We have automated several reactors, and one specifically involved the use of hazardous area hardware due to the use of flammable materials in the process. The project was for a leading blue chip manufacturer, and was a single stand-alone system that was dedicated for a single product. A cost effective solution was required in order to automate a process that had been manual up to that time, and so we utilised a Siemens S7 300 PLC together with a standard HMI – both located in a safe area. Connection to instruments in the hazardous area was via barrier systems, and in line with the requirements the system was kept as simple and straightforward as possible. The operators were trained on the system, and although a modestly sized project it was successful in that it became quickly accepted by the operators and integrated into the plant.