Hierarchy of Control Measures

A standardization of the mode of Occupational Safety and Health (OSH)-related hierarchy of control measures can make the learning process of the training realm more effective and efficient. When researching many OSH-training-oriented and/or OSH-examination-centered businesses, such as NSC, OSHAcademy, NEBOSH, CIEH, IOSH, and so forth, I found many have created their own curricula within training processes based on do-it-yourself mode resulting in disharmony in contents selected to be delivered to the target audience.  This can obviously be seen when addressing many issues and terminologies pertaining to occupational safety and health.  Here are a few examples:

  • incidents vs. accidents
  • categories of hazards
  • hierarchy of control measures

However, the issue here is not to restrict the promotion of the creativity in the training process rather than emphasizing the application of unified terms, concepts, illustrations and categorization on different OSH subjects.

Having been a part of OSH training as a learner or trainer with specialized international organizations in occupational safety and health, it is easy to be confused by numerous interpretations of used concepts, terms, definitions, and meanings.  This includes the pattern of how you portray the associated figure of the hierarchy of the control measures.

Let’s use these comparisons to take a closer look at the interpretations:

  1. The NEBOSH’s teaching/training approach of “the hierarchy of control” is depicted in this pattern (eliminate, reduce, isolate, control, PPE and discipline)
  2. CIEH’s follows this tactic (elimination or avoidance, substitution, controlling risks at source, safe working procedures, training, instruction and/or supervision and PPE)
  3. In addition, NSC tends to shorten stages into (engineering, administrative and PPE controls)
  4. IOSH’s embraces this hierarchy (eliminate the hazard, reduce the hazard, prevent people coming into contact with the hazard, introduce a safe system of work and provide PPE)

Not only could these distinctions be highlighted,  but also different meanings of the control measures wording were used variously by individual organizations.  For instance, the elimination is used by both IOSH and NSC in equivalent to the replacement/substitution.  On the other hand, NEBOSH uses it as a strategy usually considered at the planning stage of the operation in order to avoid potentially substantial costs.

To overcome the confusing and proliferating problem of non-unification of the mode of the hierarchy of control measures, there needs to be some sort of standardization of the language and representing drawings that are used.  Language standardization is regarded as one of the most meaningful approaches to satisfy this aim.  In fact, the language standardization has many benefits from a business’ point of view.  It creates simplicity and professionalism, with clearer branding, improvement of user experience, and software localization.


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Although there is a tremendous number of benefits from standardization, there have not been any tiny initiatives put into place to deal with these undoubtedly protruding differences in relation to the hierarchy of control measures. In fact, the hierarchy of control measures can be addressed from different angles in terms of categorization, associated drawings, wording, and prioritization. I would suggest one idea that can be adopted as a standard to overcome different discrepancies (See Figure 1).  However, it is drawn upside-down to reflect the effectiveness of each level based on the size of occupied area in relation to the overall triangle area.  As you can see, personal protective equipment is on the bottom.  This is because, I believe, PPE should be the last resort when thinking about controlling the risks of different hazards. In addition, one extra level of control (called avoidance) is added at the top level.  This reflects and encompasses the important planning process that needs to be considered at the conception stage of any work activity.  This takes the place of elimination and removal controls which normally fall after this level.

In conclusion, providing some standardization in hierarchy of control measures would promote consistency, diminish complexity, drive out ambiguity, as well as create quality control objective criteria.