A Guide to Chemical Profiling

BY GLEN D. RUDNER

While researching for a sound methodology to use for referencing known products on the scene of a hazardous materials or weapons of mass destruction (WMD) incident, the Virginia Department of Emergency Management’s (VDEM) Technological Hazards Division found a program that was reputable and backed by science.

The program, Chemical Profiling of Known Chemicals, originally came from the U.S. Coast Guard’s Environmental Response Division in Yorktown, Virginia. After evaluating the flow of the process, it was determined to make several adjustments that made it a response tool that could be used on hazardous materials/WMD incidents. It has been used now for almost 10 years by operations-level responders and hazardous materials technicians in Virginia with great success. In addition to being an excellent response tool, it is also an outstanding addition to any emergency response agency’s Risk Based Response (RBR) training program.

This article provides an overview of the chemical profiling system and a look at its application and use for emergency response operations at hazardous materials incidents.

WHAT IS CHEMICAL PROFILING?

Chemical profiling is a process that looks at and identifies the physical behaviors and hazards of the material and its energy. The first step is identification of the chemical. There are five evaluation points:

  1. The ability of the product to release energy.
  2. The physical state of the product (solid, liquid, gas, or liquid with a gas component).
  3. Flammability hazards.
  4. Health or toxicity hazards.
  5. Corrosivity hazards.

The process relies on five or six of the most commonly used hazardous materials reference choices, including the following:

  • US DOT Emergency Response Guidebook (Current Edition).
  • National Institute for Occupational Safety and Health (NIOSH) Pocket Guide to Chemical Hazards.
  • Chemical Hazards Response Information System (CHRIS) Manual.
  • NFPA Guide to Hazardous Materials.
  • Emergency Care for Hazardous Materials Exposure.
  • Hawley’s Condensed Chemical Dictionary.

Additional guides should include chemical protective clothing compatibility charts, chemical specific guidebooks, and manufacturers’ information for specific meters.

THE PROCESS

To start working toward a solution for the chemical hazards of the product, first identify the chemical. Identification clues that may be available to use include the following:

  • Identification (ID) numbers.If the chemical name is not provided, ID numbers can be a critical tool in identifying the involved materials.
    UN/NA number This four-digit number can be found on placards, shipping labels, subsidiary placards, shipping papers, and additional product labels.
    Chemical Abstract Service (CAS) number. Includes up to nine digits separated into three groups by hyphens. The first part of the number, starting from the left, has up to six digits; the second part has two digits. The final part consists of a single check digit.
    Standard Transportation Commodity Code (STCC). A seven-digit numeric code representing 38 commodity groupings. Assignment of a STCC code is associated with a commodity description developed to conform to exact descriptions in freight transportation classifications of rail and motor carriers.
  • Name and Hazard Class of the Materials. Specific knowledge of the materials involved can make it easier to identify their hazards. Remember that the ID numbers are used to find the name. Also, the hazard class can provide critical information in identifying the primary hazard of the material, even if its specific identity cannot be initially determined. Remember here that the material may have multiple hazards.
  • National Fire Protection (NFPA) Association 704, Standard System for the Identification of the Hazards of Materials for Emergency Response Marking System, 2007 Edition. This system can be found at fixed facilities; variations can be found on individual nonbulk containers as well. It provides responders with a quick overview of the hazards, including health (blue), fire (red), and reactivity (yellow) hazards. The fourth section gives a special warning (white) of additional chemical hazards. The hazards are denoted from 0-4, with “0” designating minimal hazard and “4” designating highest hazard.


Figure 1. Product ID

The next section of the chemical profile process is to determine whether the material is capable of releasing high amounts of energy. Remember that the quicker the juice comes out of the container, the less responders can do to influence the release (also, the greater the potential for harm). Responders must consider three basic types of high-energy release mechanisms:

1 Explosive. Is the material a U.S. DOT Hazard Class 1.0 material? Do you know its Division? Although all of these materials are capable of releasing high amounts of energy, depending on the hazard class involved, they will also have other hazards, including mass detonation, mass fire, or the release of projectiles.

