Fire Investigation Cigarettes: How Often They Cause Fires - Example

Fire Investigation Name: Lecturer: Course: Date: The widespread prevalence of smoking as well as the general opinion as to its propensity to cause fires in various situations has resulted in it being noted as the probable fire cause in situations where it is totally inappropriate. Discuss Introduction The prevalence of smoking and its proclivity for causing fires under complex circumstances has made it a key subject of review. Indeed, poorly discarded cigarettes can cause fire accidents and injuries in situations and places where it is inappropriate. Based on this premise, smoking is considered a leading cause of fatal yet preventable fires and deaths (Baker 2006). Indeed, statistics show that some 1000 victims of fires each year are smokers who fell asleep while sleeping. Based on these, this essay examines the circumstances under which a cigarette can start a fire and situations where cigarettes may be discarded in homes. Also examined include reasons why cigarette ignite or cause fire and the heat profile of cigarette such as the heat release and the ash. Circumstances under which a cigarette can start a fire Poorly discarded cigarettes on upholstered furniture can cause fires under a range of circumstances. Indeed, they are the leading cause of upholstered furniture fire (Fig 1). A study by National Fire Protection Association’s (NFPA) in the period 2005- 2009 found that upholstered furniture was the main item started by fires due to carelessly discarded cigarettes. The study showed that smoking remained the major cause of fires in upholstered furniture (NFPA 2011). In the period, smoking caused 28 percent of the fires on the furniture in addition to 58 percent of the associated deaths (Fig 1). Figure 1: Main causes of fire on upholstered furniture (NFPA 2011). Careless disposal of cigarettes is a prevalent cause of accident fires. A common scenario where such accidents occur is once they are discarded carelessly on ignitable materials. Indeed, cigarettes are deliberately manufactured to continue burning even when discarded until they are completely consumed (Tawadrous 2000). Because of this, they can burn through the mattress of cushion of a seat as a result starting fires that can smolder for long periods. Such hidden fires generate toxic gases that may make sleeping victims to become unconscious before the mattress or cushion bursts into full flame. At this stage, superheated air inside the room will reach flashover fast, threatening the safety of occupants of the room (Tawadrous 2000). The reason for this is that although cigarettes may appear like wrapped tobacco inside a paper, they are in actual fact designed to go on burning even when not puffed. This is to save smokers from the hassle of having to light up the cigarette again. However, it also implies that when a lit cigarette rolls onto upholstered furniture or mattress, smolders on the other hand can go undetected for nearly 30 minutes before they eventually burst into flames (Tawadrous 2000). The ignition of soft furnishing such as mattresses and upholstered furniture by smoldering cigarettes has been critical reviewed through empirical studies. A significant finding is that the ways in which cigarettes smolder on substrates is distinct from the ways in which cigarettes burn in air, when compared to the temperatures observable in air or free burning (Tawadrous 2000). After cellulosic cover or upholstery is ignited, heat from the smoldering substrate increases the temperature of the cigarette core (Nagao, Yamada & Horio, 2004). Other studies on the ways in which igniting substrates and cigarettes interact found that cigarettes with lower ignition propensity on some fabric upholstery were observed, even as the factors leading to lower ignition propensity still remain unclear. These show the potential damage under which discarded cigarettes can cause fatal fires. A report by the National Fire Protection Association (NFPA) shows that about 1000 deaths and some 3000 injuries in the United States each year result from fires ignited by cigarettes (Tawadrous 2000). The report further indicates that the source of ignition of 20 percent of fire deaths are materials smoldered by carelessly discarded cigarettes, with property loss of over US$500 billion each year. Additionally, the economic cost of productive labor, health care and the cost of human pain are estimated at US$4 billion (Nagao, Yamada & Horio, 2004). Situation where the cigarette maybe discarded in homes Discarding of cigarettes can happen under different situations. Common scenarios include when a smoker discards lit cigarette at the porch or front door while entering the house. Scenarios where such fires have been noted causing house fires occurred when the cigarette catches smoldering material (Anon 2013). In