Confined Space Entry
permit to work

Entry into any enclosed or substantially enclosed space with risk of injury from hazardous substances or conditions.

These are the precautions the issuer confirms before signing. Each one says what good looks like, when it passes, the regulation it rests on and how it usually fails. Critical precautions are marked: if one cannot be confirmed, the permit is not issued.

Precautions before issue

1. 1.

   Confined space risk assessment completed

   Critical: a fail stops the work
   What to look forWritten, space-specific risk assessment (not generic) covering the five reasonably-foreseeable specified risks under reg 1(2): serious injury from fire/explosion, loss of consciousness from gas/fume/vapour, loss of consciousness from increased body temperature, loss of consciousness from oxygen deficiency, drowning, asphyxiation from a free-flowing solid. Assessment names the space, the task, the residual contents history (what last lived in this space, sludge, sewage, hydrocarbon residue, inert gas), the access dimensions, and entry duration.
   Acceptable whenReg 4 hierarchy followed: (a) avoid entry if possible (work from outside, robotic survey, CCTV); (b) if entry essential, safe system of work; (c) emergency arrangements before entry. Assessment signed by a competent person. Reviewed each shift, not just at first entry.
   StandardConfined Spaces Regulations 1997 reg 3, 4. HSE L101 Safe work in confined spaces (3rd ed 2014). HSE INDG258 Safe work in confined spaces. INDG163 Five steps to risk assessment.
   Common defectsGeneric "confined space" RA used for every space, actual residual contents not consideredReg 4 hierarchy skipped, entry approved without first asking "can this be avoided?"No emergency arrangements section, rescue plan deferred to "we will sort it"Free-flowing solid risk (silos, grain) not assessed, assumed only gas/oxygen risks applyAssessment 12+ months old, not reviewed despite changes to space contents
2. 2.

   Safe system of work established and briefed
   What to look forA written method statement specific to the space and task, briefed to all entrants and attendants pre-shift with a signed register. Covers entry sequence, who-does-what, gas-test timing, hot work prohibition, ventilation regime, communication signals, and the trigger conditions to abort entry. Briefing is interactive, entrants can articulate their escape route and emergency procedure back to the issuer.
   Acceptable whenMethod statement signed by all entrants. Entrants can demonstrate (verbally or by walk-through) the entry sequence, abort triggers, and rescue arrangements. Briefing within 24 hours of entry, not days old. Tool-box talk record retained.
   StandardConfined Spaces Regs 1997 reg 4(2)(b). HSE L101 ch.4. CDM 2015 reg 8 (cooperation, coordination).
   Common defectsVerbal briefing only, no signed record, content disputed after incidentGeneric RAMS lifted from a previous job, not space-specificEntrant cannot articulate the abort triggers when askedNew entrant joins mid-shift, not briefedMethod statement does not specify who calls the abort, multiple entrants assume someone else will
3. 3.

   Atmosphere tested, O2, LEL, CO, H2S

   Critical: a fail stops the work
   What to look forCalibrated 4-gas monitor (typical: bump-tested same shift, calibration cert in date). Pre-entry test taken from the bottom of the space, mid-level, and head-height using a sampling pump and probe, NOT just at the entrance, because heavier-than-air gases (H2S, CO2, propane) pool at the base. Readings recorded on the permit by reading. Test repeated continuously while occupied OR at minimum 30-min intervals for short tasks.
   Acceptable whenO2 between 19.5% and 23.5% v/v. LEL <10% (entry refused at >10%). CO <30 ppm 8-hr TWA, 200 ppm STEL (HSE EH40/2005). H2S <5 ppm 8-hr TWA, 10 ppm STEL. Substance-specific WEL where the space history demands (e.g. methane in sewers, benzene in fuel tanks, NO2 in road tunnels). Where flammable atmosphere is possible the monitor must be intrinsically safe (ATEX certified).
   StandardConfined Spaces Regs 1997. HSE L101, Safe work in confined spaces. HSE INDG258. EH40/2005 Workplace exposure limits. ATEX 2016/0352 / DSEAR 2002 (intrinsic safety). BS EN 60079 series.
   Common defectsSingle-point test at entrance only, toxic gas pooled at base undetectedBump test or calibration overdue, readings unreliableNo continuous monitoring during entry, atmosphere can change without warningNon-IS monitor used in flammable space, ignition sourcePre-entry test taken before forced ventilation has had time to work, false negativeSubstance-specific WEL not checked, only the four standard gases testedPermit issued before atmosphere proven safe
4. 4.

