Non Permit-Required Confined Space Checklist

What this checklist is for

A confined space is an area that is large enough for a person to enter and work in, has limited or restricted means of entry or exit, and is not designed for continuous occupancy. A non permit-required confined space is one that has been assessed and found not to contain, or have the potential to contain, a hazardous atmosphere, a material that could engulf an entrant, an internal configuration that could trap or asphyxiate an entrant, or any other recognized serious safety or health hazard. That status is a conclusion, not a permanent property of the space. It holds only as long as the conditions and the planned work keep it true. This checklist supports the assessment work behind that conclusion: reviewing the planned activities, testing the atmosphere, checking for physical hazards, and recording what you found at each phase of the job. It does not cover entry requiring a permit, and it should not be used to justify entry where a serious hazard exists.

Why it matters

Work inside any confined space is less forgiving than work in the open. Ventilation may be poor, escape routes are limited, and a change in the atmosphere can affect an entrant before they can get out. A space that starts the day non permit-required can become hazardous through something as ordinary as bringing in a solvent, running an engine nearby, or disturbing loose material. The purpose of this assessment is to catch those changes before entry and to keep checking through the job. It asks you to confirm that planned work activities will not introduce new hazards, that nothing capable of generating toxic gases or harmful fumes will be brought in or used, and that conditions outside the space will not adversely affect the people inside it or working nearby. Where hazards are identified, the checklist gives you a place to record them and the corrective actions taken or recommended.

What a good assessment covers

A complete assessment looks at the space, the work and the atmosphere together. - **The work itself.** Every planned activity is reviewed to confirm it will not introduce a new hazard, and to confirm that no chemicals, solvents, adhesives or similar substances capable of producing toxic gases or harmful fumes are brought in or used. - **The surroundings.** External conditions, adjacent operations and environmental factors are checked for anything that could affect safety inside the space or in the area around it. - **The atmosphere.** Air monitoring equipment is checked for calibration and readiness, and readings are taken for oxygen, hydrogen sulfide, carbon monoxide and the lower explosive limit or lower flammable limit. Oxygen is judged against an acceptable range of 19.5% to 23.5%; readings below or above that range, or equipment not yet tested, are recorded as such. An overall atmospheric safety confidence rating closes the section. - **Physical hazards and materials.** Entrants are checked against engulfment materials such as water, grain, sand or other loose granular materials; mechanical equipment is checked for guarding, maintenance and injury risk; electrical conductors are checked for exposed, unguarded or stray wiring; fall hazards are identified and protection measures confirmed; and the space is checked for asbestos-containing materials or materials capable of generating asbestos fibers. - **The record.** Additional hazards, environmental concerns and observations are documented along with corrective actions, and the inspection is signed and dated with the actual start and end of the work.

How to carry it out

1. **Assess before entry.** Record the location or identifier and who prepared the assessment. Review each planned work activity and confirm it will not introduce new hazards. Confirm no hazardous chemicals, solvents or adhesives will be brought into or used within the space. Check external conditions and nearby operations for anything that could affect safety. Complete the physical hazard and material checks before anyone enters. 2. **Prepare the monitoring equipment.** Confirm the air monitoring equipment is calibrated and ready. A unit calibrated within the last 12 months, one that needs verification before use, one that needs recalibration, and one that is not available on site are different situations and should be recorded as they are. 3. **Test and record the atmosphere.** Take readings for oxygen, hydrogen sulfide, carbon monoxide and LEL/LFL, and record each against its status. Set an overall atmospheric safety confidence rating for the results as a whole. 4. **Continue monitoring during operations.** Conditions can change while work is under way. Keep checking so that a shift in gas levels or air quality is noticed and acted on rather than assumed away. 5. **Re-check as the job progresses and at completion.** Use the same checks at the end of the work as at the start, and record the finished time alongside the real start and end dates. 6. **Document what you found.** Record any additional physical hazards, environmental concerns or observations, and note the corrective actions taken or recommended. Sign the completed assessment. > If a hazardous atmosphere is detected, if engulfment or another serious hazard is present, or if planned work would introduce a new hazard, the space should not be treated as non permit-required. Stop and follow the applicable protective measures before anyone enters.

Frequently Asked Questions

A non permit-required confined space is a confined space that does not contain or have the potential to contain a hazardous atmosphere, a material that could engulf an entrant, an internal configuration that could trap or asphyxiate an entrant, or any other recognized serious safety or health hazard. This checklist defines the space in practice by testing it against those conditions: planned work activities are reviewed, air monitoring covers oxygen, hydrogen sulfide, carbon monoxide and LEL/LFL, and materials that could engulf an entrant or other physical hazards are checked.

Because the space no longer qualifies as non permit-required once a serious hazard exists. Planned work can bring in chemicals, solvents or adhesives that generate toxic gases or harmful fumes, introduce a hazardous atmosphere, or otherwise create a condition the space did not have before. Confirming in advance that activities do not introduce new hazards keeps the space in the non permit-required category and keeps entrants out of danger.

You assess the space before entry, during operations and upon completion. Air monitoring equipment is checked for calibration and readiness before testing begins, and gas readings are taken across the phases of work so that changes in the atmosphere are noticed. Documenting findings, additional hazards and any corrective actions, along with signatures and start and end dates, keeps a record of what was found and when.

Four hazards are typically assessed in the atmosphere: oxygen concentration, hydrogen sulfide, carbon monoxide, and the lower explosive limit or lower flammable limit. Oxygen is judged against an acceptable range of 19.5% to 23.5%, and equipment must be calibrated and operational before readings are relied upon. The checklist also records an overall atmospheric safety confidence rating to capture how the results are judged together.

The checklist looks for materials or substances that could engulf an entrant, including water, grain, sand and other loose granular materials; unguarded or poorly maintained mechanical equipment; exposed, unguarded or stray electrical conductors; fall hazards within and around the space; and asbestos-containing materials or materials capable of generating asbestos fibers. It also provides a place to record any additional physical hazards, environmental concerns or corrective actions identified.

No. Use this checklist only where all entry conditions are met and the space remains free of serious safety hazards. If a hazardous atmosphere is detected, if engulfment or other serious hazards are present, or if planned work would introduce new hazards, stop and follow the applicable protective measures. Document what was found and any recommended corrective actions so the condition can be addressed before entry.

Written by

Arne Reis

Founder

Process optimizer with 25 years of expertise, focused on operational excellence in quality, maintenance, EHS, and commissioning. Emphasizes innovative solutions and top-quality standards.

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