Two sub-contracting carriers from a rendering plant were transferring a 96% sulphuric acid solution from an intermediate bulk container (IBC) to their customer’s tank. At around 10 a.m., acid sprayed into the faces of the two drivers when they attempted to disconnect the tank-side acid transfer hose.

As the safety shower was out of service, the two operators sprayed each other down with a water hose before being taken to the hospital.

One of the subcontractors, still in training, did not follow the transfer procedure. He had closed the customer-side valve before the pump was switched off, thereby leaving the transfer hose under pressure and filled with acid. As a result, acid sprayed out when the hose was disconnected. The second, more experienced driver, had not adequately fulfilled his role as the trainer.

Moreover, contrary to the prescribed procedure, a rendering plant employee was not present during the transfer operation. Also, the safety shower had not been tested before initiating the transfer operation. Finally, the transfer zone is somewhat cramped and not very ergonomic (the customer-side valve is located in a cabinet).

The carrier reminded its employees and subcontractors of the loading procedures:

• emergency devices, such as the safety shower, must be checked prior to beginning operations;
• the importance of respecting the chronology of the valve operating procedures;
• the importance of wearing PPE.