   Continuous gas monitoring in place
   What to look forPersonal 4-gas monitor worn on the entrant in the breathing zone (lapel/collar height), not clipped to a belt where readings reflect waist-level air. Audible and visual alarms set to factory defaults (not silenced or de-sensitised). Monitor logs readings to memory for download. Where multiple entrants, each has their own monitor. Datalogged readings retrieved post-shift and retained for 5 years (occupational exposure record).
   Acceptable whenMonitor in breathing zone. Alarms enabled (not muted). Datalog reviewed at end of shift. Calibration cert valid (typical 6-month full cal, daily/shift bump test). Alarm thresholds: O2 low 19.5%, O2 high 23.5%, LEL 10%, CO 30 ppm, H2S 5 ppm.
   StandardCOSHH 2002 reg 10 (monitoring exposure). EH40/2005. HSE L101. BS EN 60079-29-1 (gas detector performance).
   Common defectsMonitor on belt, reading 30cm below face, missing breathing-zone exposureAlarms muted because they "kept beeping" near contaminated entryDatalogger never downloaded, exposure history lostSingle shared monitor between two entrants, only one position coveredBump test skipped, sensor failure undetected until alarm fails to trigger in incident
5. 5.

   Ventilation provided (natural or forced)
   What to look forForced ventilation (electric fan + ducting) running for a defined pre-purge period before entry, typically 5-10 air changes prior to first entry. Ducting reaches the bottom of the space, not just the entrance. Where the space is large or layout complex, both supply and extract fans used. Air drawn from a clean source (not next to a vehicle exhaust, generator outlet, or sewer vent). Ventilation runs continuously throughout occupation.
   Acceptable whenMinimum 5 air changes before first entry. Continuous ventilation throughout occupation. Air supply from clean source >5m from any contaminant or exhaust. Ducting reaches the working level. Re-test atmosphere after ventilation pre-purge to confirm effectiveness.
   StandardHSE L101 ch.5. INDG258. COSHH 2002 reg 7 (control). DSEAR 2002 (where flammable).
   Common defectsDucting hangs at entry point, bottom of space unventilated, gas pocket persistsFan supply from beside generator exhaust, CO drawn into supposed clean-air supplyNo pre-purge period, entry made within 30 seconds of fan start, before atmosphere clearsSingle fan in a large space, short-circuiting of air flow, dead zonesFan switched off because it was "too noisy", atmosphere degrades unmonitored
6. 6.

   Rescue plan in place and rescue team on standby

   Critical: a fail stops the work
   What to look forA written rescue plan that does NOT rely on the fire and rescue service alone, the law requires rescue arrangements that work without external help (Reg 5). Rescue equipment matches the casualty extraction route (vertical = tripod and winch with mechanical advantage; horizontal = stretcher and dragline). Rescue team is competent, drilled within last 6 months, with breathing apparatus appropriate to the space (SCBA for IDLH, escape sets for limited duration). Local fire and rescue service notified IF the plan relies on supplementary capability.
   Acceptable whenReg 5 self-rescue capability. Rescue team trained to BS 8454 / IRATA / equivalent. SCBA where atmosphere may be IDLH. Drilled within last 6 months for this site or similar geometry. Recovery time from collapse to fresh air <4 minutes for unconscious casualty (brain hypoxia threshold).
   StandardConfined Spaces Regs 1997 reg 5. HSE L101 ch.6. BS 8454:2006 delivery of training for work at height and rescue from height. RIDDOR 2013 (reportable incident on failure).
   Common defectsRescue plan = "phone 999", non-compliant with reg 5 (4-min hypoxia window vs 8-min FRS response)Rescue team has the right gear but no drill within last 12 months, slow executionTripod rated for 1-person but casualty is 95kg + 15kg gear + harness leverage = >135kgNo SCBA on standby, rescuers cannot enter if atmosphere has degradedRescue team also doing the work, no-one independent on standby
7. 7.

   Rescue equipment available (tripod, winch, harness)
   What to look forTripod (or quadpod) over the entry with full body harness on entrant connected via a man-rated retrieval winch (NOT a materials winch) and shock-absorbing fall arrest lanyard. Tripod legs spread to manufacturer specification with anti-slip feet on solid ground. Winch cable runs free with no kinks. All kit LOLER inspected within 6 months and tagged.
   Acceptable whenTripod and winch certified to EN 795 class B and EN 1496 class B (rescue winch). Harness EN 361. Both LOLER inspected within 6 months (every 6 months for kit subject to wear, every 12 for static). Cable free, harness chest D-ring used for vertical retrieval (not waist).
   StandardLOLER 1998 reg 9. Work at Height Regs 2005. EN 795 anchor devices. EN 1496 rescue lifting devices. EN 361 full-body harnesses.
   Common defectsMaterials winch (not man-rated) used for retrieval, uncontrolled descent on failureTripod feet on loose gravel, leg slips during a loadHarness clipped to waist D-ring instead of chest, casualty inverts during retrievalLOLER tag absent or expiredKit shared between multiple entries, second entry made without re-rigging
8. 8.

