, to eliminate the spread of lethal agents, and keep hospitals from closing because of contamination. The effectiveness of mass decontamination at a chemical agent attack will have a huge impact on the success of your operation.

WMD and the HAZ MAT Myth
Much of the mystery surrounding WMD operations comes from the misconception that a WMD incident is “the Mother of all Hazardous Materials Calls” and, as such, it is the prerogative of the hazardous material response teams (HMRT) to handle most aspects of a successful mitigation. The simple truth is that HMRTs do not possess the resources necessary to deal with hundreds or thousands of victims. Nor will the HMRT arrive in time to take the actions necessary to save the lives of patients contaminated with a chemical agent. Even the largest metropolitan departments do not have the hazardous materials resources necessary to address thousands or even hundreds of victims of a chemical attack.

The HMRT is a precious commodity at a WMD incident. The training, equipment, and expense associated with HMRTs have limited their availability. The HMRT should be used to perform those specialized operations that first responders can’t¿entry, detection/identification, technical guidance, nonambulatory victim rescue, and in some cases to render a device safe.

HMRTs require time to set up, suit up, analyze, and deploy. Current hazardous materials standard operating procedures (SOPs) do not lend themselves to rapid action and entry, let alone decontamination. It takes an HMRT approximately 15 minutes per person to perform technical decon-tamination. Hundreds or thousands of panicked victims would quickly overwhelm a technical decontamination operation in a mass casualty scenario. At 15 minutes per person, it would take 1,500 minutes (25 hours) to decontaminate 100 persons.

What Is Mass Decontamination?
Mass decontamination is the coordinated removal of contaminants from large numbers of people. It is performed when the sheer number of people potentially contaminated overwhelms the resources available to decontaminate them. By comparison, technical decontamination is the regimented method used by hazardous materials teams across the nation. It may employ the use of solutions to better clean or neutralize a chemical product while mass decontamination is accomplished with copious amounts of water. For the purposes of this article, emergency decontamination is the initial effort to use appliances at hand to remove contaminants while a more thorough means of decontamination is established, either mass decontamination or technical decontamination.

When to Use Mass Decontamination
Mass decontamination is necessary when vast numbers of people have been potentially contaminated with a harmful or life-threatening substance. Patients’ symptoms, conditions at the scene, and reports from witnesses are all useful in the decision of what action to take. In the event of a chemical nerve agent attack, the lethality of the substance may leave no doubt that patients require decontamination. Mace or pepper sprays may mimic the initial signs and symptoms of a nerve agent; a mustard or vesicant agent my have a delayed onset. Training on the recognition and treatment of the many types of chemical, biological, and nuclear warfare agents is readily available and important to incorporate into any first responder’s training schedule.

If it is a mass casualty scenario and patients at the scene are symptomatic, it is time to begin mass decontamination. At that point, it does not matter what the agent is; it needs to come off. EMS personnel at the scene will treat the patients according to symptoms; they can draw conclusions about the identity of the agent from those symptoms. A mass casualty chemical agent incident can be run without definitive agent identification.

The question of what to do about the runoff created by mass decontamination always arises. The short answer is nothing, until you have the resources available to address it. Because of the potential for huge loss of life represented by a chemical WMD attack, the Environmental Protection Agency (EPA) has stipulated that a priority should be placed on actions that will save lives. Actions to contain the mass decontamination runoff should be addressed, but not at the cost of human lives. This reinforces the importance of setting up your operation uphill of the incident so that any runoff flows back into an area that is already contaminated.

Why Mass Decontamination?
Why is immediate mass decontamination so important at a chemical WMD attack? First, mass decontamination removes lethal contaminants from large numbers of patients, increasing their survivability and reducing the threat of secondary contamination. Second, hospitals will close if patients of a chemical attack contaminate their emergency rooms. Most of the effort of fire and EMS personnel at the scene of a mass casualty incident is aimed at moving patients to a hospital. If hospitals close because of contamination, the on-scene effort is pointless because there is nowhere to take the patients. Finally, mass decontamination simplifies operations by placing the responsibility of the incident in the hands of first responders rather than hazardous materials technicians, freeing the hazardous materials teams to take more definitive action.

