BY ERIC G. BACHMAN
Every day, emergency services workers are dispatched to incidents of varying natures, and the public expects them to fix whatever the problem is. Often, the person calling 911 provides inaccurate, vague, and even totally incorrect information. This places emergency services personnel at a greater disadvantage, since even the basic information they need to prepare for what they may be encountering is missing.
A key element to responding to any emergency is situational awareness of what will or may happen. Many indicators provide evidence or clues of a problem that exists. For fire events, alarm system activation, sprinkler system water flow, and obvious smoke and fire are indicators of real or potential fire conditions. For incidents involving hazardous materials, the indicators may not be as obvious. Responding to a hazardous materials incident blindly can result in harm to responders. When responding to a potential hazardous materials incident, there are eight clue categories that provide indicators that an actual or potential release exists. The acronym DEADSCUM represents these clue categories.
D = DOCUMENTS
Several documents can indicate what materials may be present. At a transportation emergency, safely obtaining the shipping papers, bill of lading, and manifest or consist will provide detailed information on the hazardous cargo. Any of these documents will reveal how much product is being transported, the name of the product manufacturer, and other contact information that will be key in facilitating a favorable outcome.
The material safety data sheet (MSDS) (photo 1), developed by the product manufacturer, is separated into as many as 16 sections. Each section addresses specific information, including values on the product’s physical and chemical characteristics, how it should be handled in an emergency, and treatment for exposure.
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| (1) A facility MSDS manual. (Photos by author.) |
A third document often provided to fire departments is the Tier II Chemical Inventory Report. This document is required by the Superfund Amendments Reauthorization Act of 1986. A facility with certain inventories of hazardous materials must annually file a report. A copy must be submitted to the fire department having jurisdiction. This document can be a good preincident preparedness and training tool, as it reveals some materials a facility uses, stores, or manufactures. The general hazards of each product are listed, as well as how the material is stored (container type, temperature, and pressure conditions) and where it is stored.
This document has many limitations.1 One limitation is that it covers only materials that meet or exceed certain inventory thresholds. If a product on-site is below the reporting threshold, it does not have to be reported. Therefore, if a department is not aggressive in gathering preincident intelligence and relies solely on the Tier II report for chemical hazards, it may not be well prepared for an incident involving a product used under the reporting threshold. Another limitation is that the report reflects the chemical inventory for the previous calendar year. Therefore, more recent changes in inventory or added chemicals may not be readily known.
Another limitation is that certain facility types are exempted. They include laboratories, government facilities, and certain agricultural establishments. Therefore, just because you do not receive a Tier II report from a facility does not mean it does not house hazardous materials. It may be exempt, or the quantities are below the reporting thresholds.
E = EYEWITNESSES
It is important to interview eyewitnesses to a hazardous materials incident. Key information to ascertain from them includes the following: What did they see? Was the product a solid, liquid, or gas? What was the product doing? If a liquid, was it a standing puddle? Was it flowing down a conduit, and to where? Was it fuming? If a gas, what color was it? Was it staying low to the ground or rapidly rising? If a solid, was it a powder, pellets, or other mass? These are just a few questions to ask. There may be many others, depending on the situation and the product involved. Witnesses may also be able to describe information related to container damage such as scores, punctures, cracks, and so on.
A second interview category would be smell: What did eyewitnesses smell? Ask for specific descriptors. If they report an irritating odor, how did it affect them (the eyes, nose, throat, or other bodily areas)? Can they associate the odor with a specific material? One caution is that some materials may desensitize the olfactory system quickly. Eyewitnesses may report an initial odor that then went away. It may not mean that the product is no longer present but that the product has sensitized their sense of smell.
A third interview element would involve what they heard. They may report a hissing, crackling, or bubbling sound. An explosion could have precipitated the release. Carefully consider each of these eyewitness clues when developing incident strategies and tactics.
A = ASSUME
For all incident responses, assume a hazard exists until it can be verified otherwise. For potential hazardous materials situations, it is prudent to take a defensive posture and assume that a hazmat incident exists until it can be verified or nullified. Rushing into a situation haphazardly can result in an unfavorable outcome, including serious injury or death.
D = DEVICES
This is the second “D,” but it does not indicate a priority order with Documents. Devices include handheld monitoring devices as well as fixed facility detection systems. Many fire departments carry air-monitoring devices to quantify atmospheric conditions. Most departments have carbon monoxide detection capabilities, with more and more using multigas monitors. It is not the intent of this article to interpret monitor readings or prescribe protocols for monitoring; however, you must adhere to several key aspects related to air-monitoring:
1 Know how to use the device properly (photo 2), including how to power it on and off and monitoring procedures. The monitoring process should be methodical, not a haphazard rapid walkthrough of a suspect area. Also, you should be familiar with attachments such as probes, and know that it takes time for the device to process the intake sample; time is essential to recording an accurate reading.
