Safety standard delay decision a cautious welcome

02 September 2009

Laidler Associates welcomes the news that the replacement of the well-known EN 954-1 safety standard is likely to be delayed. Nevertheless, the company emphasises that this move does nothing to change the fact that EN 954-1 is deficient in many areas. Expert guidance is, therefore, highly desirable when relying on this standard, particular in relation to new designs.

A new standard, EN (ISO) 13849-1 "Safety of machinery, Safety-related parts of control systems", had been expected to replace EN 954-1 this year. However, machine and control system builders expressed serious concerns about difficulties in applying the new standard in practice, particularly as it calls for component MTBF (mean time between failure) data that, in many cases, is not currently available.

In response to these concerns, the Machinery Directive Working Group of the European Environmental & Technical Regulation Directorate announced that it was receptive to the idea that EN 954-1 could continue to be accepted "for a certain time", while it is still referenced by harmonised standards. It has been suggested that the extended period of acceptance is likely to be either three or five years.

"For most control system and machine builders, this is very good news," said Paul Laidler, managing director of Laidler Associates, "since it gives time for the work needed to underpin the new EN 13849-1 standard to be carried out carefully and thoroughly. Nevertheless, retaining EN 954-1 does have its downside, as there are many areas that this standard doesn’t cover including, for example, programmable safety equipment, which simply didn’t exist when it was formulated."
"For this reason, control system and machine builders must be careful about placing too much reliance on EN 954-1 as a way of demonstrating that they have fully met their obligations in relation to control system safety. This is, in fact, a complex area where most companies will benefit from expert guidance."

"At Laidler, we have used our wide experience in industrial safety and compliance to carefully analyse this complex situation and the issues it creates. As a result, we are in a prime position to provide that guidance."

Laidler’s focus in providing consultancy services for EN 954-1 and EN 18439-1 is to work with its clients to develop comprehensive and dependable solutions that are practical, convenient and cost effective.