How to Respond to Chemical Spills

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bullet General Spills regulations and guidance
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Hazardous Materials Guide for First Responders - 
General Approach to a Hazmat Incident

Hazmat incidents occur under a wide variety of conditions. For some of these situations there are special considerations and concerns. Listed below are some of these considerations and concerns for Hazmat incidents involving highway transport, rail transport, marine transport, fixed facilities, pipelines, radioactive materials, cryogenic tanks, chemical and biological terrorism and illegal or clandestine drug laboratories.

Highway Transport: Accidents on highways involving trucks carrying hazardous materials are perhaps the most common cause of Hazmat incidents. Many of these incidents occur in heavily populated areas and may involve large quantities of hazardous materials. Shipping papers are kept in the truck cab, which may be inaccessible if there is a leak or fire. Shipping papers will include a contact telephone number for emergency information. DOT placards provide information on the nature of the cargo. Unfortunately, some trucks containing hazardous materials may not have placards, either in violation of DOT regulations or because the quantities of material being transported do not require a placard. Placards don't always tell the whole story. Trucks can carry dangerous amounts of hazardous materials and still be under the legal amount required to have a placard. Many UN Numbers, which may appear on or below the placard, represent a variety of compounds which may pose varying risks. If the shipper and truck numbers are know, CHEMTREC7 (1-800-424-9300) can often identify the cargo. Any truck or van should be assumed to contain hazardous materials. Until the cargo is identified all action should be undertaken from a safe distance. Tank trucks, in particular, often contain materials which may explode or BLEVE. If it is possible, cool tank trucks exposed to heat with water from an unattended monitor. This should only be considered if an adequate water supply is available and enough trained personnel are quickly on the scene.

Rail Transport: Hazmat incidents involving trains are often complicated by the large amounts and numbers of materials found on a single train. These materials may chemically interact if they come in contact with one another. This creates a major risk of personal injury or property damage, further compounding the problem. Train incidents also may occur in relatively remote areas, which may limit the availability of personnel, equipment, and water. Shipping papers on trains are found with the engineer in the first engine. Initial assessment should be done from a safe distance through binoculars without approaching a train. There may be sufficient information on the outside of the rail cars to identify the materials they contain. The silhouette information may also be helpful in identifying different types of cars and their possible cargoes. Many materials shipped by rail will BLEVE if their tanks are heated by fire. These tanks may travel several thousand feet. It is generally best to maintain a safe distance until trained personnel and equipment arrive. Remember, if there is a fire stay away from the sides of cars and the train because of the risk of a BLEVE.

Marine Transport: Shipboard incidents in which land based responders are involved usually occur in heavily populated port areas. The quantities of hazardous materials involved can be very large, creating huge potential risks to adjacent populations and property. Cargos may also contain multiple chemicals with the possibility of chemical reaction. Most ships and barges will not be labeled or placarded. Shipping papers or manifests for cargo are usually located with the first officer on the bridge of a ship. On a barge, shipping papers are in a tube-like container or mailbox on the deck. The Coast Guard Captain of the Port is responsible for dealing with releases and fires. Frequently land based responders are called upon to assist in the incident response. Land based responders in port areas need to be familiar with the various jurisdictions and issues relating to both shipboard fires and waterway pollution. All ships and most towboats have crews who are trained to deal with releases and fires.They also will have varying amounts of on-board fire fighting equipment. Towboats may not have adequate equipment to fight on-board fires. Barges do not have adequate equipment to fight on-board fires or control releases. Fire companies responding to marine incidents should be equipped with International Shore Connection fittings to permit the pumping of water from shore into the firefighting system on board ship.

Fixed Facilities: Fixed facilities include both open facilities such as bulk liquid terminals and open processing areas, and closed facilities such as manufacturing or processing plants, laboratories, warehouses, and retail establishments. In general, the quantity of material in fixed facility incidents has the potential to be very large, particularly if there are large storage containers on site. There are also likely to be several hazardous materials at any given site. Identification of the materials at a site may be made from labeling, MSDS provided by facility personnel or from community inventories provided under SARA Title III. NFPA 704 placards may provide general information about the nature of the hazards in a particular facility or building (see Table 1 ). The NFPA 704 designations indicate the most severe risks associated with all of the materials in the building or facility. Be aware that buildings or containers may have inaccurate placards. Fixed facilities are often in industrial zones and may have other hazardous materials sites located in close proximity. There may also be many people working on or close to the site.

