Focus on Hazmat

Any training officer with significant tenure has wondered about his next classroom session once all the usual topics -- personal protective equipment (PPE), selfcontained breathing apparatus (SCBA), monitoring and detection, communications – have been covered. “What can I do that might generate a little genuine interest?” Our conscientious instructor decides to get rid of the old teaching materials and make a fresh start. Problem is, there is only so much teachable information about these topics. Try as he might, our instructor sooner or later comes to the conclusion that his new lesson plan is just “the same old hash chopped a little finer.” Fortunately he has forgotten two things. Familiarity does breed contempt and skills tend to get “rusty” when not used frequently. Even when exercised regularly, people tend to get lax or “sloppy” about proper techniques. So, like confession, review is good for the soul.

Class make-up also impacts the effectiveness of an instructional unit. Class material is not static. It changes if for no other reason than plain old “father time and mother nature.” Any book is a new book to someone who has not read it before, particularly a class of new hires recently assigned to the Emergency Response Team. Lesson plan revision should be a perpetual process. The technology is constantly evolving to handle hazardous materials newly introduced into the marketplace. New innovations in equipment and methodology are developed to handle them safely. New foam formulations for motor fuel containing ethanol which becomes more miscible with water is an excellent example. Trainers finds himself in the shoes of the young boy trying to explain an unsatisfactory grade in history to his father -- “Gosh, Dad, there is a lot more History to learn now then when you were in school.” While the basics of SCBA remain pretty much the same as 20 years ago, apparatus design has changed. Whistles and vibrators supplant the traditional bell (“audi-alarm”) to notify the wearer of low-air pressure. Headgear has been redesigned to increase comfort and reduce fatigue. Attachment of the regulator to the face piece instead of the wearer’s belt reduces the “dead space” in the hoses. What is taught in the classroom must match what is found on the training ground and emergency scene. If students will be using MSA SCBA do not demonstrate operation using Scott airpacks and vice versa. Whatever is used should be current or at least the same vintage as that the students will use.

“Wisdom is the principal thing,” says Proverbs 4:7. “Therefore get wisdom: and with all thy getting get understanding.” This applies to technology as much as theology. A pitfall of our computer society is that we embrace the idea that one does not have to understand a piece of equipment to properly use it. Despite the sales pitch, more is involved in the operation of instrumentation than simply sticking a probe in a tank and reading the meter. The venerable MSA model 2A Explosimeter illustrates this. It is designed to detect an explosive atmosphere. It is rugged, simple and easy to use. In the hands of a knowledgeable operator, the Explosimeter is very dependable. However, some important things are not in the operator’s manual. For example, explosive atmospheres are not sharply defined. The further away one is from the primary source of the flammable constituent, the lower the concentration is likely to be. Consequently, as one walks toward the “hot” zone, the meter readings will increase gradually until the lower explosive limit is reached. This means 100 percent of the lower explosive limit (LEL), not the percentage of explosive component in the atmosphere. If the operator continues walking toward the source the meter readings will decrease. The operator is likely to misinterpret that the readings as 125 percent. The needle went to 100 percent and then dropped to 25 percent. How is this possible? To understand what the meter is telling us we need to learn the principle upon which this particular apparatus works.

At the heart of the model 2A Explosimeter is a platinum filament enclosed in metal gauze through which an electric current from the battery is passed. The filament is a resistance and therefore heats up as the current passes through it, much like an incandescent lamp. Electrical resistance is a function of temperature. As the filament heats up, resistance increases. The filament is connected to one side of a Wheatstone bridge which includes a potentiometer and an indicating meter. The bridge is balanced when the meter shows zero in “clean” air. As the meter is moved closer to the point of release the concentration of contaminate rises while the concentration of oxygen decreases. On the hot surface of the filament the platinum acts as a catalyst, combining atmospheric oxygen with the flammable contaminate. In essence we have a micro fire contained by the wire mesh which prevents ignition. Concurrent with its electrical resistance, the temperature of the filament rises. This unbalances the Wheatstone bridge and generates a reading on the meter.

Three elements are required for combustion, i.e. fire; heat, fuel and oxy gen. Without all three the fire goes out. If the concentration of flammable contaminate becomes so high that the oxygen is displaced the micro fire will go out and the meter will read zero. Not that the ambient atmosphere is safe for human consumption. This simply means that the fuel concentration is too rich to ignite. Any action such as opening a door may introduce enough oxygen to support ignition. So knowing the basic principles behind the Explosimeter enables a knowledgeable operator to understand the readings and interpret them in a manner consistent with what is actually present. The meter is telling the operator that the atmosphere is unsafe but his technique and understanding of the instrument tells him why it is unsafe. Far too many accidents has resulted from inexperienced or undertrained operators who simply stuck the probe into an environment and read the meter without any idea of what the instrument was really trying to tell them. If an instrument of this type was exposed to a very fuel rich atmosphere it is entirely possible to observe a reading significantly less than 100 percent LEL (Lower Explosive Limit). In an extreme case the reading could even be zero. All that the instrument is telling you is that the atmosphere will not burn. It makes no statement as to why. So the knowledgeable operator will activate his instrument in the safe zone and observe readings as he approaches the contamination. If the reading peaks at 100 percent, then decreases, extreme caution is necessary. In one case despite an operator reporting a very low Explosimeter reading, an explosion occurred when a piece of equipment was activated. When quizzed the operator revealed that to save the batteries he had not turned on the instrument until he was at the point of the leak. Had he observed the proper operating protocol he would have known that he was in a fuel rich area and that any movement by those working nearby would bring in more oxygen and create a flammable condition.

