DATA GATHERING at Haz-Mat Incidents

DATA GATHERING at Haz-Mat Incidents


Without an organized, efficient system for gathering information, managing a large-scale haz-mat incident becomes very difficult and in some cases impossible.

Part 2 of a series.

PART ONE of this series (“Operational Decision Making,” Fire Engineering, June 1989) detailed the integrated decision-making process needed to complement the Incident Command System and complete the step-by-step organization necessary for command of a full-scale, wide-range emergency incident. The fundamental breakdown of that process can be remembered by the mnemonic, GEDAPER, which stands for gathering information, estimating the course of the incident, determining strategic goals, assessing tactical options and resources, planning and initiating actions, evaluating the course of action, and reevaluating that course should it become necessary.

Within the context of GEDAPER, the importance of information gathering is obvious, for it is the initial step on which all others—from assessment to reevaluation—are based.

Let’s turn to the specific types of information the incident commander needs to help make an estimate as to the probable course of action during hazardous-chemical incidents. (“Hazardous-chemical incident'” is used to describe any incident involving hazardous materials or hazardous substances.)

Remember that there are different types of data that must be accumulated when gathering information. First, there is physical data: specific information gathered by the senses—primarily sight and hearing but sometimes taste or smell in some cases.

Second, there is technical data: specific information gathered normally from reference sources such as preplans, computer systems, technical advisors, and so on.

Third, there is cognitive information: specific information that comes from the experience, training, and education of the individual. (Author’s note: In the previous article this was included as technical data. Yet, cognitive data deserves separate status and will henceforth be treated as such.)

All three types of data are very closely interconnected; however, it s important that the IC draw these mental categorical lines so that, during an incident, he can thoroughly and most effectively useeach type.


The process of gathering information about a specific incident should normally begin prior to the actual occurrence of the incident. This preincident information is gathered through familiarization with the response district and through preincident planning of specific target hazards, including transportation corridors.

SARA Title III reporting and planning mandates, state and local right-to-know legislation, and programs such as the CAER Chemical Manufacturer’s Program are designed to identify specificlocations and aid in the development of response plans needed by the local response agencies. All responders have a responsibility to be knowledgeable about:


  • the location of such hazards;
  • applicable departmental standard operational procedures (SOPs); and
  • preplan information and procedures.

I am continually amazed to read accounts of incidents in which companies are dispatched to a tire at John Doe Greenhouse or XYZ Chemical Company and the first-due companies go into standard structural fireground operations. The account often reads to the effect of, “It was only after we had three lines in operation and saw purple, green, and blue flames that it became evident that this was not a routinestructural fire.”

Do not underestimate how negative the impact of such actions and situations can be or the potential nightmare with which the IC may now be faced. Because the information-gathering process has been compromised, inappropriate actions are often taken. Not surprising, those inappropriate actions routinely produce counterproductive and dangerous results. Most often these actions threaten life safety (the health and safety of firefighters); render available resources unusable (due to contamination); expand the magnitude of the incident (by spreading contaminants over larger areas); and threaten to escalate environmental impacts. Basically, such operations run counter to the three fundamental priorities: life safety, incident stabilization, and protection of property and the environment.

The importance of conscientious preincident planning and knowledge of first-response area is apparent. It is the fulcrum on which the incident will swing. Will it swing on the positive side, where the IC makes a swift, accurate assessment of the incident and deploys the necessary resources for mitigation, based on the Incident Command System and GEDAPER?


When an incident is dispatched, the information gathering for the specific situation goes into full swing. During this phase of the incident, the focus is primarily on physical data and secondarily on cognitive data. The data gathered is then used to determine specific facts.

The dispatch process should provide some basic factual physical data, such as the location of the incident, the nature of the incident, and, in some cases, its magnitude (received multiple calls reported from across the street, second alarm, etc.). Such specific physical data may also prompt the gathering of cognitive data. For example, “123 Main St., XYZ Chemical Company, a haz-mat incident.” From this physical data, personnel would know that there is the possibility of chemical involvement because of the address (district familiarity) and the name of the company (chemical companies do not bake bread). Additionally, personnel would also know from preplanning the facility that there are toxic chemicals stored and utilized at that location.

During the response, personnel act to gather additional physical data. Is the situation described during the dispatch in agreement with what they are finding? Is there visible smoke or a vapor cloud? Flow large is the affected area (exposures —interior and exterior)? Are there injured persons? Has there been a release of product? Is the release ongoing? Where is the product going? And so on.


