Confined space entry is one of the most hazardous activities in any workplace. OSHA reports that confined space incidents cause approximately 100 fatalities per year, with an alarming proportion of those being would-be rescuers who enter without proper preparation. The permit-required confined space standard (29 CFR 1910.146) establishes a comprehensive program of pre-entry inspection, atmospheric testing, hazard control, and rescue planning that must be completed and documented before any entry. This guide covers the complete pre-entry inspection and equipment requirements with a free downloadable checklist.
Free Confined Space Inspection Checklist
Download our Word document pre-entry checklist covering atmospheric testing, hazard controls, equipment inspection, and permit documentation.
Download Checklist (.docx)Why Pre-Entry Inspections Are Required
OSHA 29 CFR 1910.146 — Permit-Required Confined Spaces
- 1910.146(c)(1): Employers must evaluate the workplace to determine if any spaces are permit-required confined spaces.
- 1910.146(d)(3): Before entry, implement measures to prevent unauthorized entry, identify and evaluate hazards, and establish acceptable entry conditions.
- 1910.146(d)(5): Test conditions in the permit space before entry and monitor the space during entry. Test first for oxygen, then combustible gases, then toxic gases.
- 1910.146(d)(9): Develop and implement rescue and emergency procedures, including designation of a rescue service.
- 1910.146(e): Entry permits must document all required conditions and be signed by the entry supervisor before entry is authorized.
Critical: Approximately 60% of confined space fatalities are would-be rescuers. Never enter a confined space to attempt rescue without proper training, equipment, and atmospheric monitoring. Calling 911 is not a rescue plan — employers must have designated rescue services or trained on-site rescue teams.
Atmospheric Testing
Test the atmosphere before entry, in the required order, from outside the space using calibrated direct-reading instruments.
| Test Parameter | Acceptable Conditions and Requirements |
|---|---|
| Oxygen (O₂) | Acceptable range: 19.5% to 23.5%. Below 19.5% = oxygen deficient (IDLH below 16%). Above 23.5% = oxygen enriched (fire/explosion risk). Test first before other readings. |
| Combustible gases (LEL) | Must be below 10% of the Lower Explosive Limit (LEL/LFL). Test second, after oxygen is confirmed acceptable. Readings above 10% LEL require additional ventilation or prohibition of entry. |
| Toxic gases — H₂S | Hydrogen sulfide: below 10 ppm (8-hour TWA PEL). Ceiling limit 50 ppm. Extremely dangerous — olfactory fatigue occurs rapidly, making smell unreliable above 100 ppm. |
| Toxic gases — CO | Carbon monoxide: below 50 ppm (8-hour TWA PEL). Common in spaces with combustion sources, decomposing organic material, or connected to vehicle exhaust areas. |
| Other toxic substances | Test for any additional contaminants identified in the hazard evaluation specific to the space. This may include ammonia, chlorine, SO₂, VOCs, or other process-specific gases. |
| Instrument calibration | Gas monitor calibrated per manufacturer requirements (typically daily bump test, full calibration at regular intervals). Calibration records current and available. |
Hazard Controls and Isolation
| Inspection Item | What to Verify |
|---|---|
| Energy isolation (LOTO) | All energy sources locked out and tagged out per 1910.147. Electrical, mechanical, hydraulic, pneumatic, chemical, and thermal energy sources identified and controlled. |
| Line breaking/blanking | Pipes and lines that could introduce hazardous materials are disconnected, blanked, blinded, or double-blocked and bled. No gravity feed pathways remain open. |
| Ventilation | Mechanical ventilation in place and operating. Air supply from a clean source. Ventilation continuous during entry. Ductwork positioned to reach all areas of the space. Note: forced air ventilation alone does not eliminate atmospheric hazards for reclassification purposes. |
| Inerting/purging | If the space was inerted for cleaning, atmosphere has been restored to breathable levels before entry. Purge procedures completed and documented. |
| Physical hazards | Engulfment hazards controlled (material removed or barriers in place). Moving parts secured. Fall hazards addressed. Hot surfaces identified and guarded or cooled. |
