Machine Safety: What differentiates a hazard analysis from a risk assessment?

With machine safety, why aren’t the differences well known between a Hazard Analysis and a Risk Assessment? It has been 12 years since machine safety jumped to the forefront of industrial opportunity.


Why aren’t the differentiations well known between a Hazard Analysis and a Risk Assessment in the application of machine safety? After all, it’s been 12 years since machine safety jumped to the forefront of industrial opportunity.


This question has really been confusing for a large part of the market for several years. In my opinion, only lately have some of the industry consensus standards begun to (subtly) draw out some distinctions. Maybe we can help via this blog.


I think there are several places to begin with the term – Hazard Analysis. OSHA defines hazard analysis as follows:


“What is a job hazard analysis?”
“A job hazard analysis is a technique that focuses on job tasks as a way to identify hazards before they occur. It focuses on the relationship between the worker, the task, the tools, and the work environment. Ideally, after you identify uncontrolled hazards, you will take steps to eliminate or reduce them to an acceptable risk level.”


Conversely, the machine safety consensus standards don’t directly address the term hazard analysis. In my experience over the past thirty plus years both the standards and best practices did their best to discuss hazards but did little to address and minimize hazards using a repeatable standardized process. So, in the early 2000’s when machine safety moved to the industrial forefront with bottom line opportunities, a process emerged called Risk Assessment. So, what is risk assessment?


The most recent ANSI B11.0; 2010 does a very good job of laying out risk assessment as a process and that Hazard Analysis is a sub part of the risk assessment process. The following two definitions are offered in this standard:


“3.69 risk assessment: The process by which the intended use of the machine, the tasks and hazards, and the level of risk are determined.”

“3.70 risk assessment process: The entire process of identifying hazards, assessing risk, reducing risk, and documenting the results (see Figure 5 in 6.1.3)”, below.

ANSI B11.0; 2010 -- 3.70 risk assessment process: The entire process of identifying hazards, assessing risk, reducing risk, and documenting the results (see Figure 5 in 6.1.3). Courtesy: ANSI B11


In my opinion, I would summarize the distinction between Hazard Analysis and Risk Assessment by asserting that Risk Assessment is the overall process whereby industry can identify and mitigate all known machine hazards to acceptable levels. The Hazard Analysis effort is then imbedded as a part of the overall comprehensive Risk Assessment process. Therefore, the Risk Assessment process includes the Hazard Analysis and is what develops the full machine safety hazard mitigation plan, validation, and documentation as shown above in the flow chart (Figure 5) from ANSI B11.0; 2010.


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 Safety: What differentiates a hazard analysis from a risk assessment? 


Related articles:

Machine Safety – does a risk assessment need to be updated for a minor modification to a machine?

Updating Minds About Machine Safety

Machine Guarding & The Hierarchy of Measures for Hazard Mitigation

Machine Safety – does OSHA reference consensus standards for compliance?


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