If a chemical incident is found to be in progress, additional specific information must be now be gathered. To say that this is no easy task is quite often an understatement. Normally there will be a substantial amount of confusion and it may be quite difficult to make any sense of the mass of data bombarding the IC. Now the IC may encounter a span-ofcontrol problem. This does not refer to the number of individuals, units, and other resources that can be effectively managed by an individual but rather the amount of information that can be managed by an individual.

To help alleviate the span-of-information-control problem, it is often helpful to break the incident into its component parts. In a chemical incident, the three components are the product, the container, and the environment. As is practiced in the ICS, if the IC can handle the gathering of information on these three components, fine. However, if the IC is being taxed by the incident, it may be helpful to assign other individuals to gather information about one or more specific components. In many municipalities, the haz-mat team will at least initially fill this role quite nicely.

At this point the question arises: What types of information must be obtained about the individual incident components? In order to answer that question more fully, it will be helpful to examine each component individually.


Acquiring physical, technical, and cognitive data on the product is necessary. The following discussion will address many of the specific types of data that are needed. None of the specific types are addressed in the necessary order of acquisition.

To more fully understand the specific product information that is needed, it is quite helpful to understand what will be done with the information. Primarily, product information is used to determine the specific primary and secondary hazards associated with the specific product. Remember, all products will have multiple hazards.

For example, a product that is classified as a corrosive will also exhibit the primary hazards associated with the corrosive materials (the ability to destroy living tissue and metals). Furthermore, it will, as a secondary hazard, be toxic, fuming, mildly to explosively water-reactive, and a moderate to strong oxidizer; it will also cause spontaneous combustion to hypergolic ignition, produce explosives when mixed with fuels, and so on. It is vitally important to gather information in order to determine all of the hazards of a given product.

It should be rather obvious why one of the most crucial bits of data that must be gathered is the specific name of the product or products involved in the incident. If the product is not specifically identified, it will be impossible to utilize any technical data sources (including the U.S. DOT Emergency Response Guide) to determine the specific properties, characteristics, and behaviors of the product. It will be impossible to determine flammability, toxicity, density, flash point, solubility, and other important properties of the product involved. If such information is not gathered, the IC is operating in the dark.

Depending on the specific circumstances of the incident, gathering this vital data ranges from very easy to very difficult to almost impossible. Regardless of the ease or difficulty in obtaining this data, it is absolutely imperative that the product be accurately identified. This identity’ should include the specific chemical name of the product, the U.N. identification number, the CAS number, or any other identification tool. All too often, responders are given information that goes something like this: “No problem, this stuff is something like lime.” By saying “something like lime,” the responder has been provided with no information about the product that is involved, only about a product that is not involved.

Once the product has been identified, the IC can gather data about the physical and chemical properties of the product. Physical and chemical properties are behaviors and characteristics that are unique to a given product, whether the product is an element, compound, or mixture.

Physical properties are characteristics and behaviors that can be observed without the product’s interaction with other materials. Many of the physical properties of a material are detectable through the senses. Such physical prop erties include quantity, color, odor, taste, physical state (solid, liquid, gas, plasma) and physical form (particulate, slurry, sludge, gel, paste, etc ). Some other physical properties that are not as readily identified are boiling point, condensation point, freezing point, and melting point, as well as vapor pressure, flash point, solubility, density, specific gravity, vapor density, and so on.


Chemical properties are characteristics and behaviors that can only be observed when the product interacts with other chemicals or energy. Such chemical properties include flammability, ignition temperature, flammable range, polymerization, toxicity, corrosivity, pH, oxidation capability, water reactivity, pyrophoric nature, decomposition conditions, and so on.

Some of the properties of a given product may be readily identifiable during an incident situation and provide physical data, some require cognitive data, and still others must be obtained from some technical data source. In any case, it is vital to obtain specific chemical and physical data about the product involved.

Consider the following situation: The IC arrives on an incident scene and finds a pool of liquid that’s burning. There are victims down in the immediate area. The container has a DOT red flammable liquid label. From the information provided, the IC could infer that the product is flammable and may very well produce toxic vapors. Foam is used to try to extinguish the fire. Upon application of a foam, a violent reaction occurs, generating a massive gas cloud of choking white gases. It turns out that the product is methyltrichlorosilane, which is highly water-reactive, generates hydrogen chloride and phosgene, and is also toxic and reactive.

Obviously, some specific technical information was warranted in the above scenario. Acknowledgment of DOT classification was not enough: a more thorough analysis of the material —an investigation into its primary and secondary properties—was necessary.

