Abstract—Natural wood is used in many applications in Jordan such as furniture, partitions constructions, and cupboards. Experimental work for smoke produced by the combustion of certain wood samples was studied. Smoke generated from burning of natural wood, is considered as a major cause of death in furniture fires. The critical parameter for life safety in fires is the available time for escape, so the visual obscuration due to smoke release during fire is taken into consideration. The effect of smoke, produced by burning of wood, depends on the amount of smoke released in case of fire. The amount of smoke production, apparently, affects the time available for the occupants to escape. To achieve the protection of life of building occupants during fire growth, fire retardant painting products are tested. The tested samples of natural wood include Beech, Ash, Beech Pine, and white Beech Pine. A smoke density chamber manufactured by fire testing technology has been used to perform measurement of smoke properties. The procedure of test was carried out according to the ISO-5659. A nonflammable vertical radiant heat flux of 25 kW/m 2 is exposed to the wood samples in a horizontal orientation. The main objective of the current study is to carry out the experimental tests for samples of natural woods to evaluate the capability to escape in case of fire and the fire safety requirements. Specific optical density, transmittance, thermal conductivity, and mass loss are main measured parameters. Also, comparisons between samples with paint and with no paint are carried out between the selected samples of woods. Keywords—Optical density, specific optical density, transmittance, visibility. I. INTRODUCTION ATURAL woods are widely used in buildings in Jordan, particularly kitchens, furniture and doors. Wooden materials often play an important role in the compartment fire, especially in occupancies involved by natural wood such as residential and office occupancy. Most interior finishings of buildings in Jordan use natural wood. When woods are burnt, high quantity of smoke plumes are generated. One of the major causes for death and property loses in wooden fire accidents is generation of carbon monoxide through the thermal degradation of cellulose and partial oxidation of carbon. Smoke is the airborne solid and liquid particulates in gases evolved when a material undergoes pyrolysis or combustion [1], [2]. Abdullah N. Olimat in the Fire Safety Engineering Department, Prince Al- Hussein Bin Abdullah II Academy of Civil Protection, Al-Balqa' Applied University, Jordan (corresponding author, phone: +962772187111, e-mail: olimat2012@gmail.com). Ahmad S. Awad in the Mechanical Engineering Department, Faculty of Engineering Technology, Al-Balqa' Applied University, P. O. Box: 330116, Amman (11134), Jordan (e-mail: ahmadsawwad64@yahoo.com). Faisal M. AL-Ghathian in the Faculty of Engineering Technology, Al- Balqa' Applied University, Jordan (e-mail: faysal_g@yahoo.com). Statistics illustrate that smoke inhalation and asphyxiation, rather than burn injury, leads to a majority of the fire fatalities. To protect the life of occupants and property construction from fire burning wood accidents, fire retardant material (FRM) as a form of paint is used by several researches. Products of smoke threaten life directly, either by damaging the body by toxic gases or by reducing visibility and causing disorientation from the light scattering effects of products’ gases and particles. The large amounts of smoke generated by fire is considered as a major hazard, particularly in the early stages of fire growth, which is associated with visibility problems and exposure to toxic environments. The reduction in visibility due to smoke concentration leads to a critical situation for am occupant's life protection and fire safety provisions. It affects the heart rate and blood circulation. This situation may be hazardous in case of toxic gases and high temperature products, particularly if people are not quickly able to find the means of escape. Since measuring visibility is not possible directly, opacity quantity, stopping the passage of light rays, is measured. Theoretical models for determining the optical density in smoke using Computational Fluid Dynamics (CFD) simulations were compared with the experimental data of Haukur and Bror [3]. Several experimental works were carried out and collected to find a correlation between visibility and optical density (OD) [4]. The study found that at an OD of 5.0 m -1 , a person can only see 0.6 meters in front of him. Also, they concluded that visibility limit is at a smoke OD value of 0.08 per meter, corresponding to a 10 meter visibility minimum. Reference [5] reported the optical measurements for smoke generated from burning sheets of building materials (polymers) with a two-white laser beams (Helium Neon Laser) simultaneously for checking whether forward scattering exists or not. Helium-Neon laser is found to be an effective mean for eliminating the forward scattering effects. Both gave the same amount of attenuation and the same OD with small deviation due to the non-homogeneity of the smoke and soot deposited on the glass holes. Reference [6] measured the smoke density of wood based materials like general purpose plywood, Marine Plywood (BWP grade), Medium Density Fibre Board (MDF), Bamboo Mat Board (BMB), and Pre-laminated Particle Board (PPB) using chamber methods (ASTM D 2843-70). They found that the general purpose plywood has the lowest smoke density (40.59) and marine plywood has the highest smoke density (62.81). Reference [7] carried out a measurement in non- flaming condition on smoke produced by solid materials, Effect of Fire Retardant Painting Product on Smoke Optical Density of Burning Natural Wood Samples Abdullah N. Olimat, Ahmad S. Awad, Faisal M. AL-Ghathian N World Academy of Science, Engineering and Technology International Journal of Energy and Power Engineering Vol:11, No:9, 2017 1028 International Scholarly and Scientific Research & Innovation 11(9) 2017 scholar.waset.org/1307-6892/10008005 International Science Index, Energy and Power Engineering Vol:11, No:9, 2017 waset.org/Publication/10008005