29 C.F.R. § 1926.1205 – Permitting process.

(a) Before entry is authorized, each entry employer must document the completion of measures required by § 1926.1204(c) by preparing an entry permit.
(b) Before entry begins, the entry supervisor identified on the permit must sign the entry permit to authorize entry.
(c) The completed permit must be made available at the time of entry to all authorized entrants or their authorized representatives, by posting it at the entry portal or by any other equally effective means, so that the entrants can confirm that pre-entry preparations have been completed.
(d) The duration of the permit may not exceed the time required to complete the assigned task or job identified on the permit in accordance with § 1926.1206(b).
(e) The entry supervisor must terminate entry and take the following action when any of the following apply:
1. (1) Cancel the entry permit when the entry operations covered by the entry permit have been completed; or
2. (2) Suspend or cancel the entry permit and fully reassess the space before allowing reentry when a condition that is not allowed under the entry permit arises in or near the permit space and that condition is temporary in nature and does not change the configuration of the space or create any new hazards within it; and
3. (3) Cancel the entry permit when a condition that is not allowed under the entry permit arises in or near the permit space and that condition is not covered by paragraph (e)(2) of this section.
(f) The entry employer must retain each canceled entry permit for at least 1 year to facilitate the review of the permit-required confined space program required by § 1926.1204(n). Any problems encountered during an entry operation must be noted on the pertinent permit so that appropriate revisions to the permit space program can be made.