The Grounds of Cigarette Propensity and Potential to Cause Fires - Term Paper Example

Name : xxxxxx Tutor : xxxxxxx Title : Cigarette fires Institution : xxxxxxx @2016 Abstract This paper gives an in-depth discussion and analysis on cigarettes use as possessing the potential to cause fire hazards. It also gives some of the ways in which such fires are ignited or caused by cigarettes included all the dynamics affecting its spread. The paper also gives some of the safety features and standards that have been put in place to check on the cigarette related fires. The various experiments by various scholars on the grounds of cigarettes propensity and potential to cause fires are discussed in detail herein. Introduction Cigarette is basically a mound of dried and refined tobacco leaves rolled neatly in a cylindrical thin sheets of paper and are consumed by igniting its tip and inhaling the smoke from the other tip. In some other cases, cigarette holders may be used as well as incorporation of other technologies such as filters that are used to check on the purity of the smoke inhaled by the users. Rates of cigarette smoking have been known to vary greatly throughout the whole world since its initial use in USA way back in the year 1860. Cigarette use have been known to decrease or rather level of in the developed world while adopting a rapid increase in the developing or third world1. Cigarette smoking is a habitual endeavor that has been associated with other serious risks apart from health related risks. Careless smoking have been known to cause over 50% of domestic fires in the entire world. This is specifically attributed to the careless dropping of cigarette butts in places that may lead to ignition and finally fires. Ignorance of smokers on the need to take smoking as a serious fire hazard as well as their sole responsibility of installing smoke detectors in their homes of residence and ensuring that they are in perfect working conditions always is the sole reasons as to the high percentage risk of cigarette fires. Fire safety departments in every country have also tried to curb this menace by enforcing some fire safety policies for cigarette related fires. Such includes some basic precautions that smokers who do not find it fit to quit smoking to follow while or after smoking. These includes signposting of the danger of smoking on the grounds of causing fires. The fire safety department also centralizes smoking areas so as to monitor risks of fire apart from controlling pollution of environment. Such measures are done by designating smoking zones in various places to avoid risk of smokers smoking uphazardly and disposing cigarette butts in places prone to ignition3. Cigarette sticks fire causing dynamics Each cigarette stick manufactured are designed to contain approximately 0.8g to 1g of dried tobacco leaves. The leaves are typically hand rolled or machined rolled in thin sheet of paper. Such a cigarette have been determined to have a potential of outputting 5W of heat on ignition. The cigarette while burning attains temperatures that goes as high as 750ºC - 900ºC. Cigarette sticks enclosed within an insulating material is known to burn slowly although hand rolled cigarettes as well as cigarette pipes are associated with the capabilities of self-igniting. As a result of the need to put a check on the safety of the surrounding from the high potential of cigarettes to cause fires, a safety requirements for all cigarette manufactures was enforced. This came as a policy or a standard requirements needed for the cigarettes to be accepted in the global markets2. The cigarettes fire safety requirement The cigarettes` fire safety requirements stipulated that the manufactures should design cigarettes sticks with capabilities of extinguishing themselves if lets unattended for some time. This ensured that the cigarette butts that may be dropped careless by ignorant smokers would extinguish themselves and prevent a potential fire hazard1. In November, 2011, all cigarettes manufactured and sold in the European Union global markets were required to have a Reduced Ignition Propensity (RIP) or Low Ignition Propensity (LIP). However, since meeting such a demand is a difficult endeavor, the policy required that approximately 20% of the cigarettes in a designated batch should have the self-extinguishing capabilities4. The ISO standard ISO 12863:2010 stipulates a requirement that only 25% of RIP cigarette batch are permitted to burn to full length without self-extinguishing. Eventually, the ASTM standard E2187-02b was adopted as a standard method for measuring the strength of ignition of