Chemical warfare agents were developed by many of the brightest minds to one end¿they were concocted for dissemination over a large area for the sole purpose of killing as many of the enemy as possible. They are extremely lethal and persistent. Victims of a true chemical WMD agent release require immediate decontamination and treatment if they are to survive. The resources immediately available are fire companies and those companies that have the equipment necessary to greatly impact patient survivability.

Most of the fire and EMS effort is being expended toward the triage, treatment, and transport of victims to hospitals. Fire and EMS units do not have the capacity to establish long-term definitive care in the field. The transportation of contaminated victims will close receiving facilities and derail the rescue effort aimed at getting victims off the scene. As facilities in the immediate area close because of contamination and overcrowding, victims will stack up at the scene. Victims awaiting transport will require treatment, and personnel will be siphoned away from other aspects of the operation to provide the additional treatment. Policies mandating the decontamination of patients prior to transport are imperative.

Mass decontamination simplifies operations at a chemical incident. Operations at the scene of a chemical WMD incident are challenging because they combine a mass casualty incident with a lethal hazardous materials incident. Mass decontamination changes the complexion of the high-casualty, technically taxing hazardous material incident to a simpler multicasualty operation from the standpoint of EMS. Fire and EMS agencies have more experience in mass casualty incidents than in WMD attacks. Mass decontamination by first responders is a crucial piece of the WMD operations puzzle.

Responsible and effective mass decontamination policies can be developed using normal operating equipment and a minimum of “mysterious” high-tech specialty equipment.

The Mass Decontamination Process
Once the incident is recognized as a mass casualty chemical WMD attack, fire companies can take initial definitive actions to save lives and help forestall the effects of a chemical agent. A regionally standardized approach is an essential element to success. If a WMD agent is successfully released at a crowded venue, few agencies across the nation will be able to handle the response on their own. Mutual aid is a foregone conclusion, and the ability of the differing agencies to dovetail their response efforts will save lives.

The following method is a “no frills” approach that any fire department with an engine company can use. It does not require additional, specialized equipment and is easily adaptable to a hundred or a thousand patients. This mass decontamination method involves two engine companies placed parallel to one another 12 to 16 feet apart. The engineer panels face toward the outside. One engine will face toward the incident while the other faces to the rear. This forms a mass decontamination corridor. More corridors can be created depending on the needs of the incident¿for instance, a male, female, and family mass decontamination corridor.

Initial actions will include setup, size-up, isolation, the request for additional resources, and communications with the victims. All responders should wear full personal protective clothing (PPE) and the operation is set up upwind, uphill, and upstream of the event. A good size-up will inform resources of your findings, location, and approach routes. As first responders begin to take control of the scene and as more resources arrive, the mass decontamination corridor is assembled. While that is occurring, responders can use hoselines or other makeshift aids (such as automatic sprinkler systems) to begin emergency decontamination.

Communication with victims at the scene of a chemical attack is essential. During the Tokyo sarin subway attack, more than 85% of those treated at hospitals fled the scene on their own. Considering that many of those fleeing can be contaminated, their arrival at hospitals can result in hospital closures from contamination. Reassure victims and give them direction. Direct all ambulatory victims to move to a safe refuge area, upwind from the source of contamination and within access of your operation. This removes them from the contaminants and concentrates them in an area to enhance communication and observation. It separates the patients with less severe exposures from those with more serious exposures and helps define the extent of the rescue effort.

