As part of a comprehensive ammonia risk analysis, Technical Safety BC developed a fault tree to visualize different failure scenarios that can result in the uncontrolled release of ammonia from ammonia refrigeration systems. This fault tree is foundational for characterizing each ammonia incident in BC and helps us identify the most prominent scenarios to be addressed through our risk treatment plan.

From September to October 2025, we engaged on a draft version of the fault tree to identify areas requiring clarification, and additional scenarios that may have been missing.

We plan to create further opportunities to engage on the risk treatment actions for uncontrolled ammonia release.

CLOSED: This survey is now closed. Read our What We Heard report for a summary of the feedback we received.

Survey: Uncontrolled Ammonia Release Fault Tree

Please complete this survey by October 2, 2025 (5 pm).

In this survey, we will ask you to review the ammonia release fault tree and see if:

1. Any failure scenarios are missing; and
2. Any of the existing scenarios are unclear/ambiguous.

If you are not familiar with fault trees, please watch the short video tutorial that describes how to read a fault tree.

NOTE: We encourage you to complete this survey in one sitting, but if it's not possible, please keep this page open on your browser (it will not time out) until you are ready to submit it. Do not click on the survey link again as that will remove your current responses.

View the ammonia release fault tree

Watch the video tutorial on how to read fault trees