Autopro Blog

CHAZOP Webinar Q&A

March 12, 2018


Our recent webinar, Introduction to CHAZOPs, resulted in some great questions being asked by participants. Here are a few that we thought would be especially informative for many of you.


How do you justify a CHAZOP if a HAZOP is done at regular intervals?

The difference between a HAZOP and a CHAZOP is the HAZOP assumes that the control system is operational and it is working. A CHAZOP looks beyond that and into the control system, and determines if your network, remote I/O network or your peer to peer network is working or what happens if they fail. It is generally recommended that a HAZOP be conducted at regular intervals; the IEC standard is approximately every 5 years. However, a CHAZOP may not need to be done that often, although it is always good practice to conduct one as part of an upgrade or an expansion to an existing system.

Is there any industry code or regulation that addresses CHAZOP requirements?

There is no specific code or regulation that states the requirement for a CHAZOP. However, in Canada there is a requirement for workers to understand the risk associated with their job. Operators should know, or be provided with the opportunity to learn and understand, the risks that they face in their jobs. You can think of a CHAZOP as an extension of a job hazard analysis (JHA), which is part of standard workplace safety assessments. The purpose of a JHA is to identify potential hazards before they occur, allowing you to take appropriate steps to reduce or eliminate the risk of them occurring. The CHAZOP identifies potential hazards within the control system and allows the Operator to take the appropriate measures to reduce or eliminate that risk.

Throughout the presentation, the examples of a CHAZOP recommendation show the need to install a redundant item.  Would it be safe to assume that the current thought is to install a complete redundant system?  That could prove very costly.

You don’t need redundancy everywhere, rather, we are trying to identify is if there is a critical area that should have redundancy built in. For example, a process that is looking at the feed into your facility would be critical.  Without that process, you would have lost time. Alternatively, if you look at a packaging unit or a unit where there’s lots of storage such as truck loading, it may be lower priority, therefore it may be acceptable to have an outage. Conducting a CHAZOP will help you identify both types of scenarios. Once you know which areas are high priority and high risk versus low priority and low risk, then you can determine where best to invest capital to manage the risk.

Do you have other questions about conducting a CHAZOP? Feel free to contact us for assistance.

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