Trainer’s Corner: A haz-mat incident scenario
A haz-mat incident scenario
December 7, 2007 By Ed Brouwer
A hazardous materials incident might be the worst, most dangerous event you may ever attend. We’re not talking about a simple fuel spill here. Before I lay out an example of a haz-mat scenario, we need to review a bit. You need to remember some key points: The failure to use PPE, or using it improperly, may have fatal effects. The best protection for the first responder, above all else, is to use SCBA. Fire fighter turnout gear offers limited protection against some chemicals. As time in the hazard area increases, so does the need for the proper PPE. When dealing with emergency situations, information is needed quickly.
Types of hazards: The acronym TRACEM can be used to identify possible chemical hazards: Thermal, Radiation, Asphyxiation, Chemical, Etiological and Mechanical. Tactical decisions are based on the classification of the hazard.
Categories of health hazards: One of the most commonly used terms relating to health hazards is “carcinogen,” which refers to a material with cancer-causing potential. Fifty-eight out of the estimated 10.8 million chemicals on this earth have been identified as known cancer-causing agents, while there are an additional suspected cancer-causing agents. Fire fighters are exposed to a large number of chemicals, and many of them are known cancer-causing agents. If firefighters wear their SCBA properly, these exposures are unlikely to cause problems.
Exposure routes and rates
The four primary routes of exposure are: respiratory, absorption, ingestion and injection. Firefighters deal more with the first two.
Respiratory: Carbon Monoxide (CO) is the most common chemical asphyxiant. It acts in the bloodstream to reduce oxygen availability. CO affects health at lower concentrations and therefore causes greater concern. Low levels of CO can produce flu or cold-like symptoms such as shortness of breath on mild exertion, moderate headaches and nausea. As the level of CO increases, an individual can experience dizziness, mental confusion, severe headaches, nausea and fainting on mild exertion. High concentrations of CO can result in unconsciousness and death.
Absorption: Because the skin is the body's largest organ, the number of chemicals that are toxic by skin absorption is relatively low, but precautions should nonetheless be taken to minimize contact with them. Many can burn the skin.
Factors that affect the rate of exposure, regardless of the route, are basic items such as temperature, pulse, and respiratory rate.
Protective clothing and BAs
Our SCBA offers a protection factor of 10,000. This means a person wearing SCBA has a survivability rating 10,000 times greater than a person who is not wearing SCBA. The SCBA must be fitted properly to the person and must be a positive-pressure device.
Time in a bottle: The Incident Commander must consider the time it takes to enter the hazard area, the working time, time to leave the area, plus the time needed to be decontaminated and undressed. Many departments use one-hour bottles for haz-mat work.
Certainly we are all aware of the problems with SCBA — the extra weight, lack of visibility, lack of mobility, their contribution to heat stress, etc. These issues are only magnified when used in conjunction with a special haz-mat suit. Therefore, the users of BA and chemical protective clothing need to be medically-cleared to function with this type of PPE.
There are four basic levels of chemical protective clothing, Level A, B, C, and D, with Level A being the highest level of chemical protection.
Level A is a fully encapsulated suit. The requirement to use Level A suits is when a fire fighter is entering an atmosphere above the IDLH (Immediately Dangerous to Life and Health) value and the chemical is toxic by skin absorption. The Level A garment is typically an encapsulated suit with attached gastight gloves and boots. It has inner and outer gloves, hard hat, communication system, cooling system, SCBA, PBI/Nomex coveralls and over-boots.
Most volunteer departments do not have Level A suits (their high cost is the main factor) and therefore will most likely be calling in a regional haz-mat team. It is vital to know your department’s limitations when it comes to haz-mat incidents.
Decontamination: One thing your department could do is learn to set up a decontamination unit. Equipment for “decon” is relatively inexpensive. A child’s swimming pool, several tarps, traffic cones, several pails, liquid soap and a length of 2-1/2” hose are just a few of the easily accessible items you can use. If you are interested in learning more, contact your nearest haz-mat team to see what they recommend you have on hand.
Perhaps the best kept secret weapon for your department is a good set of binoculars and a Canutec Emergency Response Guide. Each apparatus should have these two items in the glove box. Canutec books are free and can be acquired by contacting Transport Canada. (An electronic version is also available on-line at www.tc.gc.ca/canutec/en/guide/guide.htm.)