cigarettes and was effective from 29th June 2004. Cigarettes ignition propensity The ignition of cigarettes is attributed to the natural air convection as well as the heat transfer around the cigarettes that normally results in smoldering. Smoldering and ignition of cigarettes normally depends on presence of cellulosic materials as well as PU foams in the vicinity7. Cellulose smoldering The tobacco molds as well as the paper covering it al both cellulose based and as such smolder transfer from the cellulose within the cigarette to other near cellulose based or fabric based materials is eminent e.g. cotton and PU foam. However, some of the materials like thermostatic fabrics, wool fabrics as well as halogen based materials has smolder resistance and tend to interfere with rapid transfer of smolder5. The diagram below summarizes the smoldering behavior of cigarettes when subjected to various smoldering conditions. Figure 1: Cigarette smoldering characteristics in various conditions (Hall 2006) Foam smoldering A limited amount of PU foams are found to smolder when in contact with smoldering cigarettes unless under presence of fabric cover. Under such conditions, only 5% of combustion products consisted of carbon monoxide. The smoldering process however can be categorized into two phases as before where the first phase resulted in non-smoldering tar while the final phase resulted in smoldering char formation8. Figure 2: Cigarette smoldering characteristics in foam (Hall 2006) Factors affecting cigarette ignition propensity The following factors have been found by many authors and researchers to have a direct effect on the cigarette ignition propensity. Length of cigarette – the length of the cigarette has a direct effect on the time the cigarette will burn and thus increases the chances of it being dropped and subsequently causing ignition. Burning rate – This is determined as a measure of change in length of cigarette with time. The cigarette either burning naturally or being smoked has an effect on the burn rate and may affect the length and subsequently its probability of being dropped and causing ignition9. The table below summarizes the effect of substrate and additive on the burn rate of the cigarette. Figure 3: Effect of tobacco additive and substrate on burn rate (Krasny 1987) Thickness of the cigarette – the diameter of the cigarette has a direct effect on the burning rate of the cigarette. The larger the diameter, the slower the burning rate and the contrary is also true. Moreover, the decrease in the cigarette diameter results in a subsequent reduction in the contact area between the cigarette and the substrate and thus reduction of available fuel. The packing density – Lower packing density means that there is a reduction in the available fuel and thus reduction in the smoldering effect. Type of tobacco – the various types of tobacco in use have varying yield as well as burn rate due to variations in its constituents. This therefore affects the cigarette ignition propensity. Paper dimensions – The parameters of the paper affect the heat yield , the paper parameters also has a direct effect on the permeability of oxygen flow from outside air to the combustion zone of the cigarette and this affects the ignition propensity of the cigarette. Cigarette burning characteristics Several scholars and researches have done various works on the variation of temperatures of cigarettes both in air and when puffed. When puffed, cigarettes attain a maximum burning temperature of up to 850º. Cigarettes when puffed have been found to have an average burning rate of approximately 5mm/min according to experiments by various scholars and researchers7. However, the burn rates as well as maximum attainable burn temperatures attainable are highly depended on the substrate availability on the cigarette. The burning characteristic of cigarettes should also be noted that it highly depends on the type of cigarette either RIP or LIP. Temperature distribution in a free burning cigarette There are limited differences between the solid as well as the gaseous phase temperatures at any location within the cigarette. The figure below summarizes the pictorial representation of the distribution of temperature from both solid as well as gaseous perspective for a free burning cigarette10. Figure 4: Temperature distribution in a solid in free burning cigarette (United States 1984) Figure 5: Temperature distribution in the gases within the free burning cigarette (Krasny 1987) Modes of cigarette ignition in domestic fires The various fires on a domestic setting caused by careless disposal of cigarette