A flash followed by a fire and explosion occurred at an LPG filling station. The building depot was divided into several zones: a carrousel for filling 13-kg propane bottles, a 35-kg bottle-filling zone, a testing zone, a palletizing platform, and a painting booth. The building was fitted with 2 fans (2,000 m³/h each), servo-controlled to the product inflow. Filling was performed via a clip that when placed to the right of the bottle tap orifice initiated a pneumatic sequence (clip connection, bottle tap opening, gas valve opening, then at the end of filling, simultaneous closure of the gas valve and bottle tap, and clip removal). At 4:55 pm on the day of the accident, a 13-kg bottle tipped over upon exiting the carrousel. The technician monitoring clip connection stopped the production line, the foreman attempted to turn the bottle upright, which produced a “flash” explosion as the bottle tap had remained open. The foreman and 2 other employees sustained burns to their face and body. Another worker activated the site’s emergency shutdown, which triggered the sirens, cut electricity supply (except for lighting), closed the spherical container valves as well as inlet valves on the carrousel and 35-kg filling station, and shut down both the air compressors and fans. Due to a loss of air, the filling clips slowly opened, causing another propane discharge. The cloud ignited, with fire spreading to the painting booth. This same phenomenon occurred on the 35-kg station, where the gas exploded. A section of the roof and depot cladding were blown off. At 5:20 pm, the fire was extinguished. According to the site operator, the clips were activated via air pressure; therefore, compressor shutdown only allowed for a slow release of the clip, with a delayed interruption of product inflow; the same was true for the gas valves and bottle taps. The discharged gas accumulated inside the workshop since any evacuation to the outside was prevented once the fans stopped running. The ignition source might have been generated by a metal shock (clip/bottle or bottle/chain structure) or else by static electricity. The measures adopted were primarily focused on installing an air tank intended to increase clip autonomy, separating the electrical supply of compressors and fans (kept on automatic shutoff), and conducting personnel drills.

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