What this is
What is an atmospheric test record?
What is an atmospheric test record?
It is the log of gas readings, oxygen, flammables and named toxics, taken before a confined space entry begins and repeated through the entry, against a calibrated instrument. It is the evidence that the atmosphere was acceptable at the moment entry was authorised and stayed acceptable while people were inside.
Why is a single pre-entry reading not sufficient?
An atmosphere inside a confined space is not static. Residue continues to off-gas, hot work generates fumes, ventilation equipment can fail, and gases stratify by density so a reading at one height can miss a layer entirely. A record built on one reading describes a moment that may already be out of date by the time the first person enters.
Who is qualified to take the test?
A person trained on the specific instrument and the testing sequence, not simply someone handed a meter. Training covers reading the display correctly, recognising when the instrument itself is faulted or unpurged, and knowing what to do, principally stopping entry, when a reading falls outside limits.
Scope
When is an atmospheric test record required?
This record is one step in the confined space entry sequence, tied to a specific permit and a specific space. Using it to justify a classification decision, rather than to gate a single entry, mixes two different pieces of evidence.
Use this template when
- A confined space entry is about to begin and the pre-entry atmospheric test is due
- An entry is already under way and the retest interval has been reached
- Work inside the space, hot work, cleaning, application of coatings, could plausibly change the atmosphere
- A reading is required at a different test point because the space geometry allows stratification
- An unexpected reading needs to be investigated even though no one was harmed
Do not use it for
- Confined Space Register, which lists every confined space on site, its hazards, its classification and its entry requirements, rather than a single test.
- Entry Attendant Log, which records who is in the space, when they entered, when they left and every communication check, not the atmosphere itself.
- Confined Space Rescue Drill Record, which records a practice rescue and time to recover a casualty, not a live gas reading.
- Confined Space Reclassification Review, which uses a pattern of atmospheric test records as evidence for a classification decision, but is a separate decision from any one test.
- Anything outside KnowSafe, which belongs in the workspace that owns that process
Compliance mapping
Which OSHA 1910.146(c)(5) requirements does this satisfy?
OSHA 1910.146 is specific about testing atmosphere, more so than about almost anything else in the standard, because the atmospheric hazard is the one most likely to be invisible until someone is already affected by it.
| Clause | Requirement | Where it lands |
|---|---|---|
| OSHA 1910.146(c)(5) | Test or monitor the space as necessary to determine that acceptable entry conditions are maintained during the course of entry | Readings |
| OSHA 1910.146(c)(5) | Test the atmosphere in sequence: oxygen, then combustible gases and vapours, then toxic gases and vapours | Readings |
| OSHA 1910.146(c)(5) | Testing instruments must be calibrated and maintained in accordance with the manufacturer's specification | Instrument |
| OSHA 1910.146(d) | The permit space programme identifies each space's hazards and the means by which they are tested for | Header |
| OSHA 1910.146(e) | Acceptable entry conditions, including atmospheric conditions, must exist before entry is authorised under the permit | Outcome |
| OSHA 1910.146(k) | Rescue and emergency arrangements depend on continuous monitoring where the atmosphere is capable of changing during entry | Outcome |
What it does not cover
- Confined Space Register, which lists every confined space on site, its hazards, its classification and its entry requirements.
- Entry Attendant Log, which records who is in the space, when they entered, when they left and every communication check.
- Confined Space Rescue Drill Record, which records a practice rescue from a confined space, including time to reach and recover the casualty.
- Confined Space Reclassification Review, which decides whether the space's standing hazard classification should change, using a pattern of tests as part of its evidence.
- Confined Space Entry Permit, which authorises the entry as a whole and references this test as one of its conditions, rather than substituting for it.
Global
Atmospheric Test Record requirements by country
Testing before and during confined space entry is expected almost everywhere hazardous atmospheres are regulated; what varies is how prescriptive the sequence and the recorded evidence must be.
