FIRE LOSS MANAGEMENT
Part 5: THE UNFRIENDLY CAUSES OF FIRE
DISASTER MANAGMENT
UNFRIENDLY CAUSES of fire are usually forces or actions that serve no practical purposes in and of themselves. The principal unfriendly causes of fire are lightning, static electricity, arson, metallic sparks, and spontaneous ignition.
It would at first appear that you can control these causes by simply eliminating them. Indeed, elimination would be ideal. However, the effort devoted to elimination either doesn’t guarantee success or is economically unjustified in terms of results. Directly attacking the cause often turns out to be a wasted effort; it is often better to recognize that the cause exists and to manipulate extension and management to prevent fire disasters. Following is a brief description of some of the unfriendly causes.
LIGHTNING
Lightning protection must be correctly installed, properly maintained, and complete. Proper installation is so important that Underwriters Laboratories requires a field inspection before labeling. An inadequate lightning protection system can make the structure a more likely target than no system at all. A structure so protected is truly a client of “The Falsenza Security Company.”
If an airplane disintegrated over the city, showering flaming wreckage, we would certainly send out units to look for fires caused by such wreckage. No flaming wreckage has more fire-causing potential than a storm with incendiary bolts of lightning. Yet we usually wait for a citizen to report a well-advanced fire in a remote location, minutes or even hours after the lightning struck, before sending out units.
Certain buildings are more likely than others to be struck by lightning. The fire department should make sure that such buildings are inspected soon after a lightning storm occurs. Keep an index file of telephone numbers of custodians to call to make inspections or send units to make the inspections. Inaction or hesitation can result in the heavy loss of important buildings in your jurisdiction that may have been hit by lightning. (For a complete discussion of lightning, see Section 12, Chapter 12 of the NFPA’s Fire Protection Handbook, 16th Edition.)
STATIC ELECTRICITY
A static electrical charge is produced from the buildup of positive and negative charges formed through the physical contact and separation of two or more materials. Static electricity is particularly hazardous where the potential difference can generate sparks of sufficient energy to cause ignition or explosion of an ignitable mixture. Common sources of static electrical buildup in industry are:
- the transfer of nonconductive liquid through pipes, creating a charge on the liquid’s surface;
- steam, air, or gas flowing through an opening in a pipe or hose;
- finely divided matter transferred by chutes or conveyors;
- belts on motors and generators; and
- vehicles in motion.
The effect of static charges depends on the materials involved. In most cases the result is minor, such as the shock you get from putting a key in a lock after you slide across the car upholstery. But that same amount of electricity can destroy computer data. The energy generated from a static spark is generally not enough to cause personal injury, but it can ignite kindling, which is easily ignited with low energies. Such kindling includes flammable dust, flammable gases, and vapors from flammable liquids. In atmospheres that contain these types of kindling, static electricity sparks pose a serious potential hazard.
FIRE LOSS MANAGEMENT
UNFRIENDLY CAUSES OF FIRE
One precaution you can take is to provide a system of grounding that assures the electrical charge is dissipated and thus cannot jump across an air gap between two points. Jumping across such a gap generates sufficient heat to ignite the kindling. Providing adequate grounding requires initial technical knowledge and continual maintenance.
Some years ago, chains were dragged under gasoline trucks to try to dissipate the static charge that had been generated as the truck rolled. In at least one instance in which this technique was used, leaking gasoline running down a chain ignited from the metallic sparks generated as the chain dragged over the concrete. The best procedure is to make sure the truck is thoroughly grounded before discharge of cargo.
In certain production situations the static electricity is discharged by ionization. Gas flames or radioactive sources provide ionization. This creates an electrical path through the air, discharging the electricity to the ground.
Moist air is a good conductor of electricity. It provides for the discharge of static electricity before it builds to dangerous potential levels. In certain processes the entire operation is enclosed and the humidity is raised to 60 or 70 percent to provide for adequate electrical leakage. The fact that it is difficult to build up a static electrical charge in areas of controlled humidity has led to some serious accidents in areas that are dry. Personnel accustomed to handling flammable liquids under humid conditions who were transferred to areas where the air was dry discovered disastrously that handling practices that are safe in humid areas may cause real trouble in dry areas. (For a full discussion, see Section 12, Chapter 10 of the NFPA’s Fire Protection Handbook, 16th Edition; for a discussion of the hazards of static electricity, especially static-proof protective clothing, see “Static Electricity” by Larie Meal, Ph.D., in the May 1989 issue of Fire Engineering.)
(Photos by author.)
ARSON
Arson is one of the most serious causes of fire. It is extremely hard to detect and even harder to prosecute. Many fires first attributed to other causes are, in fact, incendiary. It is called by many a despicable crime because the arsonist completely disregards the potential consequences of his destructive actions.
We must distinguish between the pathological firesetter, who starts the fire because he is mentally or emotionally disturbed, and the arsonist who in his right mind sets fires to gain some desired end. The desired end may be defrauding an insurance company, destroying evidence of another crime such as embezzlement or inventory shortages, destroying property so it will be replaced with better and more modern equipment, extending the life of a construction job, or putting a competitor out of business. (For a complete account of an intricate commercial arson case, which was broken by topflight firefighting and a thorough investigation, see my article “History Still Holds Its Lessons: The Dachis Case” in Fire Engineering, January 1986.)
FIRE LOSS MANAGEMENT
UNFRIENDLY CAUSES OF FIRE
Pathological firesetting, on the other hand, may be a manifestation of a sociopathic personality or may be incidental to a pattern of rioting, looting, and destruction. The distinctions here are not intended to be absolute but rather to establish the difference between arson for an irrational purpose and arson for financial gain. Commercial fires have often been set to look like the work of a random arsonist.
There are two popular myths: There is no defense against the incendiary fire, and any rapidly spreading fire must be incendiary. Neither one is necessarily true.
One important defense against an incendiary fire is to thoroughly and completely investigate every fire that occurs. Every fire has a cause. While it may not be possible to determine the cause, if a fire is incendiary, a thorough investigation might affect the individual responsible for the fire—he may be frightened enough of getting caught that he discontinues his dangerous hobby. A thorough investigation is a preventive measure against repeated arson.
Another avenue of attack is to strike at the kindling used by the incendiary. Some arsonists bring a flammable liquid with them to start a fire, but very often they improvise—bringing only a match and starting the fire wherever kindling is available. Removing kindling may stop the arsonist altogether or at least deter him from setting the fire in your jurisdiction. Unguarded buildings open to the public should be inspected even more frequently to prevent kindling buildup.
Be sure to report even the smallest fire. Too often after a disaster we learn that there had been a series of incendiary fires “of no consequence” in the building that people on the premises extinguished and didn’t bother to report.
Fire departments and fire investigators should have at least an adequate knowledge of the subject and of the rules of evidence so that if a case ensues, prosecution will not be hampered by the mishandling or destruction of necessary physical evidence or by improper questioning of suspects. Management at institutions such as schools and hospitals is often reluctant to admit an arsonist may be on staff but must allow an investigation to proceed as objectively as possible. In too many instances on record a person desiring praise for discovering or extinguishing the fire is the one who actually started it; thus the adage, “The first person to question in a suspicious fire is the person who transmitted the alarm.”
