Functional Safety From UL - Let's Discuss!

Certainly, functional safety evaluations can play a large role in improving levels of machine safety in industry. However, let's start discussing the transitional issues. Old practice of determining hazards under EN 954-1 qualitatively is being replaced by ISO 13849-1 and the new quantitative PL approach.


J.B. Titus, machine safety bloggerCertainly, functional safety evaluations can play a large role in improving levels of machine safety in industry. By providing more consistency between SIL (Safety Integrity Level) and PL (Performance Level) via both being probabilistically derived should help. The old practice of determining hazards under EN 954-1 qualitatively is being replaced by ISO 13849-1 and the new quantitative PL approach. Additionally, the new approach addresses the use of programmable electronic safety devices and technology in the safety-related control system. UL, Underwriter Laboratories, says it is the standard in safety.Yet, the old way of providing machine safety via hard wired electromechanical components is still considered an approved approach for machine safety. This presents a rather broad range of considerations for industry regarding their mandated OSHA conformance to providing a safe work place. This is why in my previous blog on this subject posted Dec. 17, 2010 I stated, “In my opinion, we need to start a discussion on this subject to gather comments from across industry.”




To address this issue I’ve started a discussion at a Safety Forum on Linkedin. I urge you to take some time to post your comments, questions, advice, etc. on this issue so that we can improve our collective understanding of this transition. For example, I find a lot of great information on the UL Functional Safety web site but one of my take away’s is that a lot of the material appears to be focused at the manufacturer or OEM. What would your opinion be? If you agree, how does the end user comply with the same industry standards when they install a field retrofit on a used machine? The end user may not have the technical staff to perform the required engineering and analysis. In the US, industry standards apply to the manufacturer, OEM, Systems Integrator and the end user. In fact, OSHA points the ultimate responsibility and enforcement to the end user.


Are these issues too complicated or does it only appear that they might be complicated and in reality they’ll work themselves out?




Submit your ideas, experiences, and challenges on this subject in the comments section below. Click on the following text if you don't see a comments box, then scroll down: Functional Safety From UL - Let's Discuss!






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Functional Safety – A New “Mark” From UL


How To Integrate Safety


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