At around 8 p.m., in a factory specialising in the manufacture of ultra-pure chemical compounds, a forklift operator accidentally punctured a container of 50% hydrofluoric acid (HF) stored in the site’s warehouse. The acid (extremely corrosive) flowed through the gap made in the plastic wall of the container. A puddle spread across the floor of the warehouse, creating a thick cloud of toxic and corrosive white vapours. The operator evacuated the premises and raised the alarm.

The fourteen members of the in-house emergency services team equipped themselves with integral protection suits and gas masks. They installed absorbent booms and covered the puddle with absorbent materials to limit the formation of vapours, which stopped 45 minutes later. Within four hours the premises had been rinsed, although the vapour cloud did not dissipate. The 3.5 m³ of HF contained in the containment area and the 45 m³ of water used to rinse the storage area were pumped and disposed of off site. The solid waste was disposed of by an approved service provider. This waste consisted of 1 t of contaminated PPE (personal protective equipment), 1.1 t of contaminated wooden pallets, 200 kg of electrical equipment (computers, telephones, etc.) and two electric forklifts destroyed by vapours, 3.2 t of corroded steel partitions and 1 t of lime sludge used to neutralise the acid. Operating losses were estimated at €8000 and damages at €240,000.

The HF storage tank feeding a production tank was unavailable. This required the operator to have 50 t of HF delivered in containers. This unusual volume of HF containers overloaded the warehouse’s storage racks. The 1-tonne containers were stored on two levels over their entire width (1 m) and touching one another. On the day of the accident, the forklift driver attempted to realign a container that was placed on top of another container. He was unable to clearly see the forks of his forklift due to the density of the storage configuration. The container slid towards the back. The forklift’s forks (1.2 m long) extend the full width of the container which slid and hit the container stored just behind it. These plastic containers are single-walled since the supplier was out of stock of the double-walled variety. The risk of a container slipping and the risk of it being punctured by the forklift forks were not taken into consideration in the hazard study. Only tipping over during transport was considered. The containers were handled and stored in the widthwise direction (1 m). If this had been made in the direction of the container’s length (1.2 m, i.e. the length of the forklift’s forks), the puncture would not have occurred.

The operator implemented protective devices on the forklifts’ forks (anti-puncture and anti-slip). The storage direction of the containers was modified in the lengthwise direction and the storage of containers with a length less than 1.2 m was avoided. The supplier was asked to deliver only double-wall type HF containers.