First Responder actions at a fixed facility Hazmat incident should be defensive in nature. After rapidly assessing the situation, notify the appropriate authorities and support services. Deny entry to the building or facility and consider evacuation. If a multi-story structure is involved and the released material is a gas that is heavier than air, it may not be desirable to evacuate the upper floors of the building. A decision can be made to shut down the heating, ventilating, and air conditioning (HVAC) system in a building if the risk of evacuating and dispersing a gaseous material appears greater than the explosion or flammability risk of leaving it contained in a portion of the building. Refer to this guide or other sources of information for aid in making that decision. If the HVAC is left on, it may also be possible to increase dispersion by leaving other building doors and windows open. For liquid releases from storage tanks it may be possible to prevent spread by diking or damming. This must be done well ahead of the liquid to prevent exposure of personnel and should only be attempted if it can be done safely.

If there is a fire, it may be preferable not to extinguish it until the nature of the material(s) is known and adequate resources are assembled. For some materials, allowing them to burn poses much less risk to the responder and surrounding areas than trying to extinguish them. It may be possible to protect surrounding structures or storage tanks by the use of a cooling fog stream, preferably from an unattended monitor. For some materials, fog streams can be used to suppress or disperse vapor releases. Information on all of these approaches will be found in the material specific sections of this book. Liquid chemical tanks exposed to flame impingement may explode or BLEVE, so maintain a safe distance if a fire is present. Many fixed facilities may have firefighting capabilities, including sprinkler systems and/or special suppressing or extinguishing agents. These may help to suppress fires. They may also suggest what firefighting agent is appropriate for the materials involved.

Pipelines: Pipelines carry many hazardous materials. If a pipeline breaks, very large quantities of materials can be released over a short period of time. Depending upon the material, this means that the cloud, fire, or release could be very large and will continue to grow until the flow stops. The key is to minimize the release by cutting off the flow at the pumping station or other shutoff. This will generally be done by pipeline personnel. Do not fight the fire or approach the scene until the flow has been stopped.

Radioactive Materials: There are many radioactive materials in commerce, usually in small quantities. Larger quantities may be encountered at fixed facilities. All containers, including packages, vehicles, and rail cars, containing radioactive material are required to carry a warning label or placard. Buildings or containers at fixed facilities containing radioactive material should also carry appropriate warning labels. If such a label is present at the scene of an accident, First Responders should generally back off until trained personnel and appropriate equipment are available to assess the situation.

There are several types of radiation hazards. Different radioactive materials produce different types of radioactivity. The most common radioactive materials in commerce produce alpha and beta particles. Other materials may produce x-rays, gamma rays or neutron particles. While all of these can potentially damage human tissue, alpha and beta particles do not penetrate the skin, so will not cause damage unless the actual material emitting these particles gets into the body by swallowing it, breathing it in, or getting it into an open wound. Avoiding physical contact with the material prevents these potential injuries. X-rays, gamma rays, and neutron particles do penetrate clothing and skin and can cause damage if the amount of radiation is sufficient. Exposure to these forms of radiation is only prevented by using a heavy metal shield. As with alpha and beta particle producers, contact with the material must be avoided. Injury caused by radiation may not develop for many days or even years after exposure.

Radioactivity is not destroyed by fire. In fact fire, explosion, and water dispersion as part of a fire may make a radioactive material incident worse by spreading radiation-emitting material over a large area. Remember if you see a radioactive warning label or placard: Back off until the experts arrive.

