Critical Control

A control, in this context, is something that is put in place to prevent, arrest, or mitigate unwanted events. A critical control is a control which:

• applies to an event that is considered critical, by way of being classified as a 'Material Unwanted Event' (MUE) or 'Priority Unwanted Event' (PUE)
• will result in a significant increase in risk, if it fails, despite the presence of other controls
• controls for a multitude of unwanted events

An example of a critical control is a fire suppression system on an oil rig, because it satisfies the first two criteria above.