BY DAVID F. PETERSON
Without a doubt, gasoline is the hazardous material most commonly released in the United States every year. It is the primary fuel for vehicles, and its consumption is high. Spills occur at vehicular collisions, pipeline releases, bulk transport container leaks, and fixed container storage sites. As most of us know, the innate physical hazard of gasoline is flammability and gasoline, as a liquid at ambient temperatures, will evolve flammable vapors as low as 1457F. Therefore, gasoline can burn or combust virtually anywhere in the continental United States at all times of the year.
When gasoline does burn, its heat of combustion is enormous! One pound of gasoline will provide approximately 21,000 British thermal units (Btus) when it combusts. Since a gallon of gasoline weighs 6.67 pounds, each gallon provides approximately 140,112 Btus when it completely burns. This is a great deal of energy, and anyone who has experienced gasoline fires can attest to the fact that the thermal energy is awesome.
Gasoline fires will burn at a rate of approximately 12 inches per hour. This means that a spill one-eighth of an inch deep (.125 inch) will burn away in about 37.3 seconds, whereas a spill one-sixteenth of an inch deep (.0625 inch) will burn away in about 18.67 seconds. Imagine a gasoline spill of 10 gallons that has spread across a parking lot and achieved a depth of .125 inch when ignition occurs. In the 37.3 seconds it would take for the gasoline to burn away, more than 1.4 million Btus would have been produced. It is hard to turn your back on such a powerful beast, but many burn victims fall prey to the dangers of gasoline each year.
Additionally, the gasoline additive methyl, tertiary, and butyl ether (MTBE) and other gasoline additives have proven to be health hazards, especially when releases contaminate groundwater. MTBE and ethanol are used to enhance the performance of and oxygenate gasoline. As polar solvents, they profoundly can alter the characteristics of gasoline. Depending on the polar solvent concentration, it can cause the gasoline to burn hotter; an alcohol-resistant type of foam will be needed for extinguishment. All of these hazards, coupled with general complacency, make gasoline releases very dangerous for responders. Therefore, it behooves responders to develop and use safe procedures when dealing with gasoline releases, both large and small.
RESPONDING TO A GASOLINE RELEASE
When responding to a gasoline release, start with your communications center. On your past initial dispatches, have you been directed to respond to a “gas leak”? The term “gas” is a vague term that can mean gasoline but can also mean a natural gas/methane or even a propane release. Because this term can be confusing, its use should be discontinued. If a caller reports that gasoline has been released, responders must be told that. If you are paged to respond to a “gas leak,” you must request additional information while en route. Positively identifying the product released is a must.
The communications centers must also discontinue paging response crews to “gas flushes.” This is a poor practice because flushing hazardous materials, including gasoline, into storm sewers and the environment is illegal in most states. Also, paging responders in this fashion plants the tactic of flushing gasoline with water in responders’ mind and can lend a degree of implied legitimacy to the tactic. In fact, the only time flushing gasoline is legitimate is when human life is in imminent danger, such as a vehicular collision with trapped occupants.
How many of you have stood in gasoline while extricating or treating victims? There is a better way. The first rule of response is to make the scene safe for responders. At vehicular collisions, conduct outer and inner surveys before committing personnel to rescue efforts. These surveys need to include looking for hazards to personnel such as downed electrical wires, trip hazards, and the presence of hazardous materials, which includes gasoline. Before working at these scenes, eliminate or at least control the flammability hazard.
Perhaps the best method of control is to cover the gasoline with Class B foam. At large spills, use hoselines, portable foam eductors, and foam concentrate. Small spills can be handled with commercially available Class B foam extinguishers. Apply this foam solution under pressure to the spill to help prevent the generation of flammable vapors. Be sure to flush the solution out of the extinguisher after the incident because of the foam’s corrosive nature.
Keep these additional thoughts in mind while working at gasoline releases. Strive to stay out of product if at all possible because of the effects of gasoline on protective clothing, especially firefighting boots. Gasoline is also a powerful solvent that will dissolve similar materials such as rubber and the adhesives used in boot construction. Decontaminate all protective clothing with soap and water immediately after the incident, and monitor the items for signs of degradation. Also, consider eliminating all ignition sources (including road flares), and use precautionary staffed hoselines to help ensure responder safety.
Response to gasoline spills varies greatly from fire department to fire department. Some departments still illegally flush gasoline spills with water; others apply emulsifiers and then flush the spill. The problem with emulsifiers is that they provide only a temporary solution. The gasoline gets suspended in the soapy emulsifier, especially after agitation or mixing, such as with a broom. After this suspension is flushed away, the process of separation starts to occur with the ultimate result being the gasoline’s floating on the surface of the body of water to which it has been flushed. For this reason, emulsifiers have not been approved for use in many states.
