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🚪 SOP-MIN-004: Confined Space Entry

Rule zero: No permit, no gas test, no standby person, no entry.

FieldDetail
Company / siteRidgeline Copper Operations (fictional sample company)
Document No.SOP-MIN-004
Revision1.0 (approved)
Effective2026-10-06
Next review due2027-10-06 (or after any incident or change)
Applies toAnyone who enters or supervises entry to tanks, bins, hoppers, sumps, mills, vessels and similar spaces
OwnerSite Safety Manager
Approved byMine Manager and Site Safety Manager

1. Purpose

To prevent deaths and injuries from toxic or oxygen-poor air, engulfment, entrapment and other hazards in confined spaces, and to make sure rescue is possible before anyone enters.

2. Scope

Any space not designed for continuous occupancy that has limited entry or exit and could contain a hazardous atmosphere or hazard.

3. Roles and responsibilities

RoleResponsibilities
Entry supervisorIssues the permit, checks the controls, cancels the permit when work ends.
EntrantEnters the space, stays in contact with the standby person, leaves at once on any alarm.
Standby personStays outside, tracks entrants, never enters, raises the alarm.
Gas testerTests and records the atmosphere before and during entry.
Rescue teamTrained and equipped for the specific space and on call during the entry.

4. Hazards and controls

HazardControl
Oxygen deficiency or enrichmentGas test, ventilation, continuous monitoring
Toxic or flammable gasGas test for the known contaminants, purge, isolate, ventilate, ignition control
Engulfment and entrapmentIsolate and lock out feed, clean the material out, fall protection and retrieval line
Heat, noise and poor visibilityTime limits, lighting, communication

5. Site-specific parameters

ParameterValue at Ridgeline Copper Mine
Atmosphere limitsOxygen 19.5% to 23.5%, flammable gas less than 10% of LEL, CO less than 25 ppm, H2S less than 10 ppm
Gas meters4-gas meters bump-tested daily and calibrated every 30 days (tag on the meter)
Permit formHSE-F-004, valid for one shift and one named space
Rescue teamOn-site emergency response team, 6 minutes to the concentrator, on Ch 9
Standby personTrained, with a radio and a copy of the permit; never enters
Typical spacesThickener tanks, ball mill, SAG mill, sumps, hoppers, surge bins
Maximum entry time60 minutes, then a break and a re-test

6. Procedure

Before entry

  1. Ask if entry is really needed. Remove the need where possible.
  2. Raise the entry permit and complete the hazard assessment.
  3. Isolate and lock out all energy, feed and process lines (SOP-MIN-014). Blank or disconnect pipes.
  4. Clean, drain, purge and ventilate the space.

Atmosphere test

  1. Test oxygen, flammable gas and toxic gas with a calibrated meter, from outside, at different levels.
  2. Record the readings. Entry is allowed only inside the permit limits.

Entry

  1. Brief the entrants, standby person and rescue team.
  2. Fit the retrieval gear and confirm communication.
  3. The standby person logs everyone in and out and keeps continuous contact.
  4. Continuous gas monitoring runs during the work. Leave at once on any alarm.

Closing

  1. Account for all people, tools and materials.
  2. Entry supervisor cancels the permit and removes the locks only after confirming the space is clear.

7. Stop-work triggers

Stop the job, make the area safe and call the supervisor if any of these happen:

  • Any gas alarm or reading outside limits
  • Loss of communication with the standby person
  • Ventilation fails
  • A change to the work or conditions
  • Anyone feels unwell

8. Emergency response

  1. Standby person raises the alarm and calls the rescue team. They do not enter.
  2. Use the retrieval line to pull the entrant out if possible.
  3. Only trained rescuers with breathing apparatus enter. Most deaths are would-be rescuers.
  4. Start first aid and call emergency services.

9. Records

  • Entry permits, gas test results and entry logs
  • Rescue plan and drill records
  • Entrant and standby training records

10. Related documents

  • Equipment isolation and lockout/tagout (SOP-MIN-014)
  • Emergency response and evacuation (SOP-MIN-007)
  • Job hazard assessment (JHA) template
  • Incident reporting and investigation SOP (SOP-MIN-010)
  • Applicable regulations for your jurisdiction, for example MSHA 30 CFR Parts 56 and 57 in the United States

Controlled document. The current version lives in this library. Printed copies are uncontrolled: check the revision before you use one. Questions or improvements go to the document owner.

11. Revision history

RevDateAuthorChange
1.02026-10-06Site HSE departmentFirst issue, approved for use

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