For shared bunded or contained areas storing two or more hazardous chemical containers/tanks, adequate containment is demonstrated where capacity is at least the greater of:
- 110% of the largest container/tank, or
- 25% of the total capacity of all containers/tanks.
For a single container/tank, containment must be at least 110% of that container/tank capacity.
Hydraulically linked tanks must be treated as a single tank.
Where local regulations or site-specific risk controls require a more stringent containment volume, these take precedence.