2 Reactive. Does the material react with other chemicals? Are those chemicals present? Is the material air or water reactive (usually Hazard Class 4.2 or 4.3)? Does the product react with itself, or does it polymerize? Is the chemical itself unstable?

3 Radioactive. Does the material meet the classification of U.S. DOT Class 7? These are the only materials that qualify as radioactive.

If you look on the right side of the form in Figure 2, there is a Profile column. The reason for this column is so the responder can circle the hazard that has been defined by the reference point above. Now an initial report using the hazard information that has already been accumulated can be made. Using the information in the first and second sections, you can report on the primary hazards and start looking at the safety and personnel protection concerns.


Figure 2. High-Energy Evaluation

The next section helps in classifying the material’s physical state. Look at the ambient temperature, boiling point, and melting point. Based on these temperature reference points, the material can then be evaluated as a solid, liquid, liquid/gas, or gas.


Figure 3. Physical State

As a point of reference, use a boiling point of 3,000°F (148.9°C) as a safety break. Remember, the lower the boiling point, the higher the vapor pressure and the more likely the product will volatilize or become a vapor. Another important chemistry point is that there is a direct correlation between the boiling point and the vapor pressure of a product.


Figure 4. Gas Hazards

Once referenced, the boiling and melting points will assist in determining the physical state of the product, and the profile, based on the physical state, can be completed.

VAPOR HAZARDS

When evaluating the hazards of a gas, initially evaluate the following properties:

  1. Flash point.
  2. Ignition temperature.
  3. Explosive limits (LEL-UEL).
  4. Vapor density.

They will give you information with regard to the flammability of the material and the degree of the hazard. Now, look at the next section, which focuses on the health hazards:

  1. Carcinogen.
  2. Lethal concentration (50% Kill) or LC50.
  3. Permissible exposure limit (PEL).
  4. Short-term exposure limit (STEL).
  5. Immediately dangerous to life and health (IDLH).

LIQUID HAZARDS

When evaluating a liquid hazard, initially consider the following properties: solubility and specific gravity. This will give information as to the behavior of the liquid component of the material.


Figure 5. Liquid Hazards

Now, look at the following in the next section:

  1. Carcinogen.
  2. Lethal dose (50% Kill) or LD50.
  3. Permissible exposure limit (PEL).
  4. Short-term exposure limit (STEL).
  5. IDLH.

SOLID HAZARDS

When evaluating a solid hazard, look at the following properties first: sublimation (the ability of a material to change from a solid state to a vapor state) and combustibility (the ability of a material to burn).


Figure 6. Solid Hazards

They will provide information as to the behavior of the solid component of the material. Note that if the solid meets the criteria of sublimation, then the vapor product must also be evaluated.

Now, look at the following in the next section:

  1. Carcinogen.
  2. Lethal dose (50% Kill) or LD50.
  3. Permissible exposure limit (PEL).
  4. Short-term exposure limit (STEL).
  5. IDLH.

This information, gathered for vapor hazards, liquid hazards, and solid hazards, can assist emergency responders in evaluating potential health effects and in making initial decisions pertaining to the selection of PPE and tactics for the protection of civilians.

The last piece of information is pH, the measurement of the corrosivity of the vapor/gas. Responders are typically confronted with either strong acids (pH <3.0) and strong bases or caustics (pH > 12.0).

•••

The Chemical Profiling System is an effective tool emergency responders can use as part of initially sizing up and determining the hazards and risks presented during a hazmat/WMD incident. The information garnered through this process can assist responders in quickly profiling the behavior of the product involved and in developing safe tactical decisions as part of a solid incident action plan.


Figure 7. Incident Analysis Worksheet

Research, or knowing the technical reference guidebooks and other resources available in your response library, is a skill that is perishable and must be maintained. Take the opportunity to use the Chemical Profiling Process when doing walk-through inspections or conducting preincident plans of target facilities, as well as when walking through various hazmat/WMD response scenarios.

GLEN D. RUDNER has been a hazardous materials officer for the Virginia Department of Emergency Management for the past 10 years. During the past 30 years, he has been involved in the development, management, and delivery of local, state, federal, and international training programs. He has authored many public safety publication articles and is a voting member of the NFPA and the IAFC Hazardous Materials committees.

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