It is important to remember that all product data gathered through technical sources is based on the standard conditions of 21 % oxygen and normal atmospheric temperatures and pressures (NTP). Any incident situation that can change any of these “normal conditions” may dramatically influence the product’s properties. Such situations would include the releases of gaseous or liquid oxygen. In either case an oxygen-enriched atmosphere (more than 24% oxygen) may result, thereby radically altering such properties as ignition temperature, flash point, and flammable range.


Physical, technical, and cognitive data must also be gathered for the container involved in the incident. One important difference between gathering information on containers and gathering information on products is the simple fact that there are substantially fewer containers that can be encountered than there are products. Therefore, the list of data needed for the container is somewhat shorter. Additionally, much of the data will fall in the realm of physical and cognitive data, with much less in the realm of technical data.

Some of the specific types of product data that are needed at a hazardousmaterials incident include the following:


  1. physical state and form
  2. solubilities—water or other possible mixtures
  3. state changes-boiling, condensation, freezing, melting points, sublimation
  4. density-most helpful are specific gravity and vapor density
  5. miscellaneous—flash point, viscosity, electrical conductivity, heat conductivity, deliquescence, color (odor and taste can be important but are not recommended properties for which to check)


  1. flammability—ignition temperature, pyro— phorisis (spontaneous ignition on contact with air), flammable range (upper and lower explosive limits)
  2. toxicity—IDLH, STEL, TLV, routes of exposure, degree of toxicity, target tissues, environmental toxicity (biologic oxygen demand BOD; toxicity to plants and animals), etiologic (biologic hazard), carcinogenicity (ability to cause cancer), teratogenicity (ability to cause birth defects)
  3. reactivity-pyrophorisis, polymerization, spontaneous decomposition, spontaneous detonation, slow oxidation, hypergolic ignition, radioactivity
  4. energy sensitivity-thermal, pressure, photo, electrostatic, shock or impact liability; autopressurization; spontaneous polymerization

A thorough grasp of cognitive data with respect to containers is vital. Responders should be as familiar as possible with the different containers they may encounter. It is extremely helpful to be able to recognize and understand what an MC 307 specification tank trailer or a DOT 103 class rail tank car is. The exact identification of the container will provide specific information as to its possible configurations, strengths, weaknesses, and problem areas. Without this basic cognitive knowledge, it becomes very difficult to gain specific vital information.

Some of the most readily available physical data about the container involves its basic physical characteristics. Such characteristics—size, shape, and configuration —may seem self-explanatory but are vital nonetheless. Such data can be utilized to estimate product capacity, internal pressure, types of product, and so forth. Determination of whether the container is a shipping or storage container (bottles, drums, bags, etc.), a transportation vehicle (highway vehicle, rail car, barge, etc.), or a fixed storage installation (underground or aboveground) has a large bearing on strategy and tactics.

Container identification is not as simple as it may seem. There are several different parameters that are utilized to determine the type of container.

Composition. What is the container made of? There is a tremendous degree of diversity in container composition. Containers may be constructed of paper, cardboard, wood, glass, plastic, aluminum, steel, stainless steel, carbon steel, and many other materials. This information can help to identify specific products involved. The composition will affect the way the containers may react to adverse conditions present as the result of the incident situation. For example, a relatively thin-walled aluminum container will tend to melt rather than explosively fail when exposed to fire.


Designed working pressure. Normally, container pressure ratings fall into four categories (it is important to be aware that different sources may use pressure groupings that differ from the ones listed here): Atmospheric containers will have normal internal pressures that range from 0 psi to a maximum of 5 psi. Low-pressure containers will range from 5 psi to 100 psi. High-pressure containers will range from 100 psi to about 3,000 psi. Finally, the Ultra-highpressure containers will range from 3,000 psi to over 6,000 psi. (All pressures are gauge.)

Complexity. There are two container types with regard to complexity: simple and complex. In a simple container, the shell within which the product is contained is the only integral stuctural component of the container. Simple containers may have multiple walls, such as are found in an insulated MC 307, but the outer wall simply acts to hold insulation in place. In a complex container, there will be at least two walls, both of which are integral to the integrity of the container. A cryogenic containers is an example of a complex container.

Location of container failure or anticipated failure. There are five locations where a container may fail: the wall, openings, valving, piping, and relief devices. The exact location of the failure can be critical in estimating the probable behavior of the container.

Degree to which failure has occurred. For any of the locations where failure may occur, the degree may vary tremendously, from slight to partial to total or total catastrophic. In any case, the degree of failure can have profound impacts on possible options to be utilized during the incident.

