Safety first

This year marks two significant anniversaries in the annals of process plant safety - or rather the lack of it.

It is 30 years in June since the devastating explosion at Nypro's caprolactam plant in Flixborough, and ten years ago this July there was a serious explosion and outbreak of fires following a lightning strike at Texaco's Pembroke refinery in Milford Haven.

Anyone reading the official enquiry reports on these two incidents will see immediately how much had changed in the intervening 20 years. From the appallingly slapdash approach to plant safety demonstrated at Flixborough (where a temporary by-pass pipe that failed had actually been 'designed' in chalk on the workshop floor), to the then state-of-the-art plant control system in operation at Pembroke, it is clear that the process industries had learnt a great deal from the past and put safety at the core of their operations.

But as Pembroke proved, there is always something new to learn. In that case, it was a realisation that even the most sophisticated of control systems could overburden operators when things start to go wrong. One of the HSE's recommendations in its report on that accident was that safety systems should be designed on 'an appropriate hazard and risk analysis so that the functions to be carried out and the necessary levels of integrity are systematically determined'.

Which is why, ten years on, process control companies are chasing the rapidly growing market for safety instrumented systems - a market now driven by the need to show compliance with international standards such as IEC 61508 and 61511.

Process equipment manufacturers and vendors face a similarly increased emphasis on safety, particularly over the requirements of the ATEX Directive for the use of their equipment in hazardous areas.

As Emerson's Duncan Schleiss said at the launch of his company's new SIS, 'there's no excuse not to do safety by the book anymore'.