“GEDAPER” FOR HAZ MATS -THE FINAL STEPS
DISASTER MANAGEMENT
The conclusion of a six-part series on chemical incident management.
LAST MONTH WE BEGAN the discussion of tactical objectives and methods for chemical incidents. In this, the final article in the series, well continue that discussion and conclude with the final three steps in the GEDAPER system of incident management: implementing the plan of action; evaluating the effectiveness of the plan; and reevaluating, should it be necessary.
LEAK CONTROL
Leak control requires methods of controlling the release of a product from its intended location (container). Most means of accomplishing this goal can be classified as either direct or indirect methods. Direct methods involve direct intervention at the breach in the container through which the product has escaped; indirect methods involve some method of preventing the product from reaching the breach.
DIRECT METHODS
There are four direct methods of controlling leaks: plugging, patching, overpacking, and crimping. These activities place entry personnel at potentially extreme risk due to their direct proximity to the container and the almost 100 percent probability of contamination. Furthermore, the overall effectiveness of these activities is questionable at best in many situations.
In most instances, even when leaks involve containers with products at low pressure (5 to 100 psi), the ability to plug or patch becomes questionable and potentially more dangerous. Pressures as low as 25 to 30 psi have been known to inject fine streams of solids (powders), liquids, or gases directly through the skin in the same fashion as immunization guns. There have been many documented incidents in which paint sprayers were cleaning the gun, held a rag over the nozzle, and injected solvent though the rag and into their hands. The same type of injection is possible through chemical-protective clothing.
In addition, there will always be some gases and liquefied gases that escape a pressurized container, the result of the gas decompressing as it moves from the container to the ambient pressure. The cooling can be great enough to lower the temperature of the gas to its condensation point (boiling point), and it can be deadly. It can almost instantaneously produce severe cryogenic burns to exposed tissue and can embrittle personal protective equipment, including SCBAs, boots, and chemical gloves and suits, leading to their complete failure.
In most cases plugging and patching a breach of any size becomes questionable at pressures of 20 to 40 psi. For small breaches, plugging and patching may be effective at somewhat higher pressures. In a few instances, chemicals at much higher pressures can be addressed when specially designed kits are available for a specific chemical (Chlorine A, B, and C kits, for example). Unfortunately, very few specific container kits are available.
Another major problem with plugging and patching is the type of breach. Very commonly the breach is the result of impact or corrosion of the container. Impacts often result in irregular, awkwardly located breaches. Such situations often make plugging or patching impossible. Corrosion-induced breaches are frequently accompanied by severe thinning of the surrounding area. Such situations can be even more problematic because the use of plugs or patches may simply act to increase the size of the breach.
Plugging involves the insertion of some device into a breach. The device may be tapered or equipped with some method of expanding in order to fill the breach. Commonly we find devices such as plumbers’ plugs, golf tees, wooden or plastic plugs, and inflatable bags utilized for this purpose. Such devices have tremendous limitations in situations where there is not a clean break or where the escaping substance is at atmospheric or low pressure.
Patching involves the placement of some material over the breach. In almost all cases, there must be some method of encircling the container with clamps, straps, chains, bands, or other such securing device. Encircling may not be a problem when dealing with storage containers or piping. However, in situations involving impact and rollovers, encircling is often impossible. When was the last time you responded to a leaking tank truck that was on its wheels?
Overpacking involves the placement of a leaking container inside an overpack container. Most commonly, such situations involve the use of drums ranging from five-gallon to 85-gallon capacity. Most manufacturers state that the leaker should be plugged and/or patched prior to its placement into the overpack. Steps should be taken to determine if the overpack is compatible with the product involved. Most manufacturers recommend that a plastic liner be placed in the overpack (if it is not a plastic container). Once the leaker is overpacked, it should be braced to prevent movement, and absorbent should be placed in the container.
Very commonly, overpacks are used for leaking 55-gallon drums. Such operations are difficult at best. Remember, a 55-gallon drum may weigh anywhere from about 400 pounds to nearly 1,000 pounds. Drums are often stored together very tightly, making access and handling difficult. Usually, a leaker must be turned on end at least once for overpacking. If there is corrosion from the contained product or from the outside, it is very possible for the bottom of the drum to break free from the sides, resulting in the product splashing around at least the immediate area.
