A breathing apparatus set can appear serviceable on a rack and still fail at the point of use. A damaged face seal, depleted cylinder, sticking demand valve or missed inspection can turn a critical control into a source of exposure. Knowing how to test breathing apparatus therefore means applying a documented routine before use, supported by competent periodic inspection and maintenance.

The precise method depends on the equipment type, manufacturer instructions, site risk assessment and applicable legislation. This guidance is intended for open-circuit self-contained breathing apparatus (SCBA) commonly used in firefighting, rescue, confined-space and hazardous-atmosphere work. Escape sets, airline systems, rebreathers and emergency escape breathing devices require their own approved procedures.

Start with the correct test regime

Breathing apparatus must not be treated as a single pre-use check followed by indefinite storage. A dependable regime separates user checks from scheduled functional testing, cleaning, inspection and specialist servicing. The intervals should be set by the manufacturer, the duty cycle, environmental conditions and the site’s respiratory protective equipment programme.

For example, a set used routinely in a marine engine room or offshore process area may require more frequent attention than one stored in a protected emergency cabinet. Salt-laden air, hydraulic oil, dust, high heat and UV exposure all accelerate deterioration. Equipment that has been dropped, exposed to contamination or used during an incident should be inspected before it is returned to operational readiness, regardless of the planned schedule.

Before testing, identify the set by its asset number and confirm that its service status is current. Check that the cylinder, facepiece, demand valve and harness are compatible components from the approved configuration. Interchanging apparently similar parts is not an acceptable substitute for manufacturer-approved equipment control.

How to test breathing apparatus before use

A pre-use inspection should take place in a clean, well-lit location. The wearer or designated competent person should work through the same sequence every time, recording defects immediately rather than relying on memory.

Inspect the cylinder and harness assembly

Begin with the cylinder valve closed. Check the cylinder body for dents, cuts, deep abrasion, heat damage, corrosion or evidence of chemical attack. Confirm that the cylinder is within its required inspection and test dates, that its label remains legible and that it is securely retained in the backplate.

Inspect the valve, handwheel, threads and protective cap where fitted. There must be no visible damage, contamination or signs of leakage. Check the pressure gauge lens and hose for damage, kinks or insecure fittings. The gauge must be readable in the working position.

Examine the backplate, shoulder straps, waist belt, buckles and adjustment points. Look particularly for fraying, cuts, melted sections, stiff webbing and broken stitching. The harness must tighten and release correctly, with no twisted straps that could affect fit or wearer comfort. Inspect pneumatic hoses for cracking, abrasion and insecure routing.

Check cylinder pressure and air availability

Open the cylinder valve slowly and fully, following the equipment manufacturer’s direction. Observe the pressure gauge or electronic display and compare the reading with the site’s minimum operational pressure. A cylinder that is not adequately charged must be removed from service and recharged through the approved process.

Do not assume that a cylinder is ready because it feels heavy or because a previous user reported it as full. Gauge readings, digital indicators and cylinder identification must be checked at the time of issue. Where the unit has a telemetry or heads-up display system, confirm that it powers up and provides the expected status indication.

After pressurising the set, allow the reading to stabilise. Monitor for pressure loss using the manufacturer’s specified leak-test period and acceptance criteria. A falling pressure reading may indicate a leak at the cylinder valve, pressure reducer, hose connection, gauge line or demand valve. Do not attempt improvised repairs to high-pressure components.

Test the warning device and demand valve

With the set pressurised, carry out the functional checks specified for the model. These commonly include confirming operation of the low-pressure warning whistle, alarm or electronic alert. Reduce pressure only in the controlled manner stated by the manufacturer. Do not deliberately exhaust a cylinder in an unsuitable area or compromise the availability of emergency equipment.

Check that the demand valve connects securely to the facepiece and that its controls, where fitted, move freely. Test normal breathing operation in accordance with the approved procedure. If the apparatus uses a positive-pressure demand valve, verify that it activates and resets as designed. Abnormal airflow, continuous free flow, delayed response or an irregular sound requires the set to be quarantined.

Inspect and fit-test the facepiece

The facepiece is a life-critical interface, not an accessory. Check the visor for scratches, cracks, clouding or distortion that could affect vision. Inspect the seal, harness, exhalation valve, speech diaphragm and inlet connection for tears, deformation, contamination or missing parts.

A clean, undamaged facepiece does not automatically provide