Machine Safety
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Machine Safety: IEC, ISO, ANSI, NFPA, SEMI, ASTM, ASME, NEMA machine safety compliance

The standards march: where are they headed? Which will litigation reference? For compliance? As international standards (IEC and ISO) are increasing worldwide adoption they are cited in U.S. domestic machine safety standards from ANSI, NFPA, SEMI, ASTM, ASME, NEMA, etc. Are these standards adopting or referencing IEC or ISO requirements for compliance?

May 18, 2014


As international standards (IEC and ISO) are increasing their worldwide adoption are they also becoming required for U.S. domestic compliance? We’ve had domestic machine safety standards (ANSI, NFPA, SEMI, ASTM, ASME, NEMA, etc.) for decades. Are these standards adopting or referencing IEC or ISO requirements for compliance? Where are machine safety standards headed?

Might there be global harmony in functional safety standards for machinery? There's a working group for that. Courtesy: Control Engineering Machine Safety Blog, JB Titus and Associates

Yes, we have had machine safety standards for decades. And, all of our domestic standards have established time frames for when their committee re-convenes to update their standard.

Purpose of machine standards updates

These updates are typically to:

1. Clear up possible reported confusion

2. Incorporate application changes

3. Incorporate revised requirements driven by new technology.

There may be additional reasons for an updated edition but historically the oversight bodies for U.S. standards have been reluctant to use a normative (required) reference to an international standard. It’s been my experience, with ANSI for example, that the committee would adopt a concept for incorporation into a machine safety standard. An example was the Category approach for hazards and component safety certification published in EN 954. I don’t recall ANSI ever having a normative reference to EN 954 versus incorporating the concept of Categories using ANSI normative language. Updated ANSI standards in the late 1990s and early 2000s only used “informative” references to EN 954. I believe the main reason for this approach was because “EN” means that 954 was a European Norm which is a domestic European standard versus an international standard.

Reference without conformance

On the other hand, IEC and ISO standards have representatives from the U.S. on their committees so these standards are not country specific. Having said that, when NFPA 79; 2002 edition was published we included informational references to IEC 61508 and ISO 13849-1 but did not require conformance with these standards.

One reason this approach is often taken by a domestic standard committee in my opinion is because the international standard may include other requirements outside the scope of the domestic machine safety standard. Additionally, members of standards committees are traditionally slow to adopt large changes in practice regarding compliance.

Standards incorporation, integration, mergers  

So, where are machine safety standards headed? I believe that over the next 10 to 20 years we will gradually see:

  • More incorporation of international standards into U.S. domestic standards language.
  • More normative (required) references to specific parts of an international machine safety standard.
  • International standards also will evolve to a more global view representing the various industrial sophistication advancement levels around the globe.
  • More standards to merge,  to simplify and reduce complexities, as in the current case of merging IEC 62061 and ISO 13849 with expected completion by 2018 (see graphic).

However, one thing seems apparent – for the near term as I see it, we will continue to have both domestic U.S. and international machine safety standards for the next 10 to 20 years. U.S. compliance requirements could continue expanding to include international standards. And, this might already be the case should an industrial injury litigation case occur.

What is your opinion? Has your experience been similar or different? Add your comments or thoughts to the discussion by submitting your ideas, experiences, and challenges in the comments section below.

Related articles see the embedded link and scroll to the bottom for related coverage about:

Machine Safety – one global machine safety standard, is this real?

The increasing role of functional safety in complex machine design by Mark Nehrkorn

Machine Safety: 13 terms to know for compliance with functional safety, ISO 13849-1

The Buzz About ISO 13849-1: The Good, the Bad and the Ugly (and a Possible Alternate Solution) by Mike Carlson.

Contact: www.jbtitus.com for “Solutions for Machine Safety”.



For more than 30 years, J.B. Titus has advised a wide range of clients on machine functional safety solutions, including Johnson & Johnson, Siemens, General Motors, Disney, Rockwell Automation, Bridgestone Firestone, and Samsung Heavy Industries. He holds a Bachelor of Business Administration degree from Oklahoma University in industrial management and an MBA from Case Western Reserve University in marketing and finance. He is a professional member of the American Society of Safety Engineers and is OSHA-certified in machine guarding. Titus is also TUV-certified as a Functional Safety Expert and serves on several American National Standards Institute, National Fire Protection Association, and National Electrical Manufacturers Association national safety and health standards committees. Reach him at jb(at)jbtitus.com and via www.jbtitus.com.