A Guide to Hazmat Response

     Emergency responders routinely encounter hazardous-materials emergencies during the course of their regular work routine. Every emergency vehicle in the United States should be equipped with a reference that allows first responders to make appropriate, critical decisions regarding actions to protect themselves and effectively manage the incident for the first 15-30 minutes of a hazardous-materials or weapons of mass destruction emergency. The 2004 Emergency Response Guidebook (ERG) published by the U.S. Department of Transportation provides assistance in determining the appropriate safety equipment, emergency response actions and objectives during those first few critical minutes of a hazardous materials or WMD emergency.

     The guidebook utilizes 61 two-page, general-response guides, which provide basic information to the emergency responder. Each of these guides, located in the orange-bordered pages in the middle of the guidebook, provides a general description of the product type along the top edge of the page. The left-hand side of the page provides information regarding potential hazards associated with the products and public safety actions to be taken.

     Under the section listed "Potential Hazards," either "fire or explosion" or "health" will be listed first. The hazard listed first is considered the greatest hazard to responders for that group of materials. With the exception of all but one of the radioactive material guides, #161-166, structural firefighting clothing provides only limited or no protection for emergency responders. The right-hand page lists emergency response information, including how to respond to fires, what extinguishing materials to use, leak response procedures, and first aid procedures in the event of an injury or exposure.

Identifying Hazardous Materials
     In order to use the guidebook, the responder must first identify the material. There are several ways to accomplish this, each with varying degrees of accuracy. The method that is the least accurate is simply looking at the shape of the shipping container. Pages 18-19 of the ERG provide silhouette line drawings of common rail cars and road trailers used in shipping. Next to each line drawing is a circled three-digit number that identifies the appropriate ERG number. Unfortunately, many different types of materials can be transported in each of the containers, leaving the information provided prone to error. As a result, the shipping container identification charts should only be used as a last resort, and responders should continue to seek additional information regarding the contents of the containers.

     Many hazardous-materials shipments can be identified by diamond- shaped, colored placards, which are affixed to four sides of the shipping container. In the absence of the four-digit United Nations (UN) identification number, these placards provide general clues, using placard color, symbol, class and division number, and a hazard name or four-digit identification number to indicate the material properties and physical state of the material. A table of placards is on pages 16 and 17 of the ERG. Again, a three-digit number next to each set of placards indicates the appropriate guide number to be followed.

     If required, the four-digit UN identification number will be found either within the hazard placard or stenciled on an orange panel on the container. As with the placards, the UN number is located on four sides of the container. The UN identification number is unique to a material or a group of similar materials. Using the UN number allows responders to identify more specific response guides than either the container shape or a placard without the ID number.

     Intermodal containers may display an additional set of markings that include identification codes, which are two- or three-digit numbers, and the four-digit UN identification number located within an orange-colored panel. Hazard codes provide the class of material and a subjective degree of hazard when the hazard class is repeated. For example, a material having a hazard code of 30 is a flammable liquid, while a material with a hazard code of 33, the 3 being doubled, is an extremely flammable liquid. Other clues are provided in the hazard numbering system. If the number 9 appears as either the second or third digit, the material may carry a risk of spontaneous violent reactions; an X in front of the hazard code means the material will react dangerously with water. Hazard codes are listed on pages 20-23 of the ERG.

Chemical Reactions
     The preferred and most accurate means of determining the contents of a material in transit is to obtain a copy of the shipping papers. If completed correctly, the shipping papers will provide the name of the materials being shipped, shipper and receiver information, hazardous-material designation and contact information for securing emergency assistance. All of these can help the first responder determine what material is present and provide resources for bringing the incident to a safe conclusion.

     Once a UN identification number or name of the material is determined, the responder may turn to either the yellow-bordered pages that begin on page 25 and list hazardous materials by UN identification number, or the blue-bordered pages that begin on page 97 and list hazardous materials by name in alphabetical order. In both sections, you will find the name of the material, UN identification number and, right in between and in bold type, the appropriate emergency response guide number.

     Some of the materials, like styrene, UN #2055, list a P with the guide number, which indicates that the material is capable of polymerizing, and that any container it is in may fail violently if polymerization occurs. When polymerization occurs, the container's contents join together chemically and expand in size, often many times the original size of the container. If the container is unable to contain the expanding materials, it may fail violently, sending pieces of the container over a wide area at explosive speeds. A common example of a polymerization reaction is when spray foam is used to seal holes or cracks in walls. The foam is released from the container and expands to fill the void space.

     Many materials that can be used as terrorist agents are also listed in the yellow- and blue-bordered pages. For example, ammonium nitrate-fuel oil mixture, the material used in the bombing of the Alfred P. Murrah Federal Building in Oklahoma City, has no UN identification number but has an emergency response guide number of 112, indicating that it is an explosive material. Similarly, biological agents do not have designated identification numbers, but have an emergency response guide number of 158, which is used for initial response to infectious substances. Nerve agents are listed in the yellow-bordered pages under UN #2810 or #2811, and in the blue-bordered pages by name.

     When emergency responders are faced with a completely unknown chemical product, including any weapon of mass destruction, emergency guide 111 provides initial emergency actions to take while they continue to seek additional information. It is imperative that emergency responders identify the material involved by hazard class or, preferably, by name, in order to take the correct emergency actions and ensure responder safety and health.

     Some materials, such as pentaborane, UN identification #1380, have been highlighted in both the yellow- and orange-bordered pages. The highlighting indicates that if the material is involved in a leak or spill and not involved in a fire, there are special isolation and evacuation distances that must be followed. These are found in the green-bordered pages, which begin on page 300.

     Page 344 of the green-bordered pages lists materials like fluorosulfonic acid, ID #1777, which produces hydrogen fluoride gas when wet. All of the materials listed release highly toxic gases when wet. The guide lists procedures to follow should that happen.

     A listing of possible indicators of terrorist or criminal activity is found on page 354, and the inside of the back cover lists emergency contact information. This list includes the Chemical Transportation Emergency Center (CHEMTREC) and the National Response Center (NRC). The NRC should be contacted for any hazardous-materials release. Should the responder suspect or determine that the release is or may be of criminal intent, the NRC provides a back door into the federal response system for criminal and terrorist response.

Summary
     The Emergency Response Guidebook provides responders with important first response information. It is intended to assist in managing the first 15-30 minutes of an emergency response and should not be used as the definitive response resource. It does, however, provide information that can be used to identify protective clothing and response procedures that can save lives and initiate successful control of the incident. Using the known product information, responders can use the ERG to determine response procedures for emergencies involving chemicals in a fixed facility. Responders should review and practice using the guidebook on a regular basis.

Dave Donohue has 25 years of emergency response experience, including 23 years responding to hazardous materials. He holds an MA in Public Administration, with a major in crisis management and an MA in disaster science. He is currently a hazardous-materials training specialist in the Washington, DC, area.