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Breathing-apparatus exercise of the Bosch plant fire brigade in a smoke-filled building. Stuttgart, Germany, 2018.

Working where the air is the hazard

An independent reference on gas rescue, mine rescue and breathing-apparatus work — equipment, gas hazards, standards, training and lessons from real incidents.

Gas hazardsStandards

Breathing-apparatus exercise of the Bosch plant fire brigade in a smoke-filled building. Stuttgart, Germany, 2018. · Photo: Funki87 · CC BY-SA 4.0 · Source: Wikimedia Commons

Sections

ProfessionWho gas rescuers are, where they work and how teams are organisedTasksRescue, reconnaissance, isolation and standby at hazardous workEquipmentBreathing apparatus, gas detectors, protective clothing and rescue gearSafetyThe core rules for work in hazardous atmospheresGas hazardsToxic, asphyxiant and flammable gases: densities, explosive limits, IDLHStandardsEN, ISO, NFPA, OSHA, ГОСТ and DGUV documents with current status and scopeTrainingSelection, medical fitness, initial training, drills and competitionsCase studiesReal accidents from official investigation reports and what rescuers can learn from them.HistoryFrom the first oxygen apparatus to modern SCBA and organised rescue servicesGlossaryKey terms of gas rescue work explainedOrganisationsInternational bodies, regulators and rescue services with official linksFAQShort answers to the questions people ask most often about gas rescue.

Key facts

  • 100 ppm hydrogen sulfide is classed by NIOSH as immediately dangerous to life or health (IDLH). NIOSH
  • 19.5 % oxygen: below this, OSHA treats the atmosphere as oxygen-deficient; normal air holds 20.9 %. OSHA
  • >60 % of confined-space fatalities studied by NIOSH were would-be rescuers. NIOSH
  • 1200 ppm carbon monoxide is the NIOSH IDLH value — and the gas has no smell or colour. NIOSH

Gas hazards at a glance

GasMain hazardKey figure
Hydrogen sulfide (H2S)Toxic and flammable; deadens the sense of smellIDLH 100 ppm
Carbon monoxide (CO)Toxic, no smell or colour; flammableIDLH 1200 ppm
Methane (CH4)Flammable; displaces oxygen; lighter than airLEL 4.4 % (IEC), 5 % (US)
Carbon dioxide (CO2)Asphyxiant; collects in low placesIDLH 40 000 ppm
Oxygen deficiencyNo warning signs before collapsebelow 19.5 % O2

Full table with explosive limits and exposure limits by country: Gas hazards.

Latest articles

Communication in breathing apparatus teamsHow BA teams stay in contact — radio discipline, Ex-rated radios, voice amplifiers, line and hand signals, entry control, distress signals and telemetry.Heat stress in protective clothingWhy protective clothing and breathing apparatus cause heat strain, how to plan work and rest, hydrate, cool down and recognise heat illness early.Common mistakes with self-contained breathing apparatusTypical errors with self-contained breathing apparatus — skipped checks, poor mask seal, air management, entry control — and how to avoid them.Oxygen deficiencyWhy oxygen-deficient atmospheres kill without warning: inert gases, effects on the body, purging, oxygen monitoring, limits in different countries and why rescuers die.

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