other scenarios, builders have also cause fires at home. A case in point is when a builder carelessly discarded a lit cigarette in a kitchen unit that spark a house a blaze in a home at Liverpool UK while working on the home’s driveway. An investigation by the Liverpool fire service team revealed that the slow smoldering fire was ignited accidently by a carelessly discarded cigarette that landed on a sofa (Pattinson, R 2014). In other scenarios, cigarettes discarded in bushes or landscaping surrounding homes by smokers who smoke on balconies are also responsible for fires that can cause havocs to an entire home. Indeed, a report by the Keizer Fire District in Oregon shows that the fire department responds to some 50 cases in the greater Salem area each week, where cigarette was discarded carelessly in landscaped vegetation that surround homes or vegetation (Trett 2002). According to the report, more residents do not smoke inside homes but on balconies or patios of their homes and when they are through they toss the cigarette into the drying grass or bark dust that surround their homes. The cigarette may then smolder for hours before igniting fires (Trett 2002). An additional scenario is where smokers toss cigarette butts from their vehicles and onto the roadways while driving. Such incidents have been noted in Oregon when a driver threw a cigarette from a window that hit the road before bouncing onto dry grass that surrounded a home causing huge fires that spread to the home (Trett 2002). Fire can also be caused when smokers discard the cigarettes carelessly onto cushions or carpet inside homes. In other circumstances, smokers may fall asleep while smoking. The cigarette may slip from the fingers onto the bed causing fires. Such scenarios have happened in Curtin Crescent in Melbourne, Australia when carelessly discarded cigarette inside a lounge room caused fire. The accident left one woman and two men dead. After the accident, Counter Fire Authority (CFA) estimated that carelessly lit cigarette caused the fire (Duncan & Turnbull 2008). Circumstances under which cigarettes ignite or cause fire Smoldering refers to flameless combustion that often occurs in cellulosic and other materials that can char. Smoldering may happen at very minimal concentration of oxygen spreading at a slow rate. Lit cigarette is an example of smoldering combustion. In a common scenario, heat from the burning combustion zone, which usually has a temperature of 600 degrees Celsius, burns adjacent to the tobacco as a result releasing pyrolysis and distillation products (Krasny 1987). When the combustion spreads along the cigarette, other compounds are released from the tobacco depending on the volatility of the compounds. The tobacco that glows becomes pure carbon. Once air is drawn into the cigarette, the combustion zone temperature increase increasing the rate at which the smolder spread along the cigarette. Once air flow is increased, flames result causing fires. In typical situations, fires with smoldering start off when they get into contact with finely divided cellulosic substances (Ermala, P & Holsti n.d.). The substances can smolder when the cigarette sustains heat. Examples of materials that can allow smolder to progress causing fires include upholstered furniture, baled cotton, hay, saw dust, corrugated board, latex form and cellulosic fabrics such as rayon and cotton. Circumstances under which discarded cigarette ignite materials Most homes are filled with substrate materials that will burn once ignited. These include clothing, upholstered furniture and mattresses. Flammable materials such as gasoline are also ignitable. Despite the fact that discarded cigarettes have been widely reported to be a cause of fatal fires, they can cause fires only under certain conditions of circumstances. In this case, cigarettes may not cause fires when conditions that support smoldering are not available (Trett 2002). For instance, when a cigarette lands on a carpet, it would in most cases merely cause a small burn that would not spread beyond the immediate location of the glowing end. In the same case, a cigarette that lands on a sheet of paper is not likely to generate fire except for the slight localized charring. Additionally, fire may not be caused in waste bins where crumpled papers are dumped. The reason for this is since it can only generate a small smoldering that can only last for a few minutes. However, absorbent tissues can smolder for longer periods of time (Nagao, Yamada & Horio, 2004). Additionally, glowing cigarette may not in normal cases ignite petrol vapor. Indeed, this has been proved through empirical studies. This is since the small value of the petrol’s upper flammability limit (5.9 percent) shows that high oxygen requirements for igniting the petrol vapor. In this case, in the presence of a glowing