remaining can be started in one of the following ways. a) Smoldering of mattresses The PU foam that makes up the mass of the mattress gets upholstered through smoldering as in furniture. Mattresses made of polythene foam are also susceptible to smoldering, however, later rubber have been found to smolder at a relatively higher rate than the other mattress materials4. The rate of smoldering also depends on the nature of bed as well as the arrangements of the beddings within the bed. Traditional box spring mattresses have been found to easily smolder as compared to the several other types of mattresses. Figure 6: Smoldering of a mattress by cigarette ignition b) Smoldering of bed clothes Smoking while in bed makes the bedroom susceptible to a fire hazard. This is due to the fact that bedclothes have a high capability of smoldering. Blankets as well as some polyester duvets have been found through experiments to smolder when subjected to cigarette fires. They are known to ignite easily with a naked flame and are mostly consumed by vigorous flames. The same principle applies to both cotton as well as polypropylene blankets that are associated with easy to burn characteristics8. Woolen blankets are the only ones that are found to have a high resistance to smoldering by cigarettes. In cases where the fire resistant mattresses are covered with mattresses or duvets, they smolder and get ignited easily. Figure 7: Smoldering of bed clothes c) Smoldering of furniture Furniture mostly made of mattresses, fabric texture or weaving are known to upholster or catch up fire by cigarettes through smoldering. Orientation and geometry of the furniture affects the rate of smoldering and determines the probability of catching fires. Burning cigarettes when trapped between the joints of the back rest and leg rest of a chair or any other furniture would lead to easier smoldering of the furniture. The picture below shows a typical smoldering of furniture by cigarette7. Figure 8: An upholstered furniture Conclusion Smoldering of cigarette buts is a common phenomenon that causes most domestic fires and can be minimized is smokers take the safety precaution as their responsibility, Several safety measures have been put in place to minimize the fires as a result of cigarettes and among these is the cigarette safety standard that should be adhered to by all cigarette manufactures,. Fire hazard as a result of cigarettes should be taken seriously just like any other hazard. Bibliography 1. RAY, D. R. (1993). Societal costs of cigarette fires. Washington, DC, U.S. Consumer Product Safety Commission. 2. HARWOOD, B. (1993). Cigarette fire incident study. Washington, DC, The Commission. 3. HALL, J. R. (2006). Behavioral mitigation of smoking fires through strategies based on statistical analysis final project report for EME-2003-CA-0310. [Emmitsburg, Md.], Dept. of Homeland Security, U.S. Fire Administration. http://purl.access.gpo.gov/GPO/LPS106249. 4. U.S. CONSUMER PRODUCT SAFETY COMMISSION, & KRASNY, J. F. (1987).Technical Study Group Cigarette Safety Act of 1984. Washington, D.C., Technical Study Group on Cigarette and Little Cigar Fire Safety, Consumer Product Safety Commission. 5. MITLER, H. E., & WALTON, G. N. (1993). Modeling the ignition of soft furnishings by a cigarette. Gaithersburg, MD, U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology. 6. GANN, R. G. (1988). The Effect of cigarette characteristics on the ignition of soft furnishings. Gaithersburg, MD, U.S. Dept. of Commerce, National Bureau of Standards. 7. U.S. CONSUMER PRODUCT SAFETY COMMISSION. (1987). Toward a less fire-prone cigarette final report of the Technical Study Group on Cigarette and Little Cigar Fire Safety. Washington, D.C. (5401 Westbard Ave., Washington 20207), Copies from C.B. Church, Secretariat, Technical Study Group, Consumer Product Safety Commission. 8. MARKOWITZ, S. (2010). Where there's smoking, there's fire the effects of smoking policies on the incidence of fires in the United States. Cambridge, Mass, National Bureau of Economic Research. http://papers.nber.org/papers/w16625. 9. UNITED STATES. (1984). Cigarette Safety Study Act: hearing before the Committee on Governmental Affairs, United States Senate, Ninety-eighth Congress, second session, on S. 1935 to establish an Interagency Task Force on Cigarette Safety, May 10, 1984. Washington, U.S. G.P.O. 10. KRASNY, J. (1987). Cigarette ignition of soft furnishings: a literature review with commentary. Washington, D.C. (5401 Westbard Ave., Washington 20207), Copies from C.B. Church, Secretariat, Technical Study Group, Consumer Product Safety Commission. Read More