For this purpose, risks or concerns can be banded into three distinct levels:
- acceptable risk - a risk which is regarded as low
- tolerable risk - a risk which is not regarded as low, but is considered worth taking (there is a willingness to live with the risk). To tolerate a risk means that we do not regard it as negligible, or something we might ignore, but rather as something we need to keep under review, and reduce still further if and as we can.
- unacceptable risk - a risk which can not be justified
In practice, the majority of risks fall in the tolerable region, in which case they should be managed so that they are as low as reasonably practicable.