Research Journal of Recent Sciences _________________________________________________ ISSN 2277-2502 Vol. 3(10), 59-62, October (2014) Res.J.Recent Sci. International Science Congress Association 59 Fire Safety Assessment on Seven Flooring MaterialsRoman MichaloviFaculty of Special Engineering, Mikomix, Druinská 897, Rosina, SLOVAKIA Available online at: www.isca.in , www.isca.me Received 25th November 2013, revised 22nd March 2014, accepted 17th May 2014Abstract Seven flooring material were tested in order to find out their properties from fire safety point of view. Following three indexes were measured: mass loss, flame spread rate and emissions of CO, NO, SO, O were monitored. The fire safety characteristics of synthetic materials are mostly negative due to faster mass loss comparing to the natural materials. Based on the results one of the materials is no more recommended for the use due to health and safety risk character. Fast mass loss in hand with its toxic emissions of phthalates and dioxin make PVC a very risky flooring material. We do not recommend its use. Nylon (polyamide) carpets should be not used due to their high flammability. Wooden based floorings such an oak parquet, spruce board, OSB boards are high recommended. Linoleum and Laminate floorings, especially due to low flammability are recommended, too. Keywords: Fire safety, flooring, burning, mass loss, flame spread rate, emissions. Introduction Variety of flooring materials is used at the time. Natural materials as wood and wood imitations combining natural and synthetic materials have becoming popular in constructing and interiors. There are widely common laminate and PVC floorings. Carpets from natural or synthetic fibers represent another group. The base is usually made of non-flammable materials such as concrete or stone tiles. In case of fire the behavior of mentioned materials varies. It depends on the physical and chemical properties of each type. There are different initiating combustion temperature, rate of flame spread, mass loss and chemical composition of emissions that are released during combustion. In terms of STN EN 13501-11 flooring materials represent all classes of flammability from non-flammable Class A (concrete, granite, etc.) to flammable Class F. The wood-based floorings belong to class C, D, E (moderate flammability). Polyamide or nylon carpets belong to the class F, group of easily flammable materials. The aim of laboratory measurements was to determine the behavior of the various types of flooring standard thickness at building fires. The main indicators clearly show the mass loss, the rate of flame propagation and release of emissions into the air. The samples of beech wood flooring, OSB boards, spruce flooring (decking), linoleum, laminate flooring, PVC and synthetic carpets .were tested. Mass loss of OSB was studied by Galla. Thermal quantities of various wood spices including fire retardants were deeply studied by Martinka, Kaíková, or Osvald. Emissions measurement is a fundamental part of thermo-chemical works. The variability of emission results when combusting or burning the same wood spices was proofed by numerous studies by Müllerová5-7, Valíek. Health risk and environmental risk should be always considered when dealing with harmful emissionsCombustion of natural material is not alwaysecological and harmless as was proofed by Beníková10 and Müllerová11 in their wood combustion studies. Especially high CO is problematic. Characteristics of tested materials: Beech parquet belongs to flammability class Cfl12 (table-1), flame retardant with limited development of smoke s1. A typical thickness is 21mm, humidity 9% ± 2%. They are sought after the long life (minimum 75 years), heat and sound insulation properties. Parquet floors without surface treatment were used for laboratory tests. Spruce courtside is milled from a dry timber with a moisture content of 10% ± 2 %. Each board has a tongue on one side and on the other side of the groove. Individual pieces fit together and form a perfect connection, without spaces, without the use of adhesives. Thickness is 22mm. It is mainly used in holiday cottages and private houses. OSB boards (OSB - Oriented Strand Board) is made from large particles of wood pressed flat chips, which are pressed under the influence of high pressure and temperature, with the use of synthetic resins based on formaldehyde. Formaldehyde at higher concentrations causes nausea, headaches. At concentrations of 120 g/m is fatal13. Linoleum is a material made from jute fabric that forms the backbone of the flooring substrate, linseed oil and cork, wood or limestone flour, natural resins and color pigments. The advantages include linoleum elasticity, good thermal insulation at the current suitability for use with under-floor heating, static character, tough inflammability, resistance to temperature Research Journal of Recent Sciences ______________________________________________________________ ISSN 2277-2502Vol. 3(10), 59-62, October (2014) Res. J. Recent Sci. International Science Congress Association 60 changes, cigarette butts, oil and grease, and partly acids and solvents. Linoleum is bacteria-static material. Laminate floating floor is rough only six to eight millimeters, its core is in the form of densified wood or pressed wood fibers. Decorative foil or paper is pressed onto a layer of melamine resin, and protective coating is applied. Stability is ensured by the bottom layer. Among the harmful chemicals that are found in floating floors include phenol and formaldehyde. Phenol and formaldehyde is a part of adhesives used to join the individual layers together13. PVC floorings are produced either with a single-layer or multi-layer decoration and transparent top layer. Their danger lies in the chemical composition and emissions that are released during combustion. The smoke released by its burning is toxic, containing phthalate, chlorinated paraffin, and sometimes lead or tin compounds. When incomplete combustion of propane and chlorinated hydrocarbons occurs, after the contact with hot metal they can be converted to phosgene. The properties of PVC compounds are described by European14 and American15institutions and well known authors16,17. Polyamide carpets are dominant due to the competitive prices in the market. Fire resistance polyamide is very low comparing to carpets made of natural fibers. The basic material of synthetic carpet fibers