Gas cylinder overpacks, commonly called “cylinder coffins,” are a relatively new kind of overpacking used in some areas. The leaking compressed gas cylinder is placed inside the coffin, similar to placing a torpedo into its tube. The end of the coffin is then closed and sealed to contain the gas. These coffins are designed for high-pressure situations. Unfortunately, they are quite large and heavy, and moving them usually requires a pickup truck.
Crimping involves squeezing a leaking pipe so that the walls come together, stopping the flow of product. Most commonly, crimping is used for flexible, small-diameter tubing used in gas or liquid delivery systems, including vehicle fuel lines. Crimping may be accomplished by simply bending the piping back upon itself, or it may require the use of a specially designed device. Hydraulically operated systems are utilized by some industries for the purpose of crimping.
Crimping does have some major drawbacks: First, brittle materials cannot be crimped because they will simply break or shatter. Second, rigid materials are extremely difficult to crimp even with appropriate equipment. Third, the larger the diameter of the pipe, the larger the crimping device must be.
INDIRECT METHODS
Indirect leak control methods involve manipulating the product without manipulating the breach itself. Therefore, in general, indirect methods are substantially safer for the personnel involved in the operation —they usually don’t involve coming into direct contact with the breach and hence the escaping product.
The three primary objectives available for indirect leak control are product transfer, product displacement, and the use of shut-offs. These options, requiring manipulation of product in the container, sometimes by a mechanical device, often must be performed by specially trained, experienced industrial or contracted personnel.
Transfer is the process of removing product from a compromised container and placing it in another suitable container. Important considerations must be scrutinized before undertaking this activity.
- First and foremost, the properties of the product must be identified. Is it flammable, corrosive, oxidizing, toxic? What are the potential impacts of these properties during the transfer?
- Is it appropriate to transfer the product? In some situations, such as the rollover of a loaded, aluminum MC 306, gasoline tank trailer, the vehicle must be off-loaded prior to righting. If the product is not off-loaded, there is a very high probability of structural failure with possible total loss of product. However, a similar type of rollover involving a DOT 103 or 111 specification tank car would normally not require off-loading prior to righting.
- The specific type of transfer mechanism (vacuum unit, pump, pneumatic, gravity, etc.) must be appropriate for the situation and the product. For example, a standard acid transfer pump will not be compatible with all types of acids. Pump impellers have been eaten away by incompatible products. Gaspowered water pumps have been brought to the scene by contractors to transfer gasoline—a potentially lethal idea. Furthermore, especially in cases involving flammable or combustible products, the containers must be properly bonded and if possible grounded to eliminate static electric buildup.
- The methods used to gain entry to the container must be analyzed. The use of a pneumatic hole saw on an aluminum MC 306 transport carrying gasoline is a sound, industry-accepted, stan-
- dard off-load method. On the other hand, the use of such an approach on a stainless MC 307 carrying the same loading would be inappropriate. Removal of a bung with visible crystallization from a leaking 55-gallon drum of isopropyl ether could generate a lethal explosion, while removing the bung from a leaker containing hydrochloric acid would be appropriate.
- Finally, careful scrutiny must be given to the receiving container. The IC must be certain that the container is completely compatible and transportable once the transfer has been accomplished. Receiving containers have failed in the middle of transfer because of incompatibility between the product and the container itself or one of its attachments (valves, flanges, and so forth). Transfers have been completed before it was realized that the container, vehicle, or drum did not meet appropriate requirements and could not be moved.
Displacement is a process whereby a material, usually water or foam, is pumped into a container so that it, not the original product, will escape through the breach. The most common example of such an operation is the placement of water into a leaking vehicle fuel tank; a sufficient volume of water displaces the lighter product higher than the level of the breach. Obviously, such an operation normally will not go on tor an extended period of time and is not the overall solution to the problem. Rather, displacement is a stop-gap technique used to buy time for some other operation.
It s critical that the IC examine the water-solubility and water-reactivity of the product if water or foam is to be used in the operation. Obviously, it would be of little value to use water or foam, even polar solvent foam, if the product were water-soluble. Just as obvious. it could be downright lethal to use foam or water on product that reacts with water.
One specific application of displacement that deserves mention is its use in bulk facility fires involving dike and flange fire or release situations. Foam and water have been very effective when introduced into the piping involved, capable of extinguishing the fire or stopping product release by displacing the product.