Turnout gear: There are two basic types, proximity and fire-entry gear. Proximity gear is named for the ability to allow the wearer to get close to the burning liquid, giving protection for temperatures up to 150 degrees C to 200 C.
Fire-entry gear is designed to allow the wearer to enter a fully involved fire area for a period of 30 to 60 seconds over the life of the suit. Fire-entry gear can be used in temperatures ranging up to 1100 degrees C.
When dealing with cryogenics, the responder must wear protective clothing that protects the wearer against very cold temperatures. Responders should take precautions to prevent against cold stress and hypothermia. Wearing clothing in layers can offer some additional protection.
There are four basic limitations to protective clothing and they apply across the board from EMS infection control gear, to firefighter TOG (a measure of thermal resistance), to the fully encapsulated Level A suit. The four major issues are: heat stress*, mobility, visibility and commun-ications problems. (* Heat stress can lead to heat stroke, a condition that is almost always fatal. The progression of heat stress is dependent on the amount of work being performed and the physical ability of the responders. Rescuers should be in good physical condition and must hydrate frequently.)
Your department members should be aware of the signs of heat stress and heat stroke. Set up proper rehab stations when dealing with haz-mat. For more on heat stress and heat stroke, watch for an upcoming article by Aaron Brouwer in Canadian Firefighter & EMS Quarterly.
A haz-mat training scenario
Props needed include a pick-up truck or cargo van, several heavy duty cardboard boxes, three or four 45-gallon drums (empty) with lids, Dangerous Goods placards and several MSDS (Material Safety Data Sheets). Most transportation carriers will be more than happy to give you samples of the placards and copies of the MSDS they use through your district.
The set-up: Before the practice, place placards on the boxes and/or the barrels. Place the appropriate MSDS in the “prop” vehicle. If you want to simulate a spill, fill barrels with water or boxes with flour. Arrange your “prop” vehicle on a side road to simulate a MVI. The cargo (boxes and/or barrels) can be left in the vehicle or strewn out.
Two ways to play the scenario out:
1. Page out (simulate) the department to an MVI at the set-up location. Then just let the incident play itself out.
2. Review all of your hazardous material incident protocols before the scenario.
In either case, take notes as you observe their response. Note times and procedures. Watch how your fire fighters deal with the hazard. If a firefighter would be over come by the spilled hazard in real life, he should be notified of that immediately in the scenario. Now it becomes a rescue operation. Beware, you may have several fire fighters down before the night is through. Better it be at a practice than the real thing.
Possible questions: Was there a proper size-up? Was the Canutec guide referred to?
Were more resources called in? Were safety protocols followed? Was the hazard discovered in a timely and safe manner? Did they find the MSD sheets? Was there a spill? How was it contained?
Was an evacuation required? How was that accomplished? Did the highway need to be blocked? How was that accomplished? Was a haz-mat team called in? Was a decon area set-up?
Objectives. Everyone has a place: The above training scenario should get fire fighters thinking about the way they are required to respond when something happens that puts the public at risk. Everyone has his or her place and everyone has to be trained to know when their work is done and it’s time to hand off the problem to the next team.
We must all know our place – our limitations — or we could end up being part of the problem rather than part of the solution. With a haz-mat incident you can easily become a victim. If you are a victim, you can’t be a rescuer.
You can step this scenario up by connecting with other responding agencies (police, EMS, haz-mat, DOT, etc.) and conduct a full-blown scenario.
Remember that the initial size-up is really about determining the scope of the emergency and the potential risk to the civilian population and ourselves as responders. It’s about knowing when it is time to call in the next team.
Until next time, stay safe out there and remember to train like their lives depend on it — because they do!References: National Institute of Enviromental Health Sciences, National Toxicology Program, Firefighter’s Handbook.
Ed Brouwer is the Fire Chief/Training Officer for Canwest Fire and a member of the Osoyoos (B.C.) Fire Dept. The 18-year veteran of the fire service is also a Fire Warden with Ministry of Forests, a First Responder III instructor/evaluator, Local Assistant to the Fire Commissioner and a fire service motivational speaker and chaplain. E-mail firstname.lastname@example.org .
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