OSHA 1910.146(c)(5)
Testing in a defined sequence, oxygen then combustibles then toxics, with periodic or continuous monitoring while entry continues.
The sequence and the record of each test point are themselves inspectable; an incomplete sequence or a missing retest is a citable gap independent of the outcome.
Confined Spaces Regulations 1997 and HSE guidance (L101)
A suitable and sufficient assessment of the atmosphere is required before entry, with testing method left to the duty holder's competent judgement.
There is no codified testing order, but a duty holder unable to show a defensible testing method and interval faces the same practical exposure as a missed OSHA requirement.
Occupational exposure limits set nationally, no single confined space testing standard
Acceptable readings are benchmarked against national occupational exposure limits for oxygen, flammables and named toxics, applied within whatever local confined space regulation exists.
A multinational operator testing to one internal standard still needs to confirm its limits are at least as strict as the local exposure limits in force at each site.
How to complete it
How to complete an atmospheric test record, step by step
The template captures numbers against limits. What makes the record trustworthy is what happened around those numbers.
The test point field exists because gases stratify: a heavier-than-air gas can pool at the bottom of a space while a reading taken at the collar shows nothing unusual. A record with every reading logged at one point has not tested the space, it has tested one location in it.
The retest interval is where most atmospheric incidents actually live, because the pre-entry test is the one everyone remembers to do. A record with a clean pre-entry reading and no subsequent readings during a long entry has documented the easy half of the requirement.
Calibration, bump test and sample line purge are not paperwork ahead of the real test; an uncalibrated or unpurged instrument produces a number that looks exactly like a valid one. A pass recorded on a meter that failed its bump test is not a pass, it is an unverified guess.
An atmosphere outside limits that stopped an entry before anyone was exposed is still worth a case record, because the same unexplained cause is likely to recur on the next attempt. Closing the record with 'entry not permitted' and no further action leaves the underlying cause for someone else to discover the hard way.
What auditors find
Most common atmospheric test record findings
Because the test itself is quick and mechanical, most findings concern what surrounds it: how many times it was done, at how many points, and on what evidence the instrument was trusted.
| Finding | Clause | What fixes it |
|---|---|---|
| Only a pre-entry reading recorded, with no retest during a prolonged entry. | OSHA 1910.146(c)(5) | Set and enforce a retest interval appropriate to the space and the work, and record every retest. |
| Readings taken at a single test point despite a space capable of stratification. | OSHA 1910.146(c)(5) | Require readings at top, middle and bottom, or at the work position, whichever the space geometry demands. |
| Gas detector used without a same-day bump test or with calibration overdue. | OSHA 1910.146(c)(5) | Block the test record from being logged as complete unless calibration and bump test are both confirmed. |
| Entry permitted despite one or more readings outside limits, with no recorded action. | OSHA 1910.146(e) | Tie entry authorisation directly to the all-within-limits result, and require an action note whenever it is No. |
| Continuous monitoring not left in place for a space with a history of changing atmosphere. | OSHA 1910.146(k) | Make continuous monitoring the default for any space with a prior out-of-limits reading, not an optional extra. |
| Unexpected out-of-limits reading closed with no case record, because nobody was hurt. | OSHA 1910.146(c)(5) | Raise a case for any reading outside limits regardless of outcome, and route it to investigation. |
Case in point
Case in point: the fan that failed quietly
A tank entry began with a clean pre-entry test: normal oxygen, no measurable flammables, no detectable toxics. The permit was signed, continuous monitoring was marked not applicable because the space had never previously shown a problem, and the crew went in for a coating job expected to take three hours.
An hour in, the portable extraction fan supplying the space lost power at a junction box outside, unnoticed because nobody was watching the fan itself. Fumes from the coating accumulated with no ventilation and no retest scheduled until the two-hour mark. The worker inside became disoriented before the scheduled retest was due, and was pulled out by the attendant on a communication check that happened to fall early. The retest interval on record had been set to match the coating manufacturer's general guidance, not the specific ventilation arrangement actually in use for that tank.
