Confined space permit: what does it cover?

A confined space has limited entry and exit, weak ventilation and was not designed for continuous work. Tanks, boilers, ducts, silos and pits are typical examples. A separate permit is requested for work there because the danger is often not visible from outside.

Why a separate permit?

Oxygen can run low, and toxic or flammable gas can build up. If something goes wrong it is hard to reach and remove the person inside. So preparation and checks are put in writing before the job starts.

What does a permit usually contain?

• Description of the space, the purpose of the job and its duration
• Names of the people entering and of the attendant who waits outside
• Ventilation and, where needed, gas measurement with results
• Isolation measures such as shutting off and locking energy and fluid lines
• The rescue method and communication to use in an emergency
• Signatures of the people who approve and check

Typical steps

1. The contractor prepares the permit request with the space, the job and the personnel.
2. EHS checks the space and the preparations.
3. Measurements and isolation are done before the job, and the results are entered on the form.
4. During the work the attendant outside stays in contact with the person inside.
5. When the job ends the space is cleared and the permit is closed.

Common gaps

Measuring only at the start and not repeating while work continues, an attendant being pulled away to another task, and people entering who are not named on the permit are frequently seen gaps.