To establish the mass decontamination corridor, two engine companies are positioned parallel, the engineer panels on the outside. Then fog nozzles are affixed to outlets on the engines inside the corridor. The nozzles are adjusted to create a wide fog pattern and pumped at sufficient pressure to form a strong shower-like effect, approximately 60 gpm. Firefighters in full PPE then direct the victims to disrobe down to their undergarments. Disrobing is crucial and will remove about 80% of contaminants. Victims then proceed into the mass decontamination corridor. Firefighters direct victims to scrub themselves and monitor the effectiveness of decontamination. Once victims are through the mass decontamination corridor, modesty wear is distributed. Many departments in warmer climates have effectively used large trash bags as modesty wear. The trash bags are inverted and holes are made for head and arms. Trash bags are advantageous–they have many uses and are easy to store in large quantities.

Once decontaminated, the victims are triaged and moved into the medical branch of the operation. Through triage, patients are sorted according to the severity of their injuries and moved to the appropriate treatment area to await transportation to a hospital. Patients triaged as immediate receive priority transportation over those that are minor or delayed. If not injured or symptomatic, patients can be moved to a shelter for further evaluation.

Mass Decontamination Considerations
Your engine company arrives on the scene of a suspicious mass casualty incident and notices a large number of dead or dying animals on the street and sidewalk, unusual vapor clouds, or an unexplained high number of casualties. You recognize this to be a potential mass casualty chemical WMD attack. You can now take initial definitive actions to save lives and help forestall the effects of the chemical agent.

Look to develop a plan to deal with victims and a location that is capable of addressing triage, mass decontamination, and treatment considerations. Communication with victims is essential; direct them to assemble in a refuge area away from the source of contamination. Remember to request adequate resources such as additional companies, hazardous materials teams, EMS, Metropolitan Medical Response Task Forces (MMRTF), and law enforcement. Identify a safe response route, wind direction, and a staging area. Take a general look around the area for suspicious sites that might hide a potential secondary device.

Look at the signs and symptoms the victims exhibit to determine a general classification of the product such as a nerve, blister, or choking agent. Are you and your personnel adequately protected with appropriate personal protective equipment (PPE)? Have you set up a safe distance away? Will you need to administer Mark 1 Auto-Injectors or begin emergency decontamination protocols? Have you requested law enforcement assistance to protect victims and rescuers?

Establish a decontamination corridor as discussed above. Firefighters in full PPE should then direct the victims to remove their clothing (thus removing 80% of contaminants) and proceed through the mass decontamination process. Victims should be directed to scrub themselves from one to three minutes, and firefighters should evaluate the effectiveness of decontamination. Once the victims have been properly decontaminated, modesty wear should be distributed. All victims must be retriaged and moved into the mass casualty treatment or shelter operation.

Managing a mass casualty chemical WMD incident will be mentally and physically challenging, even for the incident commander. Has the command post been located in a safe and secure location? You may use preplans, playbooks, the Emergency Response Guidebook, or other agency specific reference guides or tools. Evaluate the resources requested to determine if they will be adequate to deal with the incident, the crime scene, and the victims. Notify hospitals, key government health or medical officials, FBI, Terrorism Early Warning Group, OES, any mutual aid resources, and any specific agency notifications and alerts. The Incident Action Plan must begin to take shape, using the incident command system to address consequence management. Timely and continuous situation and resource status reports to the IC provide critical planning and intelligence information needed to mitigate this event in a safe and efficient manner.

First responders must review their procedures and then practice and prepare in the event they may be called to handle a chemical WMD terrorist incident. Refer to the attached visor card and Mark 1 Auto Inject Protocol Guide. Consult with your department’s training officer, domestic preparedness corridor, MMRS project officer, and agency medical director to adapt these guides to your future needs for mass decontamination, antidote administration, and evaluating initial actions at a potential WMD scene.

Mark Eide is a captain and a 16-year veteran of the Santa Ana (CA) Fire Department. He has a background in EMS, technical rescue, and emergency management. Currently, he is Santa Ana’s Metropolitan Medical Response System (MMRS) project administrator and is a hazardous materials specialist.

Steve Wood is a captain and a 19-year veteran of the Glendale (CA) Fire Department with an extensive background in special operations. He currently serves as the MMRS project officer for the City of Glendale.

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