On-Scene Characterization of Flammable Liquid Vapors

ON-SCENE CHARACTERIZATION OF FLAMMABLE LIQUID VAPORS USING GC/MS AND SPME SAMPLING

J.D. DeHaan, Ph.D Fire-Ex Forensics Inc. USA
David A. Matthew, M.A. International Association of Fire Chiefs, USA
and
Gareth S. Dobson. Ph.D. Smiths Detection Inc. USA

Presented at International Symposium on Fire Investigation, 2014

ABSTRACT
There has not been a significant advancement in on-scene forensic fire debris analysis in over a decade. The ability to identify an accelerant at the fire scene would provide the fire investigator useful data, increasing efficiency and effectiveness. This research project was intended to establish if the identification of ignitable liquids can be achieved at the fire scene. Three testing sites in Utah, Texas and California provided data that the hand portable Gas Chromatography Mass Spectrometry (GC/MS) with Solid Phase Microextraction (SPME) fiber sampling technique is able to confirm the identity of ignitable liquid vapors at the fire scene consistent with fire debris analysis techniques. Post flashover testing was conducted at three sites in California and one in Utah providing replicable data confirming ignitable liquid vapor identification at low part per billion (ppb) and part per million (ppm) concentrations in real-world fires. The evidentiary samples taken at the testing sites in California were sent to a certified lab to confirm the results from the field data. The GUARDION ® GC/MS produced by Smiths Detection was used for field testing. A limiting factor in the field application of GC/MS was determined when the data produced had to be analyzed by a GC/MS specialist to confirm the identification of the ignitable liquid, similar to current laboratory techniques. It is recommended that a fire debris analysis method be developed to increase the field application of GC/MS.

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Fire Investigator Qualifications Standard Approved for OSAC Registry

NAFI has endorsed National Fire Protection Association (NFPA) 921 Guide for Fire and Explosion Investigations since the first edition was released in 1992. NFPA 921 has been a key source of technical information concerning the investigation of Fires and Explosions.  NAFI has also utilized and supported NFPA 1033 Professional Qualifications for Fire Investigators as this document provides guidance concerning the knowledge and competencies that a Fire and Explosion Investigator must have to effectively complete and investigation. Having these two documents selected and approved to be included in the Organization of Scientific Area Committees (OSAC) for Forensic Science registry which serves as a trusted repository of high-quality, science-based standards and guidelines for forensic practice is testimony that these documents are truly authoritative. Both of these documents have been key elements in the development and continuation of the NAFI Certified Fire and Explosion Investigator (CFEI) and Certified Vehicle Fire and Explosion Investigator (CVFI) programs. – Ron Hopkins, President, NAFI

The Organization of Scientific Area Committees (OSAC) for Forensic Science has approved the National Fire Protection Association (NFPA) Standard for Professional Qualifications for Fire Investigator for inclusion on the OSAC Registry, which serves as a trusted repository of high-quality, science-based standards and guidelines for forensic practice. This is the first personnel qualification standard and the second NFPA document to be included on the OSAC Registry.

OSAC, which is administered by the National Institute of Standards and Technology (NIST), is working to strengthen forensic science by facilitating the development of discipline-specific, science-based standards and guidelines for a broad array of forensic disciplines. To be posted to the OSAC Registry, standards and guidelines must have been developed using a consensus-based process and must pass a review of technical merit by forensic practitioners, academic researchers, statisticians and measurement scientists. Continue Reading…

Source: NIST.gov


1906, Dec 6th:  Monongah coal mine disaster

In West Virginia’s Marion County, an explosion in a network of mines owned by the Fairmont Coal Company in Monongah kills 361 coal miners. It was the worst mining disaster in American history.

In 1883, the creation of the Norfolk and Western Railway opened a gateway to the untapped coalfields of southwestern West Virginia. New towns sprung up in the region virtually overnight as European immigrants and African Americans from the south poured into southern West Virginia in pursuit of a livelihood from the new industry.

By the late 19th century, West Virginia, now a national leader in the production of coal, fell far behind other major coal-producing states in regulating mining conditions. In addition to poor economic conditions, West Virginia had a higher mine death rate than any other state. Nationwide, a total of 3,242 Americans were killed in mine accidents in 1907. In ensuing decades, the United Mine Workers of America labor union and sympathetic legislators forced safety regulations that brought a steady decline in death rates in West Virginia and elsewhere.

Source: History.com


A Study of Calcination of Gypsum Wallboard

Christopher L. Mealy
Daniel T. Gottuk
Hughes Associates, Inc.