cigarette tip, insufficient oxygen is present to ignite petrol vapors (Nagao, Yamada & Horio, 2004). Heat profile of cigarette The features of the mainstream smoke are dependent on the rate at which tobacco beds burn. The manner in which cigarette combustion occurs has been investigated by different studies. Concerning the rate of heat generation and rate of heat distribution during puffing, the transient changes in the distribution of changes inside a burning cigarette can be classified into two periods (Ohlemiller 1995). The rate of heat generated increases at the initial stage of puffing before it significantly decreases during the unsteady period (Nagao, Yamada & Horio, 2004). Afterwards, stable heat occurs during the steady period of puffing. Second, the heat generation happens at the region that is adjacent to the paper char line at each stage. It then follows the movement of the paper char line. In particular, significant heat generation occurs at the region surrounding the paper char line at the unsteady period (Centers for Disease Control and Prevention 2010). Once the puffing rate is increased and the weight of the cigarette basis increases, the rate of heat generation throughout the unsteady period increases at the region that is at the rear of the paper char line. At this rate, the total heat generated during puffing is more than half of the total of that produced (Nagao, Yamada & Horio, 2004). The smoke emanating from the burning cigarette consists of intense aerosol of liquid particles that are suspended in the air. The particles consist of carbon dioxide and carbon monoxide. Formation of smoke happens when a lit cigarette is puffed or when it smoulders when not being puffed (Centers for Disease Control and Prevention 2010). The butt end releases mainstream smoke during the puffing process while the sidestream smoke is released from the burning cigarette coal in the process of smouldering. At the same time, the air within the immediate vicinity of an active smoker has a combination of exhaled mainstream smoke and sidestream smoke (Ohlemiller 1995). Conclusion The prevalence of smoking and its proclivity for causing fires under complex circumstances has made it a potential cause of fatal fires and injuries in situations and places where it is inappropriate. Since most homes are filled with substrate materials that will burn once ignited such as clothing, upholstered furniture and mattresses, they are vulnerable to carelessly discarded cigarettes. However, despite the fact that discarded cigarettes have been widely reported to be a cause of fatal fires, they can cause fires only under certain conditions and circumstances. As a result, cigarettes may not cause fires when conditions that support smoldering are not available. References Anon 2013, Officials: Fire that destroyed Abilene home caused by discarded cigarette, KTXS.com, viewed 9 Feb 2013, http://www.ktxs.com/news/fire-destroys-a-home-on-pioneer-drive-in-abilene/-/14769632/23039438/-/rq4x2x/-/index.html Baker, R 2006, "Smoke generation inside a burning cigarette: Modifying combustion to develop cigarettes that may be less hazardous to health," Progress in Energy and Combustion Science, Vol. 32, 373–385 Krasny, J 1987, Cigarette Ignition of Soft Furnishings - a Literature Review With Commentary, Center for Fire Research National Bureau of Standards, viewed 9 Feb 2014, http://www.nist.gov/el/fire_research/upload/TSG_2_Krasny.pdf Centers for Disease Control and Prevention 2010, Chemistry and Toxicology of Cigarette Smoke and Biomarkers of Exposure and Harm, viewed 9 Feb 2014, http://www.ncbi.nlm.nih.gov/books/NBK53014/ Duncan, J & Turnbull, J 2008, Discarded Cigarette Linked to Fatal Fire, viewed 9 Feb 2014, http://news.smh.com.au/national/discarded-cigarette-linked-to-fatal-fire-20080123-1nnn.html Ermala, P & Holsti n.d. 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Beiträge zur Tabakforschung International 21(5), 294-302 NFPA 2011, Home Fires That Began With Upholstered Furniture, National Fire Protection Association, viewed 10 Feb 2014, http://www.nfpa.org/research/reports-and-statistics/fire-causes/household-products/upholstered-furniture Ohlemiller, T, Villam K, Braun, E, Eberhardtm K, Harrism R, Randall, L & Gann, R 1995, “Quantifying the Ignition Propensity of Cigarettest," Fire And Materials, Vol.19,155-169(1995) Pattinson, R 2014, Builder died from carelessly discarded cigarette, inquest hears, Liverpool Echo, viewed 9 Feb 2014, http://www.liverpoolecho.co.uk/news/liverpool-news/builder-died-upton-carelessly-discarded-6645719 Tawadrous, M 2000, Fire Investigation Cigarettes: How Often They Cause Fires?viewed 9 Feb 2014, http://www.tcforensic.com.au/docs/uts/essay5.pdf Trett, J 2002, Discarded Cigarettes Causing Problems, Keizer Fire District, viewed 9 Feb 2013, http://www.keizerfire.com/News.asp?NewsID=16 Read More