Describe a situation in which an entrant discovers a new hazard within a confined space, explaining the actions required to stop work, re-evaluate the space, and ensure safety before resuming entry operations.

Discovering a new hazard within a confined space requires immediate action to protect the safety of all personnel. A well-defined procedure must be followed to stop work, re-evaluate the situation, and implement necessary controls before resuming entry operations. The key is to prioritize safety above all other concerns, and to have a systematic process in place to deal with unexpected events. Let’s consider a scenario where a team is performing routine maintenance inside a large, empty storage tank that has previously been cleaned and tested. Two entrants, John and Mary, have entered the tank wearing proper personal protective equipment (PPE), including respirators, and are in constant communication with the attendant outside, Sarah. All atmospheric tests have been previously completed, and the atmospheric readings are all within acceptable limits. The team has followed all proper procedures, and they are working according to the pre-entry plan. During their work, John is inspecting a previously inaccessible corner of the tank, and discovers a small, corroded area on a pipe that appears to be leaking a liquid. This liquid was not part of the previously identified materials, and it was not anticipated during the pre-entry plan. As soon as John notices the leak, he immediately communicates this discovery to the attendant, Sarah, using their two-way radio, stating "Sarah, this is John, I have found a previously unnoticed leak on a pipe in the south-east corner, the liquid is unknown and I am stopping all work." Sarah immediately alerts the supervisor, Tom, about the situation, stating, "Tom, this is Sarah, John has discovered a new leak on a pipe in the tank, the liquid is unknown and he has stopped ....