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Transitioning from OHSAS 18001 to ISO 45001 (Part 2)

Updated: Feb 13, 2022

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Part 1 of this series focused on 3 differences between OHSAS 18001 and ISO 45001.  Here we’ll focus on the remaining 5 differences with some ideas on how to implement them.

The first 3 differences included:  Top Management Commitment, Delegation of H&S Responsibilities and Culture.  The last 5 differences between the two standards are: Annex SL, Risk & Hazards, Improved Planning, “Health” Definition and updated Terminology.

Annex SL:  High Level Structure (HSL) which simplifies language within other ISO and international standards so that language is consistent.  This should make it easier to integrate other management systems. Being able to understand Annex SL is imperative for ISO. Annex SL also replaces Guide 83.  For more information on Annex SL system, click here.

Risks & Hazards:  The OHSAS 18001 focuses on controlling hazards.  The ISO 45001 is more geared towards analyzing, controlling and identifying risk, and evaluating the entire process.  Risk-Based Control can identify deeper issues a lot sooner than just controlling hazards. It’s a look into overall root cause, and scope; a “holistic approach” prior to hazards surfacing. A simple example would be fall protection while working on a piece of equipment or something similar.  Instead of identifying the hazard and controlling it, risk control is going to:

  1. Look back at the scope of the job

  2. Ask if it is necessary to work on the roof

  3. Identify ways to control the work without fall protection being an issue, such as personal fall protection vs a guardrail system.

Improved Planning:  strategic planning is crucial and more explicit in ISO 45001 than OHSAS 18001.  Any Health and Safety Objective should follow some sort of format to state the goal, the measurable or metric, have a responsible person, and have a time, length, or date associated with the completion of the goal.  SMART Objective Planning, or something similar, is a great planning technique.


Health:  ISO 45001 has not unequivocally mentioned mental health, but Human Factors such as Fatigue and Mental Health are being more talked about among organizations and ISO 45001 gives them flexibility within the system to address mental health if needed.

Terminology:  There are over 30 new terms used in the updated standard.  Words such as “worker” vs “workplace” give the system a wider approach. Understanding the terms is crucial in the success of ensuring certification within the new system.


All in all, Safety & Health Standards have been proven over and over to be the most effective and efficient way to design a process for ultimate results, thus reducing risks, injuries and incidents.  Despite the new requirements to the ISO 45001, the goal of having any Health & Safety Management Process remains the same: “reduce unacceptable risks and ensure the safety and wellbeing of everyone involved in an organization’s activities”.  Transitioning to the new ISO 45001 Standard must be done with intentionality and excellence as it requires attention to detail and a well organized and dedicated team.

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