Machine guarding and the hierarchy of measures for hazard mitigation

Do you know the five levels of hazard mitigation? Machine guarding isn’t completed task that’s checked off a list. Eliminate, isolate, add engineering, implement controls, and use PPE, then repeat.


JB Titus, CFSEIndustry is learning about the “hierarchy of measures” for hazard mitigation as more work is accomplished on the changing landscape of machine guarding. None of these measures are new to industry. However, documenting the process and organizing your thoughts is somewhat new. Do you know what the five levels are for hazard mitigation?

Control Engineering machine control - robotic iconMachine guarding is a process and not an event. As a result of innovation the most effective machine guarding can now begin in the design stage and no longer needs to be an afterthought and added during installation. Hence, the process begins with the risk assessment to identify all of the hazards. It’s at this stage that the hazards can be eliminated with the least cost or investment. Therefore, the process of hazard mitigation begins at this point. In many cases the design phase continues and so does the hazard identification and hazard mitigation. This is why it’s important to know, understand, and practice the risk assessment requirement as a living process and document.

So, what are the five levels of hazard mitigation in machine guarding?

1) Eliminate the hazard – design it out

2) Isolate the hazard with hard guarding

3) Add additional engineering, guards, devices, or layers of safety

4) Implement administrative controls like – training, signage, assessments, etc.

5) Use personal protective equipment (PPE) like - goggles, gloves, outer clothing, shields, etc.

All five levels are fully acceptable risk mitigation solutions to achieve that “acceptable” level of mitigated risk. In my opinion, that acceptable level of risk for a given hazard is intentionally left undefined because you are the one who defines the tolerable level of risk you’re willing to accept.

Is this process working in your safety culture?

Your comments or suggestion are always welcome so please let us know your thoughts. Submit your ideas, experiences, and challenges on this subject in the comments section below. Click on the following text if you don't see a comments box, then scroll down: Machine Guarding & The Hierarchy of Measures for Hazard Mitigation

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