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| (2) A handheld air-monitoring device. |
2 Know how to maintain the monitor. This includes consistent calibration of the device as recommended by the manufacturer and the replacement of seals and other conditional items such as filters. A common misconception has to do with sensor replacement. Monitor sensors have a shelf life regardless of whether the monitor is used or not. Replace sensors in accordance with the manufacturer’s recommendation or as needed by evaluating calibration results for decreasing sensor capabilities.
3 Understand what the monitor is telling you. Sometimes, departments do not have sufficient competency in interpreting the readings, comparing them with known factors, and evaluating them to establish protective actions. What the monitor is telling you is critical to your safety. Recognize the lower explosive limit (LEL). A rule of thumb is that 10 percent of the LEL constitutes an indoor atmosphere that is immediately dangerous to life and health (IDLH) and 20 percent of the LEL indicates an outdoor IDLH area. It is important to have access to resources that provide the characteristics of products. The LEL for gasoline, for example, is 12.5 percent. A responder monitoring gasoline vapors may not recognize that a 1.3 percent LEL is dangerous, since he may perceive it to be well below the LEL and, thus, of little consequence.
Other cautions are necessary for other sensor readings. When comparing monitor results with known values, keep in mind that published exposure data indicate workplace exposures. You must evaluate occupant demographics with the levels because certain groups will not have the same tolerances as those prescribed for workplace health and safety. The published data pertain to healthy adults. The elderly, the infirm, and infants will have varying reactions to levels considered acceptable for workplace employees.
Most fire department personnel are familiar with fire detection systems. However, other product-specific detection systems are in use and can activate, initiating an emergency service response (photos 3, 4). Gathering preincident intelligence on all detection systems is essential. The types of facilities that use atmospheric monitoring devices vary. Typical sites include water- and wastewater-treatment sites for chlorine. Cold storage warehouses often employ detection for anhydrous ammonia. Regardless of what material a fixed system is installed to detect, it is critical to know before an incident the activation limits and what the values mean. It is also imperative to understand the alarm monitoring, transmission, and emergency service notification processes.2
(3) An external facility detection warning device. 
(4) A fixed facility gas detection unit.
S = SCENE SIGNS
Sometimes it is obvious that a hazardous material release has occurred. Although it may be obvious, recognizing the scope of the situation and not responding with tunnel vision may reduce or prevent harm to responders. A large fish kill in a waterway is an obvious scene sign that a waterborne contaminant is or was present. A vapor cloud escaping from a tank or a pipe, in most cases, is not normal. A defined vegetation kill can be a result of an aboveground hazardous materials release or a belowground product conduit rupture. Another scene sign may involve multiple people or animals downed or showing symptomatic distress, which would indicate an airborne release of a material. Regardless, carefully evaluate scene signs so that your actions do not further endanger responders.
C = CONTAINERS
Containers vary in size, shape, and material. Hazardous materials are not stored exclusively in a particular type of container. Gathering preincident intelligence on fixed facility hazardous materials storage mediums is important for preincident training and response size-up. This article cannot review all of the container types in use. The intent is to stress the importance of identifying product containers and their contents (photos 5, 6).
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| (5) A large fixed facility container of hazardous materials. |
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| (6) Small-quantity containers of hazardous materials. |
From aboveground pressurized tanks to totes to fiber drums, the containers used to store materials are endless. Sizes range from hundreds of thousands of gallons to ounces. Regardless of the size, you must acknowledge that hazardous materials exist, identify the contents, and be able to research the materials’ characteristics and effects when improperly used or released.
Review storage practices and identify their limitations. Often, aboveground storage tanks are placed within a containment basin (photo 7). This can lead fire officials to a false sense of complacency if there is a breach in the container. In most cases, containment systems are designed to contain a 110 percent product release of the largest tank. Although this does present some “wiggle” room, a tank from a basin usually is designed with the same guideline. The basin is typically designed for the largest tank and not 110 percent of the capacity of all the tanks combined. This should be a significant consideration for incident commanders when mitigating tank-farm incidents.
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| (7) A containment basin with three 30,000-gallon tanks of styrene. |
U = USE OF THE SITE
The facility’s use can be a clear indicator that hazardous materials exist or are used. It is not always obvious, but understanding the facility’s use can be key. Hazardous materials are stored, used, and manufactured everywhere. And although the use component may appear to favor industrial sites, it includes garnering a true understanding of inherent hazardous materials use. From mercantile establishments to recreational sites to infrastructure (photo 10) to homes, the use of hazardous materials is ubiquitous.
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| (8) A mercantile establishment. |
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| (9) A pool house with chlorine at a community swimming pool. |
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| (10) A telephone switching office with battery power backup often contains sulfuric acid. |
M = MARKINGS
There are many marking systems, and it is crucial that you are familiar with them. Some are very specific; others present only generic information. In transportation, vehicles transporting certain types and quantities of hazardous materials must display a placard on all four sides of the vessel that identifies the material’s hazard class and, in some instances, a chemical-specific number that can be cross-referenced in the 2008 Emergency Response Guidebook (ERG).