The template
The template, field by field
The form exactly as it installs. Every field, option, score and conditional rule is editable, and the links to other templates come with it.
4 sections
- Reference
- SAF-106
- Archetype
- Record
- Record ID
- ATM-2026-000
- Scoring
- Pass or fail
- Direction
- High is good
- Singleton
- No
- Basis
- OSHA 1910.146(c)(5)
- Links
- Links Permit, Space
- Tags
- Confined space, Monitoring
- Sections
- 4
- Fields
- 34
- Follow up fields
- 2
- Repeating sections
- 1
- Links out
- 4
Header
9 fieldsTest ID*
Auto sequence. Format ATM-2026-0000.
The record's own ID. Other templates point at this value.
Status*
Drives who this goes to next.
- Planned2 pts
- In progress2 pts
- Complete3 pts
- Deferred0 pts
- Open0 pts
- Closed3 pts
- Overdue0 pts
Date and Time*
Completed By*
Site*
Site ID*
Format SITE-000.
Links to FDN-001 Site ID
Permit ID*
Links to SAF-049 Permit ID
Space ID*
Links to SAF-105 Space ID
Test Before, Test During
Atmosphere changes. Residue continues to off gas, work generates fumes, and ventilation fails. A single test before entry is not enough.
Instrument
7 fieldsGas Detector*
Asset ID*
Format AST-0000.
Links to FDN-002 Asset ID
Calibration Current*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Bump Test Passed Today*
- Pass2 pts
- Partial1 pt
- Fail0 pts
- N/Aexcluded from denominator
Sample Line Purged*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Tested By*
Tester Trained*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Readings
Repeats10 fieldsReading Time*
Test Point*
Top, middle and bottom. Gases stratify and a single point misses layers.
Oxygen Percent*
Flammable Percent LEL*
Carbon Monoxide PPM
Hydrogen Sulphide PPM
Carbon Dioxide PPM
Ammonia PPM
All Within Limits*
- Yes3 pts
- No0 pts
Action Taken If Out Of Limits
Outcome
8 fieldsEntry Permitted*
- Yes3 pts
- No0 pts
Continuous Monitoring Left In Place*
- Yes2 pts
- No0 pts
- N/Aexcluded from denominator
Retest Interval Minutes*
Case ID
An unexpected atmosphere is worth investigating even though nobody was hurt.
Thread key
Tested By*
Signature*
Entry Supervisor*
Second Signature*
SAF-106 · record IDs look like ATM-2026-000 · Links Permit, Space
Open in KnowellaRun it with agents
From a document you fill in to a programme that runs itself
The test itself takes minutes. What fails around it is whether the retest happens on schedule, whether the instrument's credentials are current, and whether an unexplained reading gets followed up.
Ties each atmospheric test to its permit and space, blocks entry authorisation on an out-of-limits result, and prompts the next retest against the interval on file.
Tracks the gas detector's calibration and service history as an asset, so a test cannot be logged against an instrument whose calibration has lapsed.
Confirms the tester's competency record before a test is accepted, so the person taking the reading is verified as trained on that instrument.
Watches for a retest interval running late during a live entry and for unexplained out-of-limits readings that never generated a case, and raises both rather than waiting for a report to surface them.
This template lives in KnowSafe — safety and compliance. Incidents, hazards, permits, inspections and the critical controls behind them.
Meet KnowSafe→Glossary
Atmospheric Test Record definitions and key terms
- LEL
- Lower explosive limit: the minimum concentration of a flammable gas or vapour in air capable of igniting, expressed as a percentage the meter reads directly.
- Stratification
- The tendency of gases to settle or rise within a space according to density, which is why a reading at one height can miss a hazard present at another.
- Bump test
- A quick functional check that exposes a gas detector to a known concentration to confirm it responds and alarms correctly, distinct from full calibration.