Presented at International Symposium on Fire Investigation, 2012

ABSTRACT

The prevalence of gypsum wallboard in fire scenes makes it a potentially valuable source of information to fire investigators when assessing a fire scene. The exposure of gypsum wallboard to heat from a fire can result in calcination, which in turn can theoretically be correlated to the total heat exposure to that area. Therefore, if properly characterized, a calcination depth profile of a given enclosure could provide fire investigators with a detailed history of the total heat exposure to the walls and ceiling of the space. This history, when combined with other findings, could provide valuable insight as to where the area of origin was located or how the fire developed. The approach taken in this work incorporated small- and full-scale testing to accomplish several goals: 1) develop an objective method for measuring the calcination depth of gypsum wallboard, 2) assess the utility of the calcination depth surveys in full-scale fires, and 3) characterize the impact of suppression water on calcination depth measurements. In this work a probing pressure of 0.86 kg/mm2  (1175 psi) was identified as providing accurate calcination depth measurements. The benefit of calcination depth surveys in full-scale enclosure fire scenarios was realized primarily for cases where visual patterns were not obvious. The application of water to calcined GWB was found to alter the measured depth of calcination by an average 18 percent, when collected 24 hours after heating/water application and less than five percent after 30 days. This data suggests that if measurements are to be collected in areas that have been wetted by suppression activities for any extended period of time, it would be advisable to delay measurements until the water has been removed.

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1968, Nov 20th:  Explosions rock West Virginia coal mine

Methane gas explosions in a West Virginia coal mine kill 78 men on November 20th, 1968. The damage to the mine was so extensive that it had to be sealed with the bodies of the men still inside.

The Consol No. 9 mine was located about 10 miles from the town of Monongay, between Farmington and Mannington in West Virginia. It was a large mine, approximately eight miles by six miles, with untapped oil and natural gas below the coal. At midnight on November 20, the workers descended 600 feet below the earth’s surface to begin the night shift. At 5:40 a.m., a large explosion was quickly followed by three smaller ones. The blasts were so powerful that the lamphouse near the entrance to the mine was demolished.

Twenty-one men working in one section of the mine were able to escape in the early morning light even though dense smoke continued to billow from the nine entrances for hours. As rescue and relief workers arrived on the scene, it was unclear how many men remained in the mine, as the list of late-shift workers had been stored in the now-destroyed lamphouse. Since it was still impossible to enter the mine, the rescuers surveyed the families of the mine workers to get a complete list of the trapped miners.

At 10 p.m., as the would-be rescuers waited for an opportunity to enter the mine, there was another explosion; yet another occurred overnight. Given that the mine had only two working ventilators and the fire continued to burn, it became clear that it was unlikely the mine workers were still alive. Furthermore, the only way that the fire, smoldering in the coal deposits, could be extinguished was to cut off its air supply, which would suffocate any survivors. It was decided to drill a hole down to the area of the mine that was the only possible location of survivors.

When there was still no indication of life 10 days after the explosions first ripped through the mine, it was decided to seal the mine completely, with the 78 victims still buried inside it.

Source: History.com


Scientific Method-Use, Application, and Gap Analysis for Origin Determination

 

Gregory E. Gorbett, MScFPE, CFEI, IAAI-CFI, CFII, CFPS
Eastern Kentucky University, USA
and
Wayne Chapdelaine, CFEI, IAAI-CFI, CFII
Metro-Rural Fire Forensics

Presented at International Symposium on Fire Investigation, 2014

ABSTRACT
The fire investigation industry is considered to be lagging behind the rest of the forensic science fields in its assessment of the performance of methodological approaches and conclusions drawn by practitioners within the field. Despite the best efforts of certifying bodies and industry members, there are still many unknowns within the profession. This paper will present practical uses of the scientific method as it relates to Origin Determination. Several recommended practices have been identified and formatted to reflect the scientific method as utilized in NFPA 921. In addition, where practical, a gap analysis has been conducted on these processes with recommendations provided.

Download the complete paper here


Great Boston Fire of 1872 – November 9, 1872

On November 9th in 1872, a fire in Boston destroyed hundreds of buildings and killed 14 people. In the aftermath, the city established an entirely new system of firefighting and prevention. The fire also led to the creation of Boston’s financial district.

The fire began in the basement of a warehouse at the corner of Kingston and Summer streets. At the time, this area of the city contained a mix of residences and light industry. Its buildings and most area roofs were made mainly of wood, allowing the blaze to spread quickly as the wind blew red hot embers from rooftop to rooftop. In addition, as Boston streets were narrow, large flames from one structure could literally leap across them to nearby buildings.

Firefighting units from Maine to New Haven, Connecticut, arrived to help, but efforts to fight the fire were plagued by difficulties. There was not enough water on hand to get the fire under control; the hydrant system did not work well because much of the equipment was not standardized; and even when firefighters got their hands on an adequate supply of water, the height of the buildings and the narrowness of the streets made it difficult to direct the water at the blaze from the optimum angle. Because a local equine epidemic had struck the city fire department’s horses, it was difficult to get the fire engines to the correct locations at the right times. In addition, some of the efforts were counter-productive. Explosions were used to attempt fire breaks, but this high-risk strategy was not executed with enough precision and served only to further spread the fire.

The fire was finally stopped at the doors of Fanueil Hall the following morning, but it had already destroyed much of the downtown area. Boston’s officials realized that their fire-prevention efforts had been ineffective and, in the aftermath of the disaster, began to revise and strengthen all of the city’s fire laws and regulations. An inspection system was instituted and the local fire departments began to coordinate their efforts.

