Confined Spaces: Never Go In After Someone

More than half the people who die in confined spaces are would-be rescuers. Somebody goes down, a workmate climbs in after them, and there are two victims instead of one. Everything about how these spaces are managed is built around stopping that.

What makes a space dangerous

A confined space is big enough to get into, has limited entry or exit, and is not designed for continuous occupancy — tanks, vaults, manholes, pits, silos, sewers, crawlspaces.

It becomes a permit-required space if it also has a hazardous atmosphere, a material that could engulf you, an inward-sloping or tapering shape, or any other serious hazard.

The atmosphere is what usually kills. It is invisible, it gives no warning, and low oxygen can put you down in one or two breaths. You cannot smell oxygen deficiency. You cannot hold your breath through it.

Before anyone enters

• Permit, signed, posted, listing hazards and controls.
• Test the atmosphere before entry and continuously during it — oxygen, flammables, then toxics, in that order.
• Ventilate, and keep ventilating.
• Isolate every line and energy source feeding the space.
• Rescue arranged before entry, not summoned after.

The three roles

• The entrant goes in, stays in contact, and gets out immediately if anything changes, an alarm sounds, or the attendant says so.
• The attendant stays outside. Always. They monitor conditions, keep count of who is in, keep unauthorised people out, and summon rescue.
• The entry supervisor authorises it, verifies the controls are in place, and terminates entry when the job is done or conditions change.

If someone goes down

Do not enter. Call rescue, use the retrieval line, keep everyone else out. That instruction feels wrong when it is your workmate on the floor of a tank, which is exactly why it is agreed in advance rather than decided in the moment.