Incidents fire, exposure, chemicals

For the purpose of this article, fire tests are associated with the second strategy and defined as experimental methods to characterize the behavior of polymers under more severe thermal exposure conditions that are representative of the growth phase of a compartment fire. These conditions are simulated with a gas-fired or electrical heater or a large gas burner turbulent diffusion flame (flame length of the order of a meter or several feet). The incident heat flux to the specimen is primarily radiative when heaters are used, and mainly convective for flame exposure. Total incident heat flux varies from approximately 1 kW/m to more than 100 kW/m. Note that the maximum radiant heat flux from the sim on earth is approximately 1 kW/m. Polymers that are not treated with fire retardant chemicals typically ignite when exposed to heat fluxes of 10-20 kW/m in the presence of a small pilot flame or hot spark. 

The exposure potential from adjacent facilities due to catastrophic incidents such as a fire, explosion, or a chemical release should be identified when conducting a site assessment. Reassessments of nearby facilities may also be warranted as changes to the surrounding exposures occur over time. High hazard or poorly protected operations may present a risk to a nearby chemical warehouse. The most effective approach for minimizing the exposure is usually sufficient spatial separation or fire walls. Locating a chemical warehouse adjacent to airports, highways and railroad lines may also result in an exposure, albeit remote. 

During a normal chemical reaction to create a particular polymer from a monomer, a catalyst is used to control the reaction. A catalyst is any substance that in a small amount noticeably affects the rate of a chemical reaction, without itself being consumed or undergoing a chemical change. For example, phosphoric acid is used as a catalyst in some polymerization reactions. Once an uncontrolled polymerization starts at an incident scene, it will not be stopped until it has completed its reaction, no matter what responders may try to do. If the polymerization occurs inside a tank, the tank may rupture violently. If a container of a monomer is exposed to fire, it is important to keep the container cool. Heat from an exposure fire may start the polymerization reaction. In Figure 5.18, the monomer vinyl chloride is shown along with the process of polymerization of the vinyl chloride molecules. 

Caution should be observed if fire is involved in an incident, since many small containers can become projectiles as pressure builds up inside from the heat and the containers explode. Aerosol cans may be particularly dangerous because they are already pressurized, and exposure to heat can cause them to explode and rocket from the pressure. Those materials used in industry and institutions are usually service products used in cleaning and maintenance rather than in industrial chemical processes. 

Fires in CDLs can spread rapidly. If significant quantities of chemicals are present, efforts should be limited to protecting responders from exposure. Consider evacuation of personnel from downwind of tbe area. It is best to be upwind and on higher ground. Fire service personnel should consider a defensive mode in a known CDL. This means that they do not enter the structure but fight the fire from outside (surround and drown). Runoff water can be contaminated and needs to be controlled. Notify the EMA and environmental protection agencies early into the incident. Law enforcement should make certain that EMS and firefighters know that a suspected or known CDL is involved. If EMS or fire personnel (or private citizens) accidentally discover a CDL, they should retreat and call law enforcement. 

Finally, despite efforts to prevent incidents (accidents) and exposure in the laboratory, it is prudent to prepare for them. Thus, we present the fourth principle prepare for emergencies. What kinds of emergencies can happen in a laboratory Fires, explosions, exposures to chemicals, personal injuries—all the sorts of hazards that have already been considered Preparing for emergencies involves knowing what safety equipment is readily available and how to operate it (see Figure 1.1.1.3). You also need to... 

INCIDENT 8.3.2.1 CHEMICAL EXPOSURE AND FIRE FROM AN OLD STORED CHEMICAL ... 

The Dow Fire and Explosion Index (FEI) (Dow, 1994 Van den Braken, 2002) and the Dow Chemical Exposure Index (CEI) have been developed and practiced hy Dow Chemicals for several decades. These tools measure process inherent safety characteristics, help to quantify the expected damage of potential fire and explosion incidents, and identify equipment that would likely contribute to the creation of the incident. The Mond Index was developed by ICI (UK) from the Dow Fire and Explosion Index. The Mond Index includes toxicity and covers a wider range of processes and storage installations than the FEI. The various aspects considered in the FEI are material factor (flammability and reactivity), general process hazards such as exothermic/endothermic reactions, and special process hazards such as toxic nature of the chemicals and dust explosion. For example. Table 8.6 shows the results of the FEI for various inventory levels of storage of ethyl acrylate. 

It is estimated that some 32 million workers are potentially exposed to approximately 650,000 existing chemicals in the workplace. Chemicals can pose a serious hazard for every employee in a warehouse. Chemical exposure may cause or contribute to many serious health effects such as heart ailments, kidney and lung damage, sterility, cancer, burns, and skin rashes. Some chemicals may also be safety hazards and have the potential to cause fires, explosions, and other serious incidents or injuries. 

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