The regulations state:
'No person at work shall enter a confined space to carry out work for any purpose unless it is not reasonably practicable to achieve that purpose without such entry.' See also equivalent devolved legislation.
If objectives can be achieved without entering the confined space, the risk of injury to personnel and worsening of conditions (e.g. disturbance of sludge) in the confined space are significantly reduced. It is vital to assess the confined space to establish the risks presented by entry in comparison to the benefits of doing so.
All personnel should be aware of the limitations of their knowledge, training and equipment so they can assess the risk and make an informed tactical decision and intervention.