| Barriers and signage | Permit space posted with "DANGER — Permit-Required Confined Space, Do Not Enter" or equivalent. Unauthorized entry prevented by barriers, covers, or other means. |
Equipment Inspection
| Equipment | Inspection Items |
|---|---|
| Gas monitors | Calibrated and bump-tested. Sensors not expired. Alarms set to correct thresholds. Battery charged. Functioning properly in fresh air before use. |
| Ventilation equipment | Blower or fan operational. Ductwork intact with no holes or kinks. Adequate CFM for the space volume. Power supply reliable. |
| Retrieval system | Tripod or davit arm stable and rated for the load. Winch functions properly (raises and lowers). Retrieval line in good condition. Full-body harness inspected per fall protection requirements. |
| Communication equipment | Radios or hardwired communication tested between entrant, attendant, and entry supervisor. Backup communication method available. |
| Respiratory protection | If required: SCBA or supplied-air respirator inspected, tested, and fit-checked. Escape SCBA or emergency escape breathing apparatus available as needed. Air supply duration adequate. |
| Lighting | Explosion-proof or intrinsically safe lighting for atmospheres at or above 10% LEL. Adequate illumination for the work to be performed. |
| PPE | Hard hat, safety glasses, gloves, and protective clothing appropriate for the hazards. Chemical-resistant PPE if chemical exposure is possible. |
Personnel and Rescue Readiness
| Requirement | What to Verify |
|---|---|
| Entry supervisor | Designated entry supervisor on site. Authorized to issue permits. Knows the hazards and can cancel the permit if conditions change. |
| Authorized entrants | All entrants trained per 1910.146(g). Know the hazards, symptoms of exposure, proper equipment use, and how to alert the attendant. Training current. |
| Attendant | Designated attendant stationed outside the space for the duration of entry. Knows hazards, maintains count of entrants, can order evacuation, and will not enter the space for rescue. |
| Rescue service | Rescue service identified and available. On-site rescue team equipped, trained, and has practiced within the past 12 months. Off-site rescue: response time evaluated and deemed timely. Contact information on the permit. |
| Training currency | All personnel (entrants, attendants, entry supervisors, rescue team) trained before initial assignment and when duties change, hazards change, or performance indicates inadequate knowledge. |
Entry permit requirements: The entry permit per 1910.146(f) must document: the space to be entered, purpose of entry, date and authorized duration, authorized entrants, attendant(s), entry supervisor, hazards of the space, measures to isolate and control hazards, acceptable entry conditions, test results, rescue and emergency services, communication procedures, required equipment, and any additional permits (hot work, etc.).
Program Review
Annual Program Review
- Review the permit space program within one year after each entry using canceled permits
- Evaluate whether procedures adequately protected entrants from space hazards
- Identify any deficiencies in the program and revise procedures as necessary
- Update the confined space inventory when new spaces are created or conditions change
- Verify rescue service capability and response time remain adequate
- Ensure all training records are current for authorized entrants, attendants, and supervisors
Download the Free Checklist
Get our confined space pre-entry checklist in Word format. Customize for your site-specific permit spaces and procedures.
Download Checklist (.docx)
Go digital with Ecesis. Replace paper confined space permits with Ecesis inspection software. Manage your confined space inventory. Issue digital entry permits with atmospheric readings and electronic signatures. Schedule annual program reviews. Track entrant, attendant, and rescue team training. Request a free demo.
Ecesis EHS Software
Inspections
Digital confined space permits with atmospheric readings and electronic sign-off.
Safety Inspections
Workplace inspections with confined space signage and barrier verification.
Training
Track entrant, attendant, entry supervisor, and rescue team training records.
Preventive Maintenance
Schedule gas monitor calibrations, equipment inspections, and rescue drills.
Compliance Calendar
Track annual program reviews, rescue drill schedules, and training renewals.
Task Management
Assign corrective actions from program reviews and track to completion.