For gasoline spills, many departments also apply oil “speedy” dry or some other type of absorbent. Ideally, the gasoline coats the absorbent particles for ease in “picking up” the liquid. Some departments containerize the saturated absorbent for later disposal; others merely leave the absorbent where the spill occurred. Examination of this procedure reveals faulty thinking. Absorbing the gasoline with the absorbent increases the surface area in which vapors can evolve. Since it is the vapors that combust, there is now a pile of solid material saturated with gasoline at the scene. To leave the absorbent at the scene, then, becomes irresponsible and may even increase the department’s liability.
Perhaps a better method would be to sweep up the saturated absorbent with nonsparking equipment and dispose of it in sealable, hazardous waste plastic bags. This procedure will remove the flammability hazard from the scene and decrease the chance of a fire. A jurisdiction’s hazardous waste contractor can then collect the waste. Under no circumstances should fire department vehicles transport hazardous waste or take it back to the fire station.
One last option to keep in mind with gasoline spills concerns evaporation. Gasoline will evaporate fairly rapidly, especially on a warm or hot day. Secure the area, eliminate ignition sources, stay upwind, and simply let the spill evaporate. Since this works very well with small and shallow spills, sometimes the best action is no action.
There are many options for gasoline leaks from vehicle tanks. The source of the leak can be located and the tank plugged with small wooden or rubber plugs or pliable putties. These quick fixes allow the owner some time to get the vehicle to a repair center. Quite often, the source of the leak is a corroded seam on the tank. Since Americans are keeping their vehicles longer, responders may encounter automobile gasoline tank leaks more frequently.
One problem with gasoline tank leaks is that responders may get splashed or contaminated by the product. Since the product combusts, is skin-absorbable, and contaminates firefighter gear, it would be prudent to use gasoline-resistant clothing over the firefighter gear, which provides flammability protection. To better address these situations, some fire departments have assembled gasoline response kits for each of their fire engines. All components are considered disposable; the cost of each kit is approximately $260. The kit includes the following:
- two pairs of safety goggles;
- two pairs of nitrile gloves;
- two pairs of KevlarT gloves;
- two pairs of polyethylene or silver-shield sleeves;
- a 5- 2 7-foot polyethylene tarp;
- leak-sealing equipment, such as: putty (two rolls)gap seal (one tube);
- assorted wooden dowels, plugs, and golf tees; and
- a wooden hammer.
All of this equipment fits into a 9- 2 8- 2 16-inch plastic tackle box (for easy carrying). These kits also work well for diesel fuel leaking from the saddle tanks of large trucks. Even though these tanks present a large amount of product, consider using the kit to slow down or stop a leak until the haz- mat response team or private contractor arrives.
At all leaks, consider collecting or confining the product by using buckets or tarps configured as pools.
A mitigation technique some fire departments have used for a gasoline tank leak is called the “Paul Bunyan Technique.” In this crude and potentially dangerous procedure, a large hole is made in the tank with an ax, to completely drain the product. The advantage is that the leak will unquestionably come to an end and the fire company will not have to return. However, the disadvantages are the potential for fire and negative public relations for the fire department. Hopefully, responders have seen the light, and this procedure will become extinct. Remember, complacency kills!
A safer alternative, and one in the best interest of public safety, is to off-pump the contents of a leaking automobile gasoline tank into approved flammable liquid safety containers. This procedure, usually conducted by haz-mat response team personnel, removes the hazard safely, gives better protection to the environment, and prevents the return of fire companies. The gasoline is transported back to the fire station and can be reclaimed by the owner within 48 hours. The owner of the vehicle may not be too happy, but it forces him to repair the problem.
Many responders arrive at vehicular collisions in station gear or work uniforms. This practice needs to be reconsidered. In one horrific incident that occurred in the 1980s, a fire crew responded to a report of a one-vehicle incident in which a car was on its roof. On arrival, fuel leaking from the tank ignited, and four young men were trapped in the vehicle. The responders arrived in their station uniforms. As they hurriedly donned their bunker gear, the four men in the car perished. The Boy Scout motto “Be prepared” never rang truer. Wear your firefighter gear to all incidents involving gasoline and other flammable liquids because your life, or someone else’s, may depend on it.
DAVID F. PETERSON, a 20-year veteran of the fire service, is a lieutenant with the Madison (WI) Fire Department. Previously, he was a training coordinator for the Regional Level A Haz Mat Response Team. He is the owner of Americhem Safety & Environmental, LLC, a haz-mat training and consulting firm in Janesville, Wisconsin. He is also a master trainer, an adjunct instructor for the National Fire Academy and the Emergency Management Institute, and a frequent lecturer and author. He is the founder and past president of the Wisconsin Association of Hazardous Materials Responders, Inc.