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FIRE RESEARCH. Recommendations of The Research Advisory Council on Post-fire Analysis. A White Paper FIRE PROTECTION RESEARCH FOUNDATION



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Recommendations of The Research Advisory Council on Post-fire Analysis A White Paper THE FIRE PROTECTION RESEARCH FOUNDATION ONE BATTERYMARCH PARK QUINCY, MASSACHUSETTS, USA THE FIRE PROTECTION RESEARCH FOUNDATION FIRE RESEARCH Copyright The Fire Protection Research Foundation February 2002 FOREWORD This White Paper has been developed by the Research Advisory Council on Postfire Analysis, a nationwide panel of experts in fields related to post-fire analysis, and other interested parties in industry and government. The fields of expertise brought to the Council include fire data analysis, fire prevention and suppression, fire research and testing, product safety and testing, insurance, education, chemistry, criminal investigation -- as well as fire origin and cause investigation. The Council s mission is to meet regularly to review the state of the art and science of post-fire analysis, and -- as desired -- to make recommendations for further documentation, research and development. The Council s mission does not include making proposals to standards or regulations, participation in fire investigations, or carrying out the recommendations. It is rather to convene world-respected experts under an independent imprimatur, and thus to give its recommendations the greatest leverage. As one Council member said, We will give our best to these, and then it s up to the stakeholders. Our role is to hold your coat. Thus, the Council organized its recommendations into cogent cases for needed work in five areas, and determined to synthesize them into a single White Paper. The Council next intends to generate a white paper on post-fire analysis and fire s environmental impacts, and one on post-fire analysis and business impacts, expanding on recommendations included in brief form here. The Research Foundation convened the Council in 1998, one of seven international councils with similar missions in the areas of fire toxicity; fire detection futures; fire suppression futures; performance-based fire safety; aqueous film forming foams; and the NFPA 262 wire & cable fire test. Other councils are planned. Council members and the Foundation are extremely grateful to Richard L.P. Custer, MSc., CFEI, for his diligence in capturing the Council s ideas in the several drafts that they have reviewed. The Foundation thanks Council members for their contributions of time and the resources to produce this work, making it available on request, free of charge. In fact, the reader is encouraged to contact any of the Council members for a greater understanding of the information, expertise and passion for improved post-fire analysis represented here. Research Advisory Council on Post-fire Analysis Frank Borrelli The Vinyl Institute George Capko FM Global William Carroll Occidental Chemical Corporation Daniel Churchward Kodiak Enterprises, Inc. Richard Custer ArupFire USA Joseph Fleming Boston Fire Department Herman Hall The Vinyl Institute John Hall NFPA James Hoover E.I. dupont de Nemours & Co., Inc. Patrick Kennedy John A. Kennedy and Associates/ National Association of Fire Investigators William King, Jr. U.S. Consumer Product Safety Commission William Metes Underwriters Laboratories Inc. H. Patrick Toner The Society of the Plastics Industry Richard Tontarski U.S. Bureau of Alcohol, Tobacco and Firearms Recommendations of The Research Advisory Council on Post-fire Analysis A White Paper I. Introduction This is the first report on the Post-fire Analysis Research Advisory Council s deliberations. It reviews the status of the techniques and knowledge base of post-fire investigations, and presents recommendations addressing the research and development needs that the Council has identified. Post-fire analysis comprises a wide range of activities. It aims to identify where and how a given fire or group of fires started and the factors contributing to fire loss. The collected knowledge can be applied to reduce the future costs of fire in terms of casualties, property damage and building regulations. Traditionally, most post-fire-analysis effort has been focused on the origin and cause of fires with emphasis on civil and criminal litigation. Most of the resources have been directed to investigation of fires with large financial or human losses. Often these major investigations take place well after the fire authorities have assigned a cause. In some instances, further investigation results in differing theories regarding cause. Despite extensive investigation, data collected nationally rarely include details relating to the reasons for extensive loss or successful control. Instead information is comprised mainly of reporting by the fire authorities. Statistics used as the basis for developing or changing building codes or selecting targets for fire protection programs frequently are inadequate. Cause is identified by establishing the ignition source, the fuel ignited and the factors that brought them together. Causes are characterized as natural, unintentional, incendiary and unknown/undetermined. Many techniques used to determine cause are based upon the interpretation of damage patterns such as wood char morphology and depth, manner of glass breakage, and nature of smoke deposits. The color of smoke and the apparent speed of fire growth are also used to infer causal relationships. Today s situation exists because the basis for identification of fire origin and cause has evolved from practical knowledge rather than scientific research. Over the past decade, however, the development of better understanding of fire science and factors related to fire growth and spread has led many investigators 1 to question these empirical techniques. In 1992, the first edition of NFPA 921 Guide to Fire and Explosion Investigation 1 was issued. The NFPA Technical Committee on Fire Investigations reviewed the bases for a number of traditional interpretations of fire scene evidence, including: Large shiny char blisters indicate fast fires and the presence of ignitable liquids. Small, flat and dull blisters characterize slow accidental fires. The angle of slope of the sides of a V pattern on a vertical surface suggests the intensity of the fire. Spalled concrete floor slabs are definitive of an ignitable liquid fire. Depth of char determines time of fire initiation. Dark or black smoke or rapid fire growth indicates the presence of ignitable liquids. A salient finding of NFPA 921 is that patterns seen following fires can result from more than one set of