Information Analysis for Fire Protection
In general terms, fire science has only recently been developed to a stage at which it is capable of providing the knowledge base on which rational decisions regarding engineering design, including safety issues, can be based. Traditionally, fire safety has developed on an ad hoc basis, effectively responding to incidents by imposing regulations or other restrictions to ensure that there will be no re-occurrence. Many examples could be quoted. For example, the Great Fire of London in 1666 led in due course to the establishment of the first building regulations (or codes) and the development of fire insurance. More recent incidents, such as the high-rise office block fires in São Paulo, Brazil, in 1972 and 1974, initiated changes to the building codes, framed in such a way as to prevent similar multiple-fatality fires in the future. Other problems have been addressed in a similar fashion. In California in the United States, the hazard associated with certain types of modern upholstered furniture (particularly those containing standard polyurethane foam) was recognized, and eventually strict regulations were introduced to control its availability.
These are simple cases in which observations of the consequences of fire have led to the imposition of a set of rules intended to improve the safety of the individual and the community in the event of fire. The decision for action on any issue has to be justified on the basis of an analysis of our knowledge of fire incidents. It is necessary to show that the problem is real. In some cases—such as the São Paulo fires—this exercise is academic, but in others, such as “proving” that modern furnishings are a problem, it is necessary to ensure that the associated costs are wisely spent. This requires a reliable database on fire incidents which over a number of years is capable of showing trends in the number of fires, the number of fatalities, the incidence of a particular type of ignition, etc. Statistical techniques can then be used to examine whether a trend, or a change, is significant, and appropriate measures taken.
In a number of countries, the fire brigade is required to submit a report on each fire attended. In the United Kingdom and the United States, the officer in charge completes a report form which is then submitted to a central organization (the Home Office in the United Kingdom, the National Fire Protection Association, NFPA, in the United States) which then codes and processes the data in a prescribed fashion. The data are then available for inspection by government bodies and other interested parties. These databases are invaluable in highlighting (for example) the principal sources of ignition and the items first ignited. An examination of the incidence of fatalities and their relationship to sources of ignition, etc. has shown that the number of people who die in fires started by smokers’ materials is significantly out of proportion with the number of fires which originate in this way.
The reliability of these databases depends on the skill with which the fire officers carry out the fire investigation. Fire investigation is not an easy task, and requires considerable ability and knowledge—in particular, a knowledge of fire science. The Fire Service in the United Kingdom has a statutory duty to submit a fire report form for every fire attended, which places a considerable responsibility on the officer in charge. The construction of the form is crucial, as it must elicit the required information in sufficient detail. The “Basic Incident Report Form” recommended by the NFPA is shown in the Fire Protection Handbook (Cote 1991). The data can be used in two ways, either to identify a fire problem or to provide the rational argument necessary to justify a particular course of action that may require public or private expenditure. A long-established database can be used to show the effects of actions taken. The following ten points have been gleaned from NFPA statistics over the period 1980 to 1989 (Cote 1991):
1. Home smoke detectors are widely used and very effective (but significant gaps in the detector strategy remain).
2. Automatic sprinklers produce large reductions in loss of life and property.
3. Increased use of portable and area heating equipment sharply increased home fires involving heating equipment.
4. Incendiary and suspicious fires continued to decline from the 1970’s peak, but associated property damage stopped declining.
5. A large share of fire-fighter fatalities are attributed to heart attacks and activities away from the fireground.
6. Rural areas have the highest fire death rates.
7. Smoking materials igniting upholstered furniture, mattresses or bedding produce the most deadly residential fire scenarios.
8. US and Canadian fire death rates are amongst the highest of all the developed countries.
9. The states of the Old South in the United States have the highest fire death rates.
10. Older adults are at particularly high risk of death in fire.
Such conclusions are, of course, country-specific, although there are some common trends. Careful use of such data can provide the means of formulating sound policies regarding fire safety in the community. However, it must be remembered that these are inevitably “reactive”, rather than “proactive”. Proactive measures can only be introduced following a detailed fire hazard assessment. Such a course of action has been introduced progressively, starting in the nuclear industry and moving into the chemical, petrochemical and offshore industries where the risks are much more easily defined than in other industries. Their application to hotels and public buildings generally is much more difficult and requires the application of fire modelling techniques to predict the course of a fire and how the fire products will spread through the building to affect the occupants. Major advances have been made in this type of modelling, although it must be said that there is a long way to go before these techniques can be used with confidence. Fire safety engineering is still in need of much basic research in fire safety science before reliable fire hazard assessment tools can be made widely available.