The determining of hazardous areas created by flammable and explosive chemicals is important to obtain a safe working environment. Taking precautions and prevent explosions require detailed investigations and accurate calculations instead of superficial and personal experience. In this context, possible leakages and leaks occurring around the LPG tank and its connections in a real enterprise were evaluated and the border of possible explosive atmosphere areas was calculated by the ALOAH program according to the TS 60079-10-1 standard. Based on the secondary discharge of the LPG from the bottom of the tank, the discharge characteristics were calculated as 4.946578 and 3.926692 m 3 /s at sonic and subsonic conditions respectively, and region radii, 10.8 m. The explosive atmosphere of the LPG tank was concluded that matched well the definition of Zone 2. The risk severity score of explosive atmospheres was calculated as 12 by using the risk assessment method of matrix system with approximations, possible in a week (3P), and the effect that could cause serious injury (4P). Serious threats and devastating effects were fictionalized clearly by explosion scenarios of the LPG tank. The calculations of explosive borders for flammable chemicals are necessary to prevent explosions, fires, and toxic effects of leaked chemicals by taking measurements on time. It is also necessary to calculate explosive areas and possible sceneries for each chemical separately for accurate results and effective control.