Entry into enclosed spaces is considered an extremely dangerous activity and has been the cause of many accidents involving fatalities in the past. Chapter 17 of the Code of Safe Working Practice provides detailed information regarding correct procedures to adopt.
In any event it would be expected that the following actions and precautions are adopted:
(a) A ‘risk assessment’ of the activity must be carried out prior to entry.
(b) The recommended checklist, within the ‘permit to work’ should be adhered to.
(c) The atmosphere of the intended space for entry must be tested for oxygen content and the presence of toxic gases.
(d) The space must be vented in every case and the ventilation system must be seen to be adequate.
(e) Reduce the number of persons on the activity to only those persons deemed as essential to carry out the intended task.
(f) Designate a ‘stand-by man’ to be stationed outside the entrance of the space in order to raise the alarm in the event of problems being incurred by the work party once inside the space.
(g) Post the ‘permit to work’, copy at the entrance of the space.
(h) Ensure that the space is adequately illuminated prior to entry being allowed.
(i) Resuscitation equipment should be readily available for emergency use at the entrance to the space.
(j) Test communications between the stand-by man, and the work party before and after entry is made (communication equipment and torches should be intrinsically safe in their operation).
(k) Emergency alarms and communications should be clearly understood by all persons concerned with the operation.
In the event entry is to be made with Self-Contained Breathing Apparatus (SCBA), full precautions and safety checks must be made in conjunction with the wearer. Once the task is completed the permit to work must be cancelled.