Refineries produce Liquefied Petroleum Gas (LPG) and store the LPG in cylindrical or spherical tanks. If the LPG tanks are exposed to a fire of sufficient duration and intensity, they can undergo a Boiling Liquid Expanding Vapour Explosion (BLEVE). A BLEVE is an extremely powerful explosion. BLEVE gives rise to the following effects: (1) blast wave, (2) fireball, and (3) fragments. The world has witnessed many BLEVE incidents. This study aims to evaluate the BLEVE fireball thermal radiation threatening the safety of workers and communities, focusing on the 1000 m3 LPG spherical tank as a case study. The Areal Locations of Hazardous Atmospheres (ALOHA) program is employed to evaluate the thermal radiation. The BLEVE fireball thermal radiation impacts have been estimated at 10%, 20%, 30%, 40% and 50% of the capacity of LPG – 6. The farthest thermal radiation threat zones are identified in case of half full tank as follows: (i) the potentially lethal red zone extends up to almost one km, the workers and the neighboring community who are outside their offices and shelters will be at risk (ii) the second-degree burns, the orange zone extends up to one and half km, and (iii) the pain yellow zone extends up to two kms.