Packaged containers may also have labels similar in stature to the placards. Regardless of whether a label or a placard is presented, each has four basic features. One is a pictograph that can be associated with the hazard classification. A corrosive, for example, yields two graphics, including deterioration of both a steel rod and the skin. The background color, in most cases, can be associated with a particular hazard class. A red background would be indicative of a material with flammable or combustible characteristics. A blue background is indicative of materials that are dangerous when wet; an all-yellow background represents an oxidizer (photo 11).
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| (11) A placard. |
The center of a placard may include the generic hazard class name or a specific four-digit United Nations number. This number correlates to materials listed in the ERG. The fourth element is a numerical hazard class indicator at the bottom diamond point. This is very important. A red placard with a “3” in the bottom point indicates a flammable/combustible liquid; a red placard with a “2” in the bottom point signifies a flammable gas; an all-white background signifies a toxic material; a “2” in the bottom point indicates a gas; and a “6” signifies a liquid or solid material. This can be an important factor for developing strategies and assessing the risk.
Another system typically used for structures and bulk tanks is National Fire Protection Association (NFPA) 704, Standard System for the Identification of the Hazards of Materials for Emergency Response, better known as the “fire diamond.” In some communities, the authority having jurisdiction has adopted this standard; in other areas, it is voluntary, and few sites employ the mark. If a building or bulk tank is equipped with a fire diamond, it is important to understand what the marking is telling and not telling you (photo 12).
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| (12) An NFPA 704 fire diamond. |
The diamond is separated into four areas. The blue section represents the health hazard characteristics; the red section, flammability; the yellow section, reactivity; and the white section, special hazards. The blue, red and yellow sections contain numbers ranging from 0 to 4—the lower the number, the lower the hazard.
In the white section, the standard prescribes only three markings: “OX” indicates the product is an oxidizer; “W” with a slash through it indicates it is water reactive; and “SA,” the most misunderstood marking, stands for “Simple Asphyxiant,” which is a property that displaces oxygen. Nitrogen and argon are typical materials that warrant an “SA.” Study NFPA 704 to make sure you understand the meaning of the hazard-numbering system and other marking conditions (photos 13, 14).
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| (13) NFPA 704 marking on a bulk tank of liquid nitrogen. |
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| (14) A close-up of the NFPA 704 “SA” special indicator. |
Other indicators, not included in NFPA 704, may be placed in the white section. They include “CORR” for corrosive; “ACID,” which is self-explanatory; and “ALK” for alkaline.
Another marking system often found on workplace containers is the Hazardous Materials Identification System (HMIS) (photo 15), developed by the National Paint Coatings Association. It provides a hazard marking system similar to the fire diamond. The HMIS is also divided into a blue, red, and a yellow section that mirror the hazard categories in NFPA 704. The associated hazard level also ranges from 0 to 4—again, the lower the number, the lower the hazard.
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| (15) The HMIS label. |
The HMIS label offers an additional feature not provided in NFPA 704. The blue health section has two fields: The right field includes the numerical hazard value; an asterisk in the left blue field indicates the material is a chronic health hazard. The HMIS labels produced after April 2002 were modified. The yellow reactivity section was changed to an orange background, which indicates a product’s physical hazard. Both versions of the HMIS have a white section that indicates the appropriate personal protective equipment that should be worn when handling the product.
Many other labels are used to reveal general and specific hazards (photos 16, 17). Fire department personnel engaged in preplanning and emergency response should heed the label warnings. In the preplanning mode, further investigation may be needed to read the fine print of these markings to more accurately understand the hazard present. Facilities may also employ their own hazard marking system, which fire department personnel should identify and make sure they understand during preplanning efforts.
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| (16, 17) A “Danger” sign and warning labels are commonly used in workplaces to communicate general hazards. |
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The DEADSCUM acronym, although a basic concept, is a useful tool for promoting situational awareness before and while approaching an incident. Situational awareness of our surroundings is our first line of defense. If we do not recognize and fully understand the hazards that await us, we are destined to harm ourselves.
Sometimes harmful circumstances and hazards are not well known or communicated to personnel. Careful analysis of basic incident clues, both pre- and post-dispatch, is essential for effectively mitigating an incident as well as promoting the safety and survivability of our personnel.
Endnotes
1. See my article “Tier II Chemical Inventory Form: A Preplanning Resource,” Fire Engineering, March 1998.
2. See my article “Preplanning for Emergencies at Water Treatment Facilities,” Fire Engineering, August 2003.
ERIC G. BACHMAN, CFPS, a 27-year veteran of the fire service, is former chief of the Eden Volunteer Fire/Rescue Department in Lancaster County, Pennsylvania. He is the hazardous materials administrator for the County of Lancaster Emergency Management Agency and serves on the Local Emergency Planning Committee of Lancaster County. He is registered with the National Board on Fire Service Professional Qualifications as a fire officer IV, fire instructor III, hazardous materials technician, and hazardous materials incident commander. He has an associate degree in fire science and earned professional certification in emergency management through the state of Pennsylvania. He is also a volunteer firefighter with the West Hempfield (PA) Fire & Rescue Co.