- Acceptable entry conditions
- The set of atmospheric and physical conditions, including oxygen, flammable and toxic gas levels, that must exist before entry is authorised under the permit.
- Continuous monitoring
- A gas detector left running and sampling throughout an entry, rather than a single test repeated at intervals, used where the atmosphere is prone to change quickly.
FAQ
Frequently asked questions about atmospheric test record
Why must oxygen be tested before flammables and toxics?+
Because a low-oxygen reading changes how a subsequent flammable reading should be interpreted, and combustible sensors on many instruments are themselves oxygen-dependent. Testing out of sequence risks a flammable reading that looks acceptable but is being measured against an atmosphere the instrument was not designed to read accurately.
How many test points are enough?+
As many as the space's geometry requires to catch stratification: typically top, middle and bottom for a vertical space, or the actual work position for one without clear vertical layering. A single point is enough only for a space with no plausible layering, and that judgement should be documented, not assumed.
What counts as evidence the instrument was working?+
A same-day bump test that passed, current calibration, and a purged sample line if the instrument uses one. A reading from an instrument that has not cleared all three is not a reading that can be relied on, regardless of what number it shows.
What should happen when a reading is outside limits?+
Entry stops, or does not begin, and the action taken is recorded, not just the fact of the failure. Ventilating further, retesting, or abandoning the entry are all legitimate responses, but the record should show which one happened and what the following reading showed.
Does an unexpected reading need investigating if entry never happened?+
Yes. An atmosphere that failed a pre-entry test and stopped the job is still an unexplained event, and the same cause, a leaking line, a failed extraction system, a residue nobody accounted for, is likely to produce the same reading on the next attempt unless it is found and corrected.
How does the retest interval get set?+
Against the specific conditions of the entry: the work being done, the ventilation arrangement actually in place, and the space's history of any prior atmospheric issue. A generic interval taken from a product data sheet, rather than the entry as planned, is the interval most likely to be wrong when it matters.
Keep going
Related templates and programmes
Industries this is written for
Programmes this belongs to
Used together in Permit to Work
Contractor Permit Compliance Check
Checks that a contractor working under permit is doing what the permit says, at the work point
Hot Work Permit
Controls welding, cutting, grinding and any work that makes sparks or heat
Confined Space Entry Permit
Controls entry into tanks, pits, silos and other confined spaces
Energy Isolation Permit
Controls work where machinery must be shut down and locked out
Working at Height Permit
Controls work above the height set by local rules where fall protection is needed
Excavation Permit
Controls digging and trenching, including checks for buried services
More in Confined Spaces
Confined Space Register
Lists every confined space on site, its hazards, its classification and its entry requirements
Entry Attendant Log
Records who is in the space, when they entered, when they left and every communication check
Confined Space Rescue Drill Record
Records a practice rescue from a confined space, including time to reach and recover the casualty
Confined Space Reclassification Review
Reviews whether a space can safely be moved to a lower classification, or must be moved up
Written and reviewed by
Siddarth Singh
Founder & Chief Executive Officer, Knowella
Certified Safety Professional and industrial and systems engineer with more than a decade inside food supply chain, freight and manufacturing operations. This page was written against the current text of the standards it cites, not against secondary summaries of them.
- Certified Safety Professional (CSP), Board of Certified Safety Professionals
- MBA, University of Chicago Booth School of Business
- MS and BS, The Ohio State University, Industrial and Systems Engineering
- Six Sigma Black Belt
Sources and last review. Reviewed 16 August 2026 against:
- OSHA 1910.146(c)(5) — Testing and monitoring of permit space atmospheres
- OSHA 1910.146(d), (e) and (k) — Permit space programme, permit system and rescue
- Confined Spaces Regulations 1997 (UK) and HSE guidance L101
- ANSI/ASSP Z117.1 — Safety Requirements for Confined Spaces
This page is general guidance, not legal advice. Confirm requirements with your jurisdiction’s regulator.