Cryogenic Gases: Cryogenic gases are gases shipped and stored refrigerated and under pressure. Tank shape and a visible vapor cloud upon release should alert the First Responder to the presence of a cryogenic gas. When cooled to very low temperatures (less than -150 F) and/or placed under pressure, these gases become liquids that take up less space for storage and shipment. These gases, some of which are extremely flammable (hydrogen and LNG) or toxic (chlorine), pose a major risk to the first responder. All of these gases are released from storage vessels at temperatures so low that they will instantly freeze unprotected tissues like skin and eyes. The release of even small amounts of gas can produce large amounts of vapor. Leaking cryogenic containers should not be approached. Trained personnel and appropriate equipment are required to stop the leak. Materials on fire should be allowed to burn until the release can be stopped. It is important not to put water, fog, or foam on cryogenic tanks or pools of cryogenic liquids, whether or not they are burning. The water will act as a heater, increasing evaporation or burning. Water, foam, and fog cannot extinguish a cryogenic fire. The cold vapors rising from a pool of cryogenic liquid almost always hug the ground and drift downwind without rapid dispersion.

Chemical and Biological Terrorism: Chemicals have been used in organized warfare since World War I. While biological agents such as highly infectious and toxic bacteria ("germ agents"), have been researched as potential war agents since the 1930's, they have never been used on a large scale. In recent years, fears have mounted that both chemical and biological agents could be used in terrorist actions against either civilian or military targets. In fact, chemical agents have now been used in such a fashion.

For this reason it is important that first responders become familiar with possible chemical agents involved in these incidents and how to appropriately respond. While biological agents, like germ agents, could be used in terrorist attacks, they would most likely unfold as an outbreak of a disease. It is unlikely that first responders will find themselves involved in these kinds of incidents because identification and response would then be provided primarily by public health authorities. Nuclear terrorism is also a possibility, however, response to nuclear accidents or events is beyond the scope of this book and the scope of training of most First Responders.

While we tend to think of chemicals used in terrorist attacks as highly specialized substances designed for war, in fact, many common industrial chemicals have similar properties and toxic potential. Chlorine gas, for example, has been used as a war gas. Many experts in terrorism think it is more likely that terrorists would use these easily available chemicals instead of the more exotic agents designed for war. Terrorist incidents might well involve the sabotage of industrial complexes near densely populated areas. Therefore, the technical and response problems posed by such an incident would be almost identical to other scenarios discussed in this book. It is important to remember that if terrorism or sabotage is suspected by the first responder appropriate law enforcement personnel should be notified and, to the extent possible, attempts should be made not to disturb or destroy potential evidence. Concern for evidence should not, however, prevent the first responder from carrying out actions appropriate for the chemicals involved. It is also important to remember that terrorists may booby-trap a scene in order to hinder response and produce additional casualties. First responders must remain alert for such possibilities. Secondary explosives for instance can be set to be detonated by radio signals transmitted from approaching response vehicles.

Table 2 lists the kinds of chemical agents which have been used or proposed for use in terrorist attacks. The physical properties and symptoms they can produce in exposed individuals are also listed. Important information on all of these chemical agents can be found in this book, either in the Specific Materials Guides or in the Materials Summary Response Table. First responders should be familiar with the common physical symptoms caused by each kind of agent. These symptoms are likely to be the first clue that one of these agents is involved in an incident.

Illegal or Clandestine Drug Laboratories: Illegal or clandestine drug laboratories pose a new and often significant risk for first responders. Such operations may contain a wide variety of chemicals, particularly flammable solvents, which are used in the production of illegal drugs. Unlike most legitimate manufacturing facilities, it will usually be impossible to obtain a listing of the chemicals present. Most of the chemicals commonly used in these laboratories will be found in this book because they are also found in legitimate manufacturing facilities. Some of the drugs usually produced in these laboratories and some of the chemical intermediates with drug-like actions are not included in this book. There have been reports of serious injuries to first responders from exposure to these drugs and chemical intermediates. For this reason, if the presence of an illegal or clandestine drug laboratory is suspected, extreme caution should be exercised by the first responder and exposure to chemicals at the scene should be avoided. Law enforcement personnel should be notified about the laboratory and, to the extent possible, attempts should be made not to disturb or destroy potential evidence.

The chemical specific sections of this book are designed to remind the responder of many of the basics discussed above as well as provide information on what options need to be considered for each specific chemical.


There are a number of sources of information available to the First Responder. Listed on the Contacts Page are several national sources with which the First Responder should be familiar. Local and state sources of information such as health departments, Hazmat teams, industrial aid groups, emergency service agencies, and others should also be considered as valuable resources.

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This page was updated on April 27, 2006