is nylon (polyamide, nylon) which is extracted from the oil. At temperatures from 40°C to 100°C does not change the properties at temperatures above 150°C starts to degrade. Nylon carpets are characterized by high strength, elasticity, resistance to moisture, abrasion with a relatively low weight. The main disadvantage of carpet is accumulation of dust and dirt. Carpets can accumulate filth and dust 8 times higher than its own weight. We tested a polyamide carpet, which was tufted into a synthetic jute grid, so-called AB base. When incomplete combustion dangerous carbon monoxide (CO), very toxic hydrogen cyanide (HCN), hydrogen chloride (HCl), carboxylic acid, ether and ammonia are released14. Methodology Laboratory measurements were conducted at room temperature of 23°C ± 2°C and a relative humidity of 50% ± 20%. The chamber was formed party firmly embedded plates. The floor of the test chamber is made with ceramic tiles of approximately 1m. Front of the chamber formed by transparent glass panel. The ceiling of the chamber is made of metal and glass and one exhaust chimney fan. The end edge of the burner is at a distance of 25mm horizontally and 30mm vertically from the surface of the floor covering. The longitudinal axis of the burner corresponds to the longitudinal axis of the sample. The size of the burner flame is adjusted on the gas bomb. Fuel source is propane, which we shall be discharged under pressure of 0.5 bar (50kPa). Flame spread rate was measured by a stopwatch to the nearest tenth of a second, the weight of the samples was determined with a precise digital weighing 0.1 grams. For each type of material 10 samples were tested. Values expressed in graph and tables are the arithmetic average of the measured values. Each sample was weighed before the experiment and after extinguishing the samples at the end of the experiment. Results and Discussion Tests flooring wood-based materials were milder than synthetic materials tests. PVC and polyamide carpet completely burnt through while in materials containing wood it didn’t happened. Percentages of mass loss measured after 10 min permanent flame exposure are on graph at figure-1. The lowest mass loss was recorded in natural flooring materials - wood-based floorboards from spruce (4.85 %), OSB (5.34 %) and beech parquet (8.69 %), the mass loss was less than 10%. Highest mass loss was measured with a polyamide carpet (21.96%). The second highest average value was recorded for PVC (17.33 %). Figure-1 Average mass loss values of tested flooring materialsTimes measured at 10cm intervals confirmed the anticipated slowing down of the flame spread. This is reflected in the decreasing mass loss. Laboratory measurements at Technical University Zvolen confirmed that samples with increasing distance from the source of heat radiation decreases the total mass loss.18 Linear trend of mass loss was proofed for majority of the samples. The similar results were obtained in the National Institute for Fire Technology and Expertise19. Measurements focused on emissions released by burning beech wood and laminate floating floors have been made by Uysal.20according the American standard ASTM E – 6. Duration of measurement was consistent with our measurements, i.e. 10 min. Experiments conducted in the Testo 300 M, the measurement of the emission was recorded by XL flue gas analyzer. Samples of beech wood and laminate flooring contain the emissions of standard gas monitoring (table-2)20. The values in table-1 recorded distance of flame spread rate for different flooring types after the first minute of the experiment. Continuously, the spread rate had been slowing down. Table-2 0%5%10%15%20%25% Research Journal of Recent Sciences ______________________________________________________________ ISSN 2277-2502Vol. 3(10), 59-62, October (2014) Res. J. Recent Sci. International Science Congress Association 61 show that emissions from laminate flooring especially in the case of NOx are almost three times higher than for the same size sample of beech wood. Mass loss values correspond to our measurements, which also recorded doubled value of mass loss laminate floating floor as beech parquet. Thermo-mechanical properties as conductivity can be read out from the results referring to flame spread rate.20 Carpetand PVC have visibly higher conductivity comparing to wooden material floorings. This topic is well described in study materials by Kriššák21 and Müllerová22 or Kumar23. Table-1 Flammability classification of materials due to flame spread rate Flooring material Flame spread rate [mm. min-1] Class of fire reaction according STN EN 13501-1:2010 Board floor 118 D fl – moderately combustible OSB board 127 E fl – moderately combustible Beech parquet 102 C fl – combustible with difficulty Linoleum 122 D fl – moderately combustible Laminate flooring 137 E fl – moderately combustible PVC 175 E fl – moderately combustible Polyamid Carpet 235 F fl – easily combustible Table-2 Average emission values and mass loss of laminate flooringEmission Laminate flooring 8 Beech timber CO (ppm) 983 726 NO x (ppm) 25.1 9.95 SO 2 (ppm) 0.57 1.52 O 2 (ppm) 17.6 18.3 Mass loss (%) 21 12.1 ConclusionCareful choice of flooring materials in buildings, offices, apartments and other properties should be done considering the fire resistance of chosen material including their typical behavior when they come in touch with some ignition source. Tests mentioned above indicates that natural wood-based materials (floors, OSB boards, floorboards) out of seven tested are more suitable for the use in sense of fire safety. Laminate floating floor had also very good resistance. Compared with beech wood but has a significantly higher CO and NOemissions. The greatest mass loss had polyamide carpet and due to law ignition temperature also represents highest fire safety risk. At the same time the burning release small amounts of formaldehyde and hydrogen cyanide. Alternative carpets are made of polyester or of polypropylene fibers (PP, olefin) but less rigid with shorter lifetime. PVC is becoming one of the worst material with negative impact on human health due to the phthalate emissions released also in standard room temperatures. Several countries, including the Czech Republic already have taken steps to reduce or eliminate the use of PVC in public buildings. Using PVC in some products is completely prohibited (e.g. toys). 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