An explosion and ammonia leak (NH3) occurred 30 minutes following start-up of a brewery refrigeration unit. An employee sustained eye burns. A second explosion with flames then occurred. A liquid NH3 tank (475 litres, 12 bar), at the condenser output, was connected to an overheating cylinder by a pipe fitted with a lens and a manually-adjusted valve to pulverise the NH3 into droplets and lower pressure to that of the cylinder. The leak occurred on this recycled, modified tank adapted to the unit, which displayed penetration-free welds. The NH3 that filled the premises ignited with a spark from the electrical cabinet (destroyed by the explosion), or on the bare light bulbs used to illuminate the room, or the glass level (broken by the cold NH3 vapours); the tank then exploded from the heat. A 2-m2 hole was ripped through a 25-cm wall, a staircase was moved 10 cm, and the tank bottom was projected a full 15 m. The site was closed the following year.