Overall stability. It should be rather obvious that the location of the failure and the degree of failure must be considered in the determination of container stability. The physical attitude and location of the container as well as its shape can also be critical. Furthermore, it is important to remember that the stability of the container may change dramatically as the incident proceeds. Depending on the specific conditions, such as flame or radiant heat exposure, or the continued release of product, the container may rapidly destabilize.

Causative agent of the failure. What has caused the problem in the first place? For example, consider a container of corrosive liquid. If the failure was caused by some traumatic situation (impact, dropping, puncturing, etc.), there will be a different set of considerations than with to failure caused by corrosion of the container.


The final chemical-incident component that must be considered is the environment. In this discussion, the term “environment” is used in its broadest sense —as anything or anyone that has been or may be affected by the specific incident situation.

There are potentially a large number of things to consider when addressing environment. For our purposes, however, let’s consider five broad subjects:

• The first consideration is the medium or media into which the product has been released or threatens to be released. There are four basic media into or onto which a product can be released: air, water, surface, and subsurface. Air and water explain themselves. However, it is helpful to examine surface and subsurface media in a little more detail.

Surface releases are those that occur when a product is released onto a solid material. Surfaces include blacktop, macadam, concrete, gravel, soil, flooring, a lab table, and so on. One key factor about surfaces is their relative absorbency. Surfaces that are more absorbent will pose a different set of problems than those that are nonabsorbent.

Subsurface releases are those that occur underground. Most common subsurface releases occur from pipelines or distribution systems or from underground storage tanks. In this situation, product is released directly into the soil. Product that has entered a storm or sanitary sewer system is not a subsurface release, because the product has not been released directly into the soil.

• Exposures are another critical environmental consideration. The term “exposures” is used here in the broadest sense: They are any structures, persons, animals, biological habitats, ecosystems, geologic structures, or geologic strata that have been or may be affected by the release of product. In other words, all things that can be negatively affected by the incident are considered to be exposures.

Depending on the specific situations encountered during the incident, the identification of possible exposures may be extremely difficult. This is especially true for some biologic or geologic situations.

In the case of biologic exposures, even food materials such as molasses or milk can produce severe environmental impacts due to their high biologic oxygen demand. If these or many other products enter a body of water, they are capable of killing most forms of life found in the water, especially if there is little flow. Microorganisms that attack these products will utilize high amounts of oxygen. Enough oxygen can be used up by these microorganisms that water life forms will be asphyxiated.

In the case of geologic exposures, groundwater contamination is an everpresent potential. One key factor that must be considered is the proximity of the groundwater level to the surface. Another factor is the porosity of the soil. If the groundwater level is close to the surface or the soils are very porous, groundwater contamination must be considered with almost any spill situation.

• Meteorologic conditions have a tremendous impact on the management of any incident. Wind speed, wind direction, temperature, humidity, and barometric pressure must be considered. Wind may aid or hinder an operation. Too much wind can blow fine powders and dusts over an extensive area, while too little wind will not help disperse a vapor cloud. Increased temperatures will increase the reactivity of product as well as the internal pressures found in closed containers. High humidity may cause water-reactive products to decompose.

• Topography (the geologic lay of the land) will play a major role in all aspects of the operation. Topography may be a great ally or a great enemy. It will help to determine the overall scene set-up, the location of access points, decontamination zones, command posts, even the overall size of the operational zones. Topography will determine which way and how rapidly a spill will flow.

• Finally, the degree of confinement of the media into which the product has been released must be considered. One of the first considerations regarding degree of confinement is whether the incident has occurred within a confined space (container, storm sewer, room, structure) or outdoors. Are there any conduits, such as drainage swales or pipes, that will act to speed the spread of product, or are there any existing confinement measures that have been taken to minimize product spread? Probably the most familiar type of builtin confinement is the dike systems that surround aboveground storage tanks. Other types of confinements include retention ponds or tanks and the like.

As data about the product, container, and environment are gathered, they must be stored for use during the incident. Ideally, the data will be written down to provide a hard copy for operating personnel to use and double-check. It is also very helpful to identify the sources of technical data in case they must be reexamined. Additionally, writing down the data and sources can be an extremely useful tool in the documentation process after the incident has been completed.

At this point you may be saying to yourself, “Great, I have gathered all of his information—now what do 1 do with it?”

Next month, well address some of the ways to utilize gathered information in order to estimate the course of the incident and determine strategic goals.

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