conditions and thus may not indicate any one cause exclusively. Thus, NFPA 921 recommends a formalized approach to fire origin and cause investigation utilizing the scientific method of data collection, hypothesis development and hypothesis testing. Testing carried out at the National Institutes for Standards and Technology (NIST) validated this approach. It demonstrated that fire patterns can, in fact, have multiple sources NIST investigated these fire patterns in the light of some basic liquid accelerant and room fire scenarios. Many more variables that can affect evidence at fire scenes have yet to be investigated, including effects of burn time, materials involved, ventilation and fire fighting techniques. Prima facie evidence previously used is now deemed inadequate or inconclusive; however, new methods and technologies have not yet evolved to aid in fire scene investigation. National fire statistics can give a general picture of the factors affecting fire losses but may not provide sufficient detail to assess adequately the effectiveness of specific fire code requirements. For example, statistics alone cannot determine the effect of regulation of combustibility of interior finishes on fire losses. Advantages of automatic sprinklers versus fire-rated construction can only be evaluated in broad terms. This is particularly true when fire resistance has been reduced because of the use of automatic sprinklers. Additionally, effects of specific fire protection designs used cannot be assessed since design and performance details are sparsely reported. These questions must be answered if we are to develop more cost-effective building regulations and evaluate the effects of performance-based design. For the most part, the successful performance of fire protection features may be 2 under-examined in fire investigations since it can result in fires too small to report to the fire department or even to the insurance companies. These fires might not be investigated at all. In November 1997 the federal Bureau of Alcohol, Tobacco and Firearms sponsored the International Conference on Fire Research for Fire Investigation 5 that bought together national and international fire researchers and fire investigators to identify the current state of the art and technical gaps in fire investigation. The conference issued a Proceedings identifying research and development needs. Among the cited research and development needs included: Fire incident reconstruction -- laboratory methods for testing of ignition source hypotheses Validation of pattern analysis patterns on walls and ceilings and patterns resulting from liquids on floors Determination of burning rates for different items and development of a burning rate data base Means to validate identification of electrical faults as an ignition source Impacts of flashover on fire patterns and other indicators Effects of ventilation on fire growth and origin determination Validation of fire models Fire investigator occupational health and safety Training and education needs included: Specific training in understanding fire patterns, use of models Protocols for collection of data at the fire scene Training and certification for laboratory personnel Certification programs for investigators Methods and means for training the trainers A full list of all the identified needs is reported in the conference Proceedings. 3 II. Discussion To organize the discussion, the Research Advisory Council has identified five broad areas where progress is needed in post-fire analysis. These are: Origin and Cause Investigation Methods Deaths, Injuries, Property Losses and Building Costs Education, Training and Dissemination Environmental Impacts of Fire and Fire Protection Business Impacts The first area relates to cause determination. The second addresses post-fire analysis methods to assess the effectiveness of codes, standards and fire safety design on controlling fire losses. Education and training are needed to raise the awareness and capability of post-fire investigators. The two other identified areas are nontraditional, but becoming more visible. Fire is now recognized as an event in the open environment: Smoke impacts air. Runoff impacts water. Finally, consumer confidence and tenant concern about fires in tall buildings might affect the construction and rental market. This is an unobvious impact of fire on business. The issues associated with these last two areas will be introduced in this document but are sufficiently broad based and complex that they will be the subjects of more detailed study in a subsequent white paper. For each of these areas, the following topics will be addressed: Problem a general statement of the problem(s) associated with postfire analysis Impact identification of potential impact of advances in specific problem areas Research and Development needs and recommendations Stakeholders identification of those groups most likely to benefit from advances 4 III. Recommendations Origin and Cause Investigation Methods Problem: There is a lack of scientific foundation for many methods used to identify the area of origin and the cause of fires. The interpretation of patterns can be extremely difficult due to the complicated effects of the type and form of the materials burning, the building geometry and ventilation and the fire fighting actions taken. This can lead to confusion and conflicting indications. Two investigators may have different causal theories based on observation of the same patterns. In those cases where the extent of fire development is limited to one room or perhaps one or two items, the location of the point of origin may be obvious by observation of the fire damage patterns. At the other extreme is found the massively destroyed fire scene often referred to as a black hole. In this case, the investigator sees patterns that represent the summation of all the damage for the duration of the fire and the overhaul or final extinguishment phase of the fire department operations and it may be impossible to determine the order in which the patterns evolved. In between lies a continuum where the value of patterns decreases as that magnitude and duration of the fire increases. If patterns are to be used for origin and cause determination, forensic methods to identify the specific source of a pattern need to be developed and rigorously vetted. This can be particularly important for identifying patterns caused specifically by burning ignitable liquids or other incendiary materials where potential arson is at issue. Impact: Two areas of potential major impact would be criminal litigation (for arson fires) and civil litigation (for product involvement in unintentional fires). In both cases, more