Though more sophisticated, newer instrumentation in use today is little different from the Explosimeter. Understanding of the operating principle behind the equipment is still absolutely essential to gaining reliable data. Data is only as good as the person who collects it. Emergency responses are, by definition, extraordinary and unique occurrences. As improvements in equipment and operating techniques come on line the frequency of emergency response calls decreases -- or at least it is supposed to work that way. This means that the response vehicles and the equipment on board spend an increasing amount of time parked rather than on the job. The need for regular maintenance of that equipment becomes increasingly important. Nothing creates more havoc with a chief’s blood pressure or stimulates more profanity than to have his team arrive at an incident only to find that batteries are dead, or, worse, that the old cells have corroded leaving the equipment inoperable. Perhaps the encapsulating suits have been left folded for so long that cracks have developed in the material. What about pressure in the SCBA tanks? Don’t forget the reserve tanks either. When was the last time that the fire extinguisher was inspected? What about fresh gasoline for the engine driven equipment, i.e. generators and compressors. The maintenance list grows each time a new piece of equipment is added. Maintenance should be a major topic in any response team’s training curriculum. The time spent in performing it can, and should be, a golden opportunity for review of equipment operation, service and maintenance.

Somewhere around the turn of the century the digital camera met up with “PowerPoint.” It was a marriage made in heaven, or so we thought. With just a little imagination an instructor could put together a set of visual aids of a quality never before seen. He could carry it all on a computer disk that would slip into a shirt pocket. At first, the results were dramatic but as more and more presentations were put on PowerPoint redundancy began to have its effect. Remember, familiarity breeds contempt. Students began to complain of “death by PowerPoint.” The complaint was valid in many instances. A well thought out flip chart can be a welcome change of pace. No matter how well made, no PowerPoint visual can supplant the “tactical experience” of a hands on presentation in the classroom. Use PowerPoint to illustrate the parts of the air mask if you wish but afterward allow the trainees to actually examine one. Let them know just how heavy it is, how it feels to breathe in one and what the various valves feel like when they are opened. True familiarity makes for effective operation in the field.

Training sessions are also an ideal place to introduce new equipment and/or protocols. This initial evaluation is absolutely necessary and should be conducted under controlled conditions such as in a classroom or training field setting rather than an actual incident. It adds a bit of variety to the usual training regimen and it will expose any unforeseen “bugs” in the equipment or the operating protocol in time to corrections before being deployed. Did a significant number of students have difficulty operating the valves on the instrument? If so, perhaps we should look at the size and type of operating handle or the gloves the operators were wearing. Did the pump fail at a critical time during the exercise? Was this failure repeated? Was it a hardware problem or perhaps a procedural shortcoming? More work may be needed before this procedure is placed on line. On the good side we found out about it before an injury or major property damage could have resulted. Also, do not forget that humans come in different sizes. Training is the place to determine if the standard face mask will fit that new guy with the long oval mug. And what about his friend, the one who looks like Paul Bunyan’s brother? Is the belt on the SCBA long enough to go around him? Do we have a suit big enough to cover him? Now is the time to find out.

These evaluations give the trainees ownership. They want the project” to succeed, so they put forth every effort to make it work. If it fails then we better know the reason. If the new protocol works well then we will have a trained cadre of operators available to disseminate their skills throughout the local emergency response community. We can deploy the new technique with confidence that it will do what it was intended safely and efficiently.

Trainee evaluation is more than grading papers and assigning scores. It is an assessment of understanding. The evaluation instrument is as much under scrutiny as is the student. If a significant number of students miss question nine we need to determine why this happened. Is the examination question worded in a confusing manner? Did we make a mistake in our presentation and inadvertently give out the wrong information? Is there an error in the operating manual? This issue has become more acute as traffic in hazardous materials has become increasingly global. A sentence that is perfectly clear to an American worker may have an entirely different connotation to a British or German one. Whatever it is an inordinately high number of failures should raise a “red flag.” A conscientious instructor will always make every effort to get to the seat of the problem and correct it immediately.

Knowing and doing are two entirely different things. It is one thing for a trainee to recite the steps in setting up a foam appliance. It is something else entirely when a trainee has to grab hold of the nozzle and do it at night or in failing light. Hazards materials incidents do not always happen during normal working hours or in a nice smooth grassy training field. To be considered adequately trained, a responder must be able to “do it blindfolded” and get it right the first time. Our recycled training module must include an opportunity for the trainees to demonstrate their ability to function under all sorts of adverse operating conditions; this is reality.

If the training session presented includes the elements set forth herein then there is no need to fear that the trainees will be bored. They will realize that what they are trying to master today may make the difference between success and failure when the bell rings tomorrow. Success may well be defined as being able to walk out and do it again next week.