The use of shut-offs, just as the name implies, involves closing some type of product flow control device to prevent product from reaching the breach. Why consider plugging, patching, overpacking, and so on if all that was needed was to close the valve? That realization can be painfully simple; yet the act itself can carry great potential danger.
If it is possible to stem the flow of product by safely closing a valve, that’s great. However, understand that closing a valve, especially if it puts the responder in close proximity to the leak, can be deadly. Suppose the breach was caused by an overpressurization of the container. The piping leaving the tank ruptured downstream from the shut-off. Obviously, the pipe was the weakest link in the system. Why did the pipe fail before the relief valve relieved the pressure? The pipe could have been damaged or did not meet specifications for that application. or the relief valve may not be functional, or there may he no relief valve. In any case, if the reason for the original buildup of pressure is still present, shutting the valve will deactivate the present relief device —the broken pipe. When the valve is shut, the pressure would again build until the next weak link fails.
When it has been determined that the closing of a valve is appropriate, remember: Never use force on a valve. Valves and valve stems have been known to fail if pressure is applied. In some instances the stem simply shears off. In other instances the stem can become a highspeed projectile capable of fatally wounding any nearby person. Also, such shearing will usually result in additional release of product.
MISCELLANEOUS METHODS
Venting, flaring, and vent-and-burn are three options for dealing with chemical releases or threatened releases that deserve mention. They’re not ordinary methods and are difficult to classify as either direct or indirect.
Venting is the process of releasing a gas, a liquefied compressed gas, or a volatile liquid in a controlled fashion. Normally such an option would only be utilized with the threat of mechanical failure or explosion of the product container. Since the product will be released to the environment, the IC must consult with representatives of the parties involved and most certainly with state and federal environmental personnel before approval for any such operation is given. Most commonly, such activities do not fall to the responsibility of fire service personnel and should not be carried out by them but rather by contractors of industrial representatives.
Flaring is usually identical to venting except that there is an initial intent to consume the product by burning. Most commonly, flaring involves compressed gases, liquefied compressed gases, or liquids that have a high vapor pressure. Consultation with environmental agencies and industrial and contract personnel is imperative.
Venting and flaring present very real dangers for the personnel involved. In one recent situation, a compressed gas cylinder of a pyrophoric gas (one that spontaneously ignites on contact with air) was contaminated by an oxidizer. The cylinder was transported to a facility where it was determined that the contaminated material would be vented by a contractor. As the venting process was undertaken, “combustion” (explosion) began and propagated through protection devices and back into the cylinder. The cylinder exploded, killing three workers and severely injuring another. The explosion ignited a fire that severely damaged the fire building.
Vent-and-burn is a process in which a shape charge is placed on a container in order to blast a hole in the container. The hole or holes vent off the pressure and release product that is ignited by a preset ignition source. The product is then allowed to burn in a controlled fashion. According to the best information available, vent-and-burn was first tried in Molino, Florida and produced a very spectacular—seemingly nominally controlled —controlled burn. The incident in which vent-and-burn received the widest attention was in Livingston, Louisiana. Three tank cars were subjected to this technique. The first car produced a spectacular release of product and accompanying fireball. The remaining two cars produced a very controlled release and combustion of product.
Again, all three of these techniques are quite out of the ordinary and have the potential to be very high-risk. Authorities must be aware of the definite potential for litigation resulting from these techniques. They should not be attempted by individuals who do not have appropriate expertise and training. In addition, remember that appropriate approval from governmental agencies must be obtained prior to performing such techniques.
FIRE CONTROL
Fire can be one of our most lethal adversaries or one of our greatest allies when it comes to chemical incidents. Remember, it is vital that the tactics utilized for chemical fire situations at least start from a defensive mode of operations. An aggressive offensive attack may be determined appropriate, but only after a thorough evaluation of the situation and the potential impact of such actions has been completed. The IC may have to prove that the actions taken were indeed appropriate and that attacking the problem in fact limited the total loss and did not add to it. The day has come when an IC can be found liable for the environmental cleanup caused by water that was applied to the fire.
If the IC decides to attack the fire, the standard firefighting goals (RECEO VS, etc.) and objectives should normally be applied. Close consideration must be given to the impact of water application on spill and leak control activities. And, of course, the IC must examine the potential life hazards and environmental issues involved.