detailed, more accurate and more confident determination of origin and cause should lead to more successful litigation of valid cases and less frequent initiation of invalid cases. Better procedures could also result in less disagreement on facts between investigators, which should lead to faster, less expensive resolution of cases. But all of this requires not just better procedures but also the broadest possible information dissemination, training, education, and certification. We need to have better ways to generate and use information, we need everyone to understand and use those better ways, and we need to know that they do. The quantitative impact is particularly clear for arson fires. In a typical year, arson is estimated to result in half a million fires reported to US fire departments and roughly $2 billion in direct property damage, together with hundreds of deaths. Roughly one-third of the fires are confirmed as incendiary, another one- 5 third are only categorized as suspicious (characteristics consistent with incendiarism but no positive determination), and the other one-third are the arson share of fires with no cause determined at all. Only the one-third confirmed as incendiary go on to police investigation, and only one-sixth of that group leads to an arrest. Better origin and cause determination would be expected, therefore, to triple the number of arson cases sufficiently documented to justify police investigation. Better origin and cause determination could very well provide enough additional forensic detail to improve the solve-by-arrest percentage, as well, and improve the percent of arrests that lead to conviction. At present, NFPA estimates that only 2% of set fires lead to a conviction 6, and every step in the investigative process offers opportunities to greatly improve that percentage through better forensic procedures. Improved methodologies for origin and cause determination would also provide greater confidence, and possibly greater quality, in statistics on fire problems. Limited special studies have indicated that fire reports are subject to a substantial but unbiased error rate. That means there is a high rate of errors, but the errors favor no particular characterization, so the errors tend to cancel out when reports are aggregated for statistics. However, many professionals are more focused on some types of errors rather than others, and so remain concerned about the high rate of errors per report and are distrustful of statistics from such a database. Reducing the rate of errors, therefore, will provide greater confidence in statistics, both by reducing the statistical uncertainty associated with the error rate and, perhaps more importantly, by reducing the perception of inaccuracy. Any resulting changes in statistical patterns would result in greater quality as well, but the improvement in confidence would be very valuable, even if the statistical patterns are largely unchanged. Data exists on actual ignition and fire performance of many major product types, but not specific brands or functional design types. Even when identified and reported to the Consumer Product Safety Commission or similar agency, which is rare, the data is not available for general use. In addition, much product fire testing focuses on standard tests that may not reflect the full range of end-use configurations or applications. Improved data can help identify specific problems with materials, products or test methods. An example of how this can work is found in the case of halogen torchier lamp fires involving curtains and drapes that resulted in revised requirements to UL Standard 153 Portable Electric Lamps 7. Stakeholders: Improved origin and cause determination particularly affects the law enforcement, fire fighter and insurance communities. For law enforcement, better and more rigorous methods can result in higher arson conviction rates. The fire fighter community benefits from improved product safety and a better understanding of performance in fire, which translates to improved fire fighter 6 safety. For the insurance community, the outcome would be reducing losses by having a stronger basis for pursuing arson/fraud and subrogation activities. Improved origin and cause determination affects those writing fire prevention regulations by providing a better basis for targeting regulations and for inspection and public education programs. Improved origin and cause determination also affects writers of building codes, in that fire scenarios involving specific functional areas of buildings, or specific occupancies, could be identified and reflected in code development. Research and Development Needs: Developing the experimental data to resolve these problems can be extremely expensive due to the large number of variables involved and the costs associated with the needed large scale testing. For this reason, very specific research targets need to be identified with potentially high return. In order to accomplish this high cost effort, it will most likely be necessary to share the costs among stakeholders. Since knowledge of the origin of a fire is, in nearly all cases, essential to determining cause, a high priority should be placed on new or improved methods for identifying the point or area of origin including burn pattern analysis. Such new or improved methods should be developed, peer reviewed and published to meet the challenges of the recent court tests under the Daubert 8 and Kuhmo Tire 9 rulings. These rulings have tightened the requirements for both scientific and technical data used as evidence, and the opinion basis of expert testimony. Both these rulings have come into play as tests of the admissibility of evidence and opinions in fire litigation. Methods for analyzing burn patterns concerning their meaning in the early growth history of the fire are also important. In particular, how does one determine when in the course of the fire event a particular pattern was made and how it might relate to a given potential ignition scenario? One possible approach would be to study from an engineering/combustion perspective the top 10 incendiary ignition scenarios and determine whether there are separate characteristics or groups of characteristics that are unique to a given scenario. Research also needs to address the effects of ventilation and airflow, either natural or induced by fire fighting activity, on fire patterns. Knowledge of ignition, early fire growth, flame spread and smoke generation as related to the genesis of fire patterns needs to be developed and integrated into the models being used to interpret fire patterns and test origin and cause theories. Methods should be ex
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