Confined Space Checklist

Work the checklist below: the permit header, the gas test with the live limits (the tool checks each value and writes the pass or the fail), the isolation, the attendant duties, the rescue plan, and the medical fitness questionnaire. Print the completed checklist as the entry record — the document the attendant holds and the investigator opens.

How to use the tool

1. Complete the permit header — the space, the purpose, the entrant, the attendant, the time, the issuer
2. Isolate the space — the blind, the valve, the LOTO, the water and the steam, the electrical: the isolation table, all of it
3. Test the atmosphere — the O2, the LEL, the CO, the H2S at the point of entry and at depth: enter the values and the tool checks the limits
4. Set the attendant and the rescue — the attendants duties, the rescue plan, the retrieval, the breathing apparatus, the drill
5. Check the medical fitness — the questionnaire below; any yes is the doctors decision before the entry — then print and post the checklist

Worked example

A tank cleaning entry: the space the day tank, the purpose the internal clean, the entrant the cleaning contractor, the attendant the site operator, the issuer the shift supervisor. Isolation: the inlet and the outlet blinded (the blind certificate), the drain valve locked, the electrical to the pump isolated and tagged, the water to the wash-down isolated. Gas test at the entry and at depth: O2 20.8 (pass), LEL 0 (pass), CO 3 (pass, under 30), H2S 2 (pass, under 10) — the tool marks all four. Ventilation: the forced ventilation running, the air supplied to the entry, the reading at the mid-depth re-checked at 30 minutes. Attendant: posted at the entry, the radio, the rescue line, the no-entry-without-rescue rule briefed. Rescue: the tripod and the winch set, the BA set at the entry, the drill run at the last entry, the local emergency the alarm and the muster. Medical: the entrants questionnaire — all no, the last check 3 weeks ago, fit. The checklist is printed, posted at the entry, and the attendant holds the copy. That is the entry that holds.

Standard & legal context

The UK ACoP L117 and the HSE INDG101 family set the method: the avoidance first, then the control — the permit, the test, the isolation, the ventilation, the attendant, the rescue. The US pair is the OSHA 1910.146 (the Permit-Required Confined Spaces standard) and the HAZWOPER 1910.120 — the 1910.146 is the explicit permit standard, with the attendant and the rescue the named requirements. The gas limits are from the UK and US practice (the OSHA ceilings, the UK 15-min values). The checklist below is the 1910.146 structure with the UK columns.

Common mistakes

1. Testing at the door and not at depth — the gas stratifies: the heavy gas (the H2S, the CO2) at the bottom, the light at the top; the entry and the depth are both tested
2. The attendant who does the work — the attendants job is the watching, the radio, the alarm and the rescue call; the attendant who enters to help is the attendant gone, and the entrant alone
3. No rescue plan, or the we-will-call-the-fire-brigade plan — the rescue is planned, drilled and equipped at the entry; the 3-minute rule is why (most rescuers die saving the entrant)
4. Skipping the medical — the confined space takes the fit person; the questionnaire is the screen, and the yes is the doctor, not the supervisor, who decides