The New ISO 12100 – Safety of Machinery

by Bruce W. Main, PE, CSP. Design Safety Engineering, Inc. By AIAG.org, October 2008.
Posted 11/16/2008

ISO 12100 is a fundamental safety standard being developed that will apply to a very broad array of machinery.  There are many machines that have specific industry consensus standards that pertain to the particular equipment (e.g., power presses, robots, packaging machinery).  There are many more machines for which no industry specific standard exists.  In this case, the ISO “A level” standard ISO 12100 Safety of Machinery applies. 

ISO, ANSI, CEN, ASTM, SAE, CSA, AS/NZS … the list of national and international standards seems never ending and always changing.  As a result, standards and regulations continue to create significant challenges for AIAG members in identifying, understanding and applying the requirements of the many standards.

AIAG members move equipment and machinery between national and international regions to optimize production.  Layers of different standards and regulations can lead to significant wastes in terms of delay related to equipment transit and obtaining approvals from necessary authorities.  In addition, retrofitting machinery guarding to meet differing safety requirements of specific regions often adds costs and little value.  Harmonizing requirements in the standards facilitates quick and easy movement of equipment, and helps minimize wastes of many kinds.

 “He who controls the industry standard controls commerce” is a truism of our time.  AIAG members currently working through the nest of environmental and chemical requirements coming from the EU are all too familiar with this reality.  Similarly, the control of industry safety standards is proving to be critically important with machinery safety.

ISO 12100 Safety of Machinery

ISO 12100 is a fundamental safety standard being developed that will apply to a very broad array of machinery.  There are many machines that have specific industry consensus standards that pertain to the particular equipment (e.g., power presses, robots, packaging machinery).  There are many more machines for which no industry specific standard exists.  In this case, the ISO “A level” standard ISO 12100 Safety of Machinery applies.  Complying with the requirements of ISO 12100 is a critical first step in achieving mobility of equipment and consistent operations.

Prior to the drafting of ISO 12100, there were three distinct and separate standards that addressed what is essentially one process:  ISO 12100-1 (hazard identification), ISO 12100-2 (risk reduction), and ISO 14121-1 (risk assessment).  Cutting up the process into three separate standards was originally necessary for political reasons in the early 1990s.  Without this construction there were concerns that no standard would ever have been approved.  The unfortunate consequence was that this tripartite construction introduced several technical difficulties or inconsistencies and led to inefficiencies and wasted time, effort and motions for users of the standards, and for the standards writing committees.  Even something as simple as flipping between documents is an unnecessary waste.  For standards writers, this tripartite construction resulted in additional meetings and unnecessary discussions about barriers from the separation of content.  For example, the tripartite format led to ridiculous artificial limitations such as the inability to discuss risk reduction in the ISO 14121 risk assessment standard – even when everyone agreed the only reason to do risk assessment is to reduce risk.  As technology changes evolved, each standard attempted to address and incorporate changes in due course.  But the revisions were not in lock step thus substantial problems arose when changes made to one standard were inconsistent with the other two.

ISO 12100-1 and -2 were reissued as revised documents in 2003.  Subsequent to that time, an effort to revise ISO 14121 (risk assessment) commenced in 2004.  The U.S. had great hopes at the time to update the document with current knowledge gained in applying the risk assessment process.  What eventually became clear to the U.S. delegation was that the ability to modify the primary standard was very limited, largely due to the artificial constraints of the tripartite construction.

U.S. Innovation

To address this problem, the U.S. began to examine how to combine the content of the three distinct standards into a single document.  The idea was raised at a meeting of the ISO Technical Committee 199, Working Group 5 (WG5 – Risk Assessment) in late 2004.  The majority of TC 199 Member country participants balked at the idea of combining the requirements of risk assessment and risk reduction. “It will not happen” was the predominant sentiment.

One reason for resistance stemmed from the structure of the ISO standards.  The ISO A-B-C level organizational structure follows.
• Type-A standards (basis standards) give basic concepts, principles for design, and general aspects that can be applied to machinery;
• Type-B standards (generic safety standards) deal with one or more safety aspects or one or more types of safeguards that can be used across a wide range of machinery:
• Type-C standards (machinery safety standards) deal with detailed safety requirements for a particular machine or group of machines.

In the case of ISO 12100-1 and -2, there are approximately 800 Type B- and C- standards that reference the content of these two A level standards.

However, the idea made sense to members of the U.S. delegation and another opportunity soon presented itself.  The primary standard for the packaging machinery industry, ANSI/PMMI B155.1, was due for a revision.  A draft revision of the standard was prepared that integrated the risk assessment process with the technical requirements for packaging machinery.  The B155.1 standard committee diligently worked on the document resulting in the April 2006 publication of ANSI/PMMI B155.1:2006.