The fire also helped fuel Boston’s growth. The business community saw the burned area as an opportunity to expand its presence downtown. The city’s financial district was established where the fire had hit hardest and Boston soon became a key business center of the late 19th-century United States.

Source: History.com
Photo Source: Wikipedia.com


Fires Originating in Branch-Circuit NM Cables Due to Installation Damage

Vytenis (Vyto) Babrauskas, Ph.D.
Fire Science and Technology Inc., Issaquah WA

Presented at International Symposium on Fire Investigation, 2014

ABSTRACT
A significant fraction of US structure fires originate in electrical wiring, and there is also reason to believe that these numbers may be systematically undercounted. The role of voltage surges and damaged insulation in creating the potential for fire is discussed. That damaged electrical insulation may lead to fire has been known for a century, yet details of the mechanisms by which this occurs have not been extensively studied. UL recently published a study on damage due to poor workmanship in stapling of cables, specifically cases where the insulation is damaged but the conductors are not split. This study establishes that damage which may not appear visually striking may result in dielectric failure; such failures can be a direct cause of fire. Case histories are presented illustrating how mechanical damage associated with stapling of NM cables can result in serious fires. Two preventive measures are described: (a) installation by use of staplers and not hammers, and (b) testing the dielectric withstand voltage of branch circuits after installation and prior to energizing. Both of these measures, if implemented, should reduce the prevalence of electrical fires. However, given the immense amount of fixed wiring installed in buildings, fires due to damaged insulation do not imply that current wiring methods are a low-reliability technology. Only when serious installation defects are present does fire become a foreseeable event.

Keywords : dielectric strength of cables; electrical fires; forensic failure analysis; electrical installation defects; NM cables; voltage surges.

Download the complete paper here


Industrial Incident Investigation Techniques

Thomas V. Rodante, P.E., CFEI, CFII
Baker Engineering and Risk Consultants Inc., USA

Presented at International Symposium on Fire Investigation, 2012

ABSTRACT
NFPA 921 provides an excellent framework for individuals charged with the responsibility of investigating fire and explosion incidents. NFPA 921 establishes systematic investigative and analytical scientific techniques around the core principle of scientific methodology. Guidance is provided in NFPA 921 to show and explain the process of evidence collection, analysis, hypotheses formulation, forensic hypotheses testing, hypothesis correction and re-testing, and final cause determination. This presentation provides case study examples, not offered within NFPA 921, of forensic scientific methodology as applied to industrial petrochemical processing incidents.

Specific potential industrial evidence types are discussed and examples provided. The use of a timeline spreadsheet beyond that explained in NFPA 921 is shown with examples of how to correlate process data to witness statements. A case study scenario supposition and hypothesis spreadsheet is provided to show an example method for organizing observations, list related hypotheses, determine forensic test criteria, and document results. The provided example includes scientific forensic use of flame and vapor dispersion modeling, and metallurgical analysis. Finally, an example fault tree is shown as an alternative analytical method for cases in which the existence of physical evidence may be limited.

Download the complete paper here


October 7, 1871: Most Devastating Fire in US history

The most devastating fire in United States history is ignited in Wisconsin on October 7th, 1871. Over the course of the next day, 1,200 people lost their lives and 2 billion trees were consumed by flames. Despite the massive scale of the blaze, it was overshadowed by the Great Chicago Fire, which began the next day about 250 miles away.

Peshtigo, Wisconsin, was a company lumber and sawmill town owned by William Ogden that was home to what was then one of the largest wood-products factories in the United States. The summer of 1871 was particularly dry across the northern Midwest. Still, settlers continued to set fires, using the “slash and burn” method to create new farmland and, in the process, making the risk of forest fire substantial. In fact, the month before had seen significant fires burn from Canada to Iowa.

Peshtigo, like many Midwestern towns, was highly vulnerable to fire. Nearly every structure in town was a timber-framed building–prime fuel for a fire. In addition, the roads in and out of town were covered with saw dust and a key bridge was made of wood. This would allow a fire from outside the town to easily spread to Peshtigo and make escaping from a fire in the town difficult. On September 23, the town had stockpiled a large supply of water in case a nearby fire headed in Peshtigo’s direction. Still, they were not prepared for the size and speed of the October 7 blaze.

The blaze began at an unknown spot in the dense Wisconsin forest. It first spread to the small village of Sugar Bush, where every resident was killed. High winds then sent the 200-foot flames racing northeast toward the neighboring community of Peshtigo. Temperatures reached 2,000 degrees Fahrenheit, causing trees to literally explode in the flames.

On October 8, the fire reached Peshtigo without warning. Two hundred people died in a single tavern. Others fled to a nearby river, where several people died from drowning. Three people who sought refuge in a water tank boiled to death when the fire heated the tank. A mass grave of nearly 350 people was established because extensive burns made it impossible to identify the bodies.

Despite the fact that this was the worst fire in American history, newspaper headlines on subsequent days were dominated by the story of another devastating, though smaller, blaze: the Great Chicago Fire. Another fire in Michigan’s Upper Peninsula that consumed 2 million acres was an even smaller footnote in the next day’s papers.

Source: History.com