Fire and Spill Control

Fire and Spill Control, page 355FIRE AND SPILL CONTROL FIRE CONTROL Water is the most common and generally most available fire extinguishing agent. Use caution in selecting a fire extinguishing method, as there are many factors to consider. Water may be ineffective in fighting fires that involve some materials. Fires Involving a Spill of Flammable Liquids These fires are usually controlled by applying a firefighting foam to the surface of the burning material. Fighting flammable liquid fires requires: • foam concentrate that is chemically compatible with the burning material • correct mixing of the foam concentrate with water and air • careful application and maintenance of the foam blanket There are two general types of firefighting foam: regular and alcohol-resistant. Examples of regular foam are protein-base, fluoroprotein, and aqueous film-forming foam (AFFF). You can control some flammable liquid fires, including many petroleum products, by applying regular foam. Other flammable liquids, including polar solvents (flammable liquids that are water soluble), such as alcohols and ketones, have different chemical properties. You cannot easily control a fire that involves these materials with regular foam, and should use alcohol- resistant foam instead. Polar solvent fires may be difficult to control and require a higher foam application rate than other flammable liquid fires (see NFPA Standards 11 for further information). Refer to the appropriate guide to determine which type of foam to use. For flammable liquids which have subsidiary corrosive or toxic hazards, it is difficult to make specific recommendations. However, alcohol-resistant foam may be effective for many of these materials. Contact the emergency response telephone number on the shipping paper, or the appropriate emergency response agency, as soon as possible for guidance on the proper fire extinguishing agent to use. How you decide to control the fire depends on factors such as: • incident location • exposure hazards • size of the fire • environmental concerns • availability of extinguishing agents and equipment at the scene WATER-REACTIVE MATERIALS Water is sometimes used to flush spills and reduce or direct vapors in spill situations. Some of the materials covered by this guidebook can react violently or even explosively with water. In these cases, consider letting the fire burn or leaving the spill alone (except to prevent its spreading by diking) until you can get more technical advice. Page 353#

Fire and Spill Control, page 356The applicable guides clearly warn you of these potentially dangerous reactions. Technical advice is required for these materials since: • • • • Water getting inside a ruptured or leaking container may cause an explosion. You may need to cool adjoining containers with water to prevent them from rupturing (exploding), or to prevent the fire spreading further. Water may be effective in mitigating an incident involving a water-reactive material, but only if you can apply it at a sufficient flooding rate for a long period. Products from the reaction with water may be more toxic, corrosive or undesirable than the product that caused the fire. When you respond to an incident involving water-reactive materials, take into account: • existing conditions, such as wind, precipitation, location and accessibility to the incident • availability of agents to control the fire or spill Because there are variables to consider, base your decision to use water on fires or spills involving water-reactive materials on information from a reliable source. For example, consult the material’s manufacturer through the emergency response telephone number or the appropriate emergency response agency listed on the inside back cover. VAPOR CONTROL Limiting the amount of vapor released from a pool of flammable or corrosive liquids is an operational concern. It requires proper protective clothing, specialized equipment, appropriate chemical agents and skilled personnel. Before you engage in vapor control, seek advice on tactics to be used from qualified personnel. There are several ways to minimize the amount of vapors escaping from pools of spilled liquids, such as special foams, adsorbing agents, absorbents, and neutralizing agents. To be effective, you must select a method for the specific material involved, and use it in a way that mitigates, not worsens, the incident. Where specific materials are known, such as at a manufacturing or storage facilities, the hazardous materials/dangerous goods response team should prearrange with the facility operators to select and stockpile these control agents before a spill. In the field, first responders may not have the most effective vapor control agent for the material available. They will be more likely to have only water, and only one type of firefighting foam on their vehicles. If the available foam is not appropriate, they will probably use water spray. Because water is being used to form a vapor seal, care must be taken not to churn or further spread the spill during application. Vapors that do not react with water may be directed away from the site using the air currents surrounding the water spray. Before using water spray or other methods to safely control vapor emission or suppress ignition, get technical advice based on a specific chemical name. Page 354#

Fire and Spill Control, page 357LIQUID SPILL CONTROL Spill control is an important part of any hazardous materials/dangerous goods incident. Spills can have serious health, safety, and environmental consequences. There are many ways to deal with a liquid spill, like: • diking • damming, and • absorbing A liquid spill can be controlled by setting up a barrier around the spill area. Depending on the product involved, the spill can be contained with either inert or non-combustible absorbent materials. Inert absorbent materials are granular. The most common types are: • sand • diatomaceous earth (a fine powder made from sedimentary rock) • vermiculite, or • clay Non-combustible absorbents are usually not very flammable and can absorb a lot of liquid. These materials are usually made from synthetic materials, like: • polypropylene • polyethylene, or • other synthetic fibers Other absorbent materials that are easy to find include sawdust or clay litter. Please note the following: • • Sawdust should not be used to absorb flammable liquids or oxidizers since it can catch fire Clay litter should not be used to absorb acids since it may contain baking soda, which will react with acids Before using an absorbent material, get technical advice to confirm its compatibility or test a small amount on the spill. Page 355#