   Communication system between entrant and attendant
   What to look forVoice contact maintained continuously, line-of-sight where possible, hard-wired comms or radio where not. Pre-agreed signals for "I am OK", "trouble, coming out", "evacuate, get rescue". Radio tested in-position before entry (steel tanks attenuate UHF, VHF or hard-wired may be needed). Where radio fails, entrant exits.
   Acceptable whenContinuous two-way voice contact throughout occupation. Pre-tested in the actual space (not just on the surface). Pre-agreed signal vocabulary briefed and signed off. Lifeline tugs as a tertiary backup (1 = OK, 2 = come, 3 = trouble, 4 = pull me out).
   StandardHSE L101 ch.4. INDG258. Confined Spaces Regs 1997 reg 4(2)(b).
   Common defectsUHF radio in steel tank, signal blocks within 2m of opening, entrant out of commsNo pre-agreed signal vocabulary, attendant uncertain whether shout is "OK" or "help"Single radio shared between two entrants, second entrant uncontactableComms test done at the surface only, not inside, failure discovered during incidentLifeline tug code not briefed, backup unusable
9. 9.

   Lighting adequate (intrinsically safe if required)
   What to look forTask-area illuminance suitable for the work being done, typically 300-500 lux for inspection/maintenance, 750+ lux for fine welding/electrical work. Lighting is intrinsically safe (ATEX zone 1 or zone 2 rated) where flammable atmosphere is possible. 110V CTE lighting where mains is needed (reduced shock risk in damp confined space). Battery/LED head torches as secondary.
   Acceptable whenIlluminance 300-500 lux task area. ATEX-certified lighting (IIC T4 or better) where DSEAR risk. 110V CTE for mains-powered. Cables protected from abrasion at the entry point.
   StandardWorkplace (Health, Safety and Welfare) Regs 1992 reg 8 (lighting). DSEAR 2002. BS EN 60079 series. EN 1838 emergency lighting.
   Common defects230V mains lighting in a damp tank, shock risk + non-ISStandard LED torch in zone 1 atmosphere, potential ignition sourceCable insulation chafed at sharp manhole edge, entrant relies on intact insulation in wet conditionsSingle light source, shadow blocks task viewNo backup torch on entrant, primary fails, entrant in dark
10. 10.

    Emergency services notified (if required)
    What to look forWhere the rescue plan relies on the fire and rescue service for any element (e.g. extended BA capability, road traffic management for casualty extraction), the local FRS technical rescue team is notified before entry, typically by phone to the watch commander, with site address, what3words location, access route, expected occupancy hours, casualty profile, and contents of the space. NOT a substitute for in-house Reg 5 capability.
    Acceptable whenNotification logged with FRS name and timestamp. What3words or grid reference provided. Access for fire appliance confirmed. Site has a dedicated banksman to receive emergency services if called.
    StandardFire and Rescue Services Act 2004 s.6 (response). HSE L101. Reg 5 still applies, FRS is supplementary not primary.
    Common defectsFRS notified but reg 5 self-rescue not arranged, entry illegal regardlessNotification sent to wrong station, local appliance not the technical rescue stationSite access blocked by site security barrier without out-of-hours codeNo banksman to meet appliance, 5-minute delay finding the entry point
11. 11.

    Entrant trained and competent

    Critical: a fail stops the work
    What to look forDocumented training valid for the space classification: low-risk (City and Guilds 6160-01 or equivalent), medium-risk (6160-02), high-risk (6160-03). Refresher within last 3 years. Entrant has demonstrated competence with the specific equipment to be used (escape set, BA, gas monitor). Medical fitness, no claustrophobia, cardiac, or respiratory issues precluding entry.
    Acceptable whenTraining certificate appropriate to the space classification. Refresher <3 years old. Medical fitness declaration. First-time entrant under direct supervision of an experienced colleague.
    StandardHSE L101 ch.4. C&G 6160 confined space training framework. Health and Safety at Work Act 1974 s.2 (information, instruction, training).
    Common defectsLow-risk-trained entrant in medium-risk space (escape set required), undertrainedRefresher 5+ years old, competency assumed not verifiedNo medical fitness declaration, entrant suffers panic attack in spaceFirst-time entrant unsupervisedTraining was generic e-learning, no practical drill
12. 12.

    Top person/attendant appointed and will not leave
    What to look forA dedicated attendant whose only job is to attend, not the issuer, not also driving the LEV fan, not on the phone. Sits at the entry point with permit, gas readings, comms, retrieval winch handle, and the abort signal authority. Cannot be relieved without a formal handover signed on the permit. Abandoning the post is a sackable offence (and a Confined Spaces Regs reg 5 breach that has prosecuted to 6-figure fines).
    Acceptable whenSingle named attendant at the entry for the whole occupation. Handover only with formal sign-on/sign-off. Attendant has retrieval winch within reach, comms in hand, and authority to abort entry without referral.
    StandardConfined Spaces Regs 1997 reg 5. HSE L101 ch.4. INDG258.
    Common defectsAttendant doubles up as banksman for a delivery, leaves entry to direct lorryAttendant takes a comfort break with no formal handover, entry unattended for 8 minutesPhone call distracts attendant, does not hear abort shoutAttendant has no authority to abort, refers to issuer, who is off-siteTwo entrants, one attendant cannot watch both retrieval lines simultaneously

Questions people ask