Machinery Directive 2006/42/EC & EN ISO 13849-1; 2006 – with comments

By J.B. Titus December 10, 2009
The EC Machinery Working Group met on Dec. 8, 2009 and voted to prolong the cessation of EN 954-1; 1996 beyond Dec. 31, 2009 and, therefore, to provide presumption of conformity to the new Machinery Directive 2006/42/EC which also becomes effective at the end of this month. The story continues this time because the European Commission (EC) has not stated how long this prolongation will be. So, we ask the question, who in the United States cares?

There are already a lot of opinions on this question so here’s one more!

First, I divide the US machine industry into three segments; OEM, supplier, and end user. And, each of these segments can have locations or customers domestically, internationally, or both. In my opinion it’s critical to understand this landscape in conjunction to understanding domestic versus international safety requirements as well as safety requirements that can be imposed contractually.

Secondly, and historically, there’s been a strong reluctance here in the US for standards bodies to normatively (versus informatively) require compliance to European standards. Recent harmonization efforts in the US have shown a tendency to adopt individual lines of code or the “intent” but not the entire standard. Several safety standards have informatively referenced EN 954-1 and it’s apparent replacement EN ISO 13849-1 but seldom if ever have they been normatively required by the standards bodies. Contractually is a different story because several purchase orders from various companies have required compliance typically because the end user companies have multiple plants located around the world.

Thirdly, to answer the question, in my opinion all three US segments are not likely to be impacted by regulatory compliance requirements domestically caused by this EC decision. However, all three US segments can definitely be impacted for compliance to the Machinery Directive, EN 954-1, and EN ISO 13849-1 based on either regulatory and/or contractual opportunities resulting from applications in Europe. Alas – in the weeks to come you’re guaranteed to hear lots more about last Tuesday’s EC decision which postpones the presumption of conformity via EN ISO 13849-1.

This is one opinion among many so if you have a different opinion or a supporting opinion we’d like to hear from you……..?

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Posted by J.B. Titus on December 10, 2009


January 16, 2010

In response to: Machinery Directive 2006/42/EC & EN ISO 13849-1; 2006Lundin commented:

As an European engineer struggling with these standards, I think it would be great if the US -don’t- recognize them or enforce them nationally, but rather dismiss them.

Just the fact that there are two nearly identical, overlapping standards is laughable. The reason behind this is ridiculous prestige between English bureaucrats and German bureaucrats.

In addition to that, both ISO 13849-1 and EN 62061 are essentially bureaucratic nonsense, with little or no connection to real world engineering, and with little or no scientific proof that the various activities enforced actually lead to safer systems.

I’m actually quite sure that all these fluff standards don’t lead to increased safety in their own. I’ve dissected several “SIL 3″ systems that have gone through notified body approval from famous test houses, and then with a single short circuit in a relay I can make them lose the safety function entirely. SIL 3, my old shoes.

Sure, there is a nice spin-off effect from producing the piles of paper required: you will ultimately end up going through your design once more, and perhaps find some flaws in it. But the detection of such flaws typically comes from common sense and engineering skill, rather than the fuzzy methods enforced by the nonsense standards.

For example, the demands on software in ISO 13849-1 are on a very rudimentary level, incredible vauge and likely useless on complex high-level software. They have no connection to scientific research in the area of safety-critical systems.

The fanatic focus on MTTF (minimum time to failure) in the standard is another oddity. This is a remain from ancient dinosaur days, where people calculated how much time they had left before the inevitable disaster, instead of actually preventing the disaster from occuring. Modern system design doesn’t care at what point in time a failure happens, but focuses on what measures there are for detecting the failure and preventing it from leading to hazardous situations.

I think the US can learn from this European fiasco and take an entirely different approach in future legislation regarding safety-critical systems.

December 29, 2009

In response to: Machinery Directive 2006/42/EC & EN ISO 13849-1; 2006Clive Lee commented:

With the working life extention of EN 954-1, it should be noted that EN ISO 13849-2 is the validating standard that ensure compliance. So what is the difference?

EN ISO 13849-1 gives the tool for quantifying the reliability needed to ensure safety in the terms of performance levels. With out EN ISO 13849-1 can it be assumed that reliability has to be defined using EN 62061?

December 12, 2009

In response to: Machinery Directive 2006/42/EC & EN ISO 13849-1; 2006Bill commented:

Working compliance for an OEM exporting to the EU, this is big. With today’s lean staffing and the technical chalenges presented with EN62061, we have been slow to replace EN954. It can legally put it off a little longer now.