The methods for applying alternative agents must also be closely scrutinized. Consider a situation in which the IC is faced with a fire in a paint store. Most paint stores are stocked with not only consumer-type paints but also industrial-type paints and solvents, often in large quantities. The application of plain water to fire may simply spread the lighter-than-water flammable liquids throughout the store and into the environment. If the fire’s magnitude is such that an aggressive offensive attack will confine the fire to the area of origin and not spread the burning product to uninvolved areas, then a conventional attack would be appropriate. However, suppose that lacquer, lacquer thinner, mineral spirits, paint thinner, and oil stains are involved. The application of water would quite possibly have little or no extinguishing effect on the burning materials involved, while foam would knock them down in short order.
Remember some general principles regarding fire control: If possible, keep attack personnel from direct contact with products and runoff as best as possible. If there is no way to reduce contact, such as remote application and heavy ventilation, minimize the number of personnel who will be exposed. Set up zones. Once extinguishment has been accomplished, make sure that personnel do not wander all over the scene. They must be decontaminated and their personal protective equipment very often must be contained at the scene. Contaminated apparatus also must be decontaminated at the scene if possible. Overhaul activities are normally not done unless personnel use appropriate levels of personal protection. This applies to fire marshals or other investigators as well.
I do not mean to oversimplify this problem. Indeed, fire involving chemicals is one of the most difficult situations an incident commander can face. He must consider all of the possibilities and not rely on tradition or habit as the only tool available.
PLAN OF ACTION
Once the IC has gathered all available information, estimated the course of the incident, determined strategic goals, and assessed the tactical options and resources needed to meet those strategies, the plan of action has been identified. All that remains is to inform all personnel as to the exact plan. Normally, this process is handled by simple verbal messages and is never written down. However, in a difficult or complicated incident, or one of long duration, it is very helpful to put the plan down in writing. Such written plans may be contained on a checkoff sheet or status sheet or may require the use of specially designed forms, boards, or overlays.
One of the primary reasons for a written plan is simply that command often must be transferred, either up the chain or horizontally. Written plans are extremely helpful in familiarizing the incoming IC of the exact situation and what is being attempted.
As the incident evolves, there will often be a need to modify the plan. When one goal is attained there may well be two new ones to take its place. Consider a large structural fire at which exposure protection and confinement are the initial goals. As the fuel is consumed, the threats to the exposures and of further extension are decreased. At some point in time, extinguishment of the remaining hot spots may become the primary goal. So it is in many situations.
EVALUATION
Once the plan of action has been formulated and undertaken, the IC must evaluate the effectiveness of the plan and the operations designed to accomplish the plan—he must decide if the plan is working. The IC cannot effectively evaluate an operation in a vacuum; he must solicit and receive information and input from the other officers involved. They are the IC’s eyes and ears as to what is occurring at the scene. Unfortunately, all too often the “roving command syndrome” (the IC wandering around the incident scene) takes hold, usually because the IC is facing problems in meeting his strategic goals. Sometimes the problems stem from the IC’s inability to communicate effectively with the other officers, his mistrust of information supplied by his officers, or his inability to manage effectively the information that has been supplied.
Once information has been obtained and the operation’s status continually updated, the IC must determine if the operation is falling within the realm of anticipated variation. If not, he must ask some very difficult questions. Is there a problem with the operation, or is it just taking longer than anticipated? Are the goals wrong? Are the goals right but the tactics wrong? Is some vital information missing or wrong? Is something happening of which no one is aware? Oftentimes these are not easy questions to answer, but they must be addressed nevertheless.
REVIEW OR REEVALUATE
The IC can address the questions raised during the evaluation process by reviewing. He must go back to the beginning of the management decisionmaking process and regather information, develop a new estimate of the probable course of the incident, determine if the original strategic goals are still appropriate, and assess if the tactical options and resources are meeting the goals. The plan of action will have to reflect whatever changes have occurred within the strategic goals and tactical objectives and methods. The IC must then evaluate the effectiveness of the new plan. If the new plan is found to be lacking or a period of time has passed in which strategic goals are not accomplished, the whole process must again be reviewed.
Hopefully, through this series of articles I have been able to present some management decision-making concepts that will be of value to you during emergency operations. I am not trying to say that you must follow the GEDAPER process because it is the answ er to all of your problems. It is one systematic approach to decision making.
It does not matter whether you use the GEDAPER system or some other system. What does matter is that you use some type of system that will provide a methodical, scientific process for the management not only of hazardousmaterials incidents but of any critical incident situation.