DougN 
😷 
A few years ago I collaborated with some other researchers on a paper you might be interested in reading:
Safety of Machinery: Significant Differences in Two Widely Used International Standards for the Design
of Safety-Related Control Systems
It's available to download for free from the publisher.
https://link.growkudos.com/1qcrx02w7i8
#MachinerySafety #WorldStandardsDay
Differences between ISO 13849-1 and IEC 62021 for industrial machinery control systems
Two main standards are commonly used to design safety-related control systems for industrial machinery: ISO 13849 and IEC 62061. ISO 13849 has a long history, stretching back to EN 954-1:1996, while IEC 62061 is derived from IEC 61508 and was first published in 2005. An informal survey done in 2012 showed that about 95% of machine builders use ISO 13849 rather than IEC 62061 or any other standard. While the two standards are focused on the same topic, they take significantly different paths and produce similar but different classifications for the reliability of safety-related control systems. This paper looks at the differences and pros and cons of each approach.