As the packaging machinery standard was nearing completion, a second opportunity arose in the B11 machine tool industry.  The B11 community needed to retool its standards development process and decided to leverage the progress made in B155.1.  A new B11 standard writing subcommittee was formed and modified and further improved the ground-breaking work of B155.1.  In August of 2008, the ANSI B11 standard addressing the general safety requirements and risk assessment/risk reduction for machines, machine tools, and machine tool systems was formally approved as a new American National Standard.

Both of the ANSI standards B155.1 and B11 are currently being used by machinery suppliers and users in the U.S. to build safer and productive machinery.  Feedback from these communities is that the standards are working very well.

Re-engaging the International Stage

Based on the successes of B155.1 and ANSI B11, the U.S. re-introduced the concept of a single, integrated safety of machinery standard in early 2007.  A proposal was made to pursue a two step approach.  The first step was to be an editorial combination of the existing three standards.  Combining existing and approved text without technical changes into a single standard leaves limited room for controversy or objection.   The second step, which may or may not occur any time soon, would be the technical revision of the merged document.

By early 2008 the same WG5 participants that had initially opposed a merged document had changed their position to espousing that not only could the combination be done, but “it should be done.”  At the 2008 October meeting in Germany, WG5 resolved remaining comments on the document and approved its promotion to the Draft International Standard (DIS) stage of development.  The DIS version will be circulated to member countries for one last round of technical review and comment.  A meeting is scheduled for September 2009 to resolve any comments after which the document will work through the remaining editorial approvals.  Since no technical changes are being considered in the current activity, the standard is expected to advance through to approval rapidly.  Publication is currently expected to occur in early 2010.

A key element to the success of this effort is the two step process.  The first step, the editorial combination of the three standards, was accomplished at the Committee Draft level at the recent meeting in Waldkirch, Germany on 6-8 October 2008.

Through the efforts of the U.S. participants, the current draft standard combines these three distinct standards into one new ISO 12100 – which provides one place, one flow, one base for addressing what is essentially a single process – identifying hazards, assessing risks and reducing them.  The intent is that this standard will help bring the world closer to harmonizing where suppliers and users can build to one standard and then ship machinery anywhere.

Although there seems to be technical limitations with the current draft of ISO 12100, there is little appetite to initiate the technical revision any time soon.  There is recognition that some time is necessary for readers to fully understand the changes made in step one, and that the stability of this key A-level standard would benefit from a delay before initiating the technical revision.  If, or when, a technical revision does commence, the U.S. will strongly advocate for consideration of key elements from the ANSI B11 and ANSI/PMMI B155.1 standards.

AIAG’s Role

Leadership at the ISO level requires: a) the ability to participate in an on-going effort, b) the practical knowledge of what is and is not needed, and c) participation beyond one or two meetings. Long term participation is critical to building international support for the participants and the ideas they promote.


AIAG’s Safety, Health & Environmental Steering Committee and the other U.S. participants recognized very early the critical importance of the ISO 12100-1, -2 and 14121 standards to the long range future of AIAG members. Through AIAG support and participation, the U.S has been able to significantly influence the content of the standard. AIAG supported leadership has been very active and influential in the work of the WG5.
Unfortunately, the U.S. has had a fairly long history of arriving late to the standards development table and expecting the ISO world to change in response to its concerns. This approach has not been very successful. In many instances the “late to the party” approach has led to minimal influence on the resulting requirements and considerable alienation of other participants who have made the effort to participate at the formative stages of standards development. As many AIAG members have come to realize, the real opportunity to influence an industry standard occurs in the very early, formative stages.
“The best defense is a good offense.” In the ISO arena, the offense occurs in introducing safety methods and practices that have proven effective in the U.S. Similarly, the defense aspect is to keep unworkable ideas and requirements out of international standards that are proposed by others less familiar with the practical aspects of risk assessment or which would cause problems in U.S. applications.
With AIAG foresight and support, the U.S. has been able to significantly influence the content of the ISO 12100 standard and register success for U.S. manufacturers. The U.S. has provided a significant dose of practical knowledge in crafting ISO 12100. Since the U.S. has already combined the elements of these three individual standards not once but twice, the more time that passes before a technical revision only lends credibility and a strong strategic advantage in a very important area to U.S manufacturing interests.
Based on benchmark practices learned through participation in the work of WG5, the U.S. is in a lead position of applying the principles of the risk assessment process. AIAG members and other U.S. manufacturers are seeing significant productivity improvements and competitive advantages from a simple, harmonized approach to machinery safety. The improved ISO 12100 standard is expected to help AIAG members in achieving mobility of equipment, consistent operations and to complete in the global marketplace.

Readers interested in current best practices should obtain copies of B155.1 and B11. Meeting the requirements of these standards will also meet the requirements of the forthcoming ISO 12100, and help improve machinery safety and productivity.

Bruce Main, PE CSP participates on the AIAG EHS Steering Committee and is the Convenor (Lead) of the ISO TC199 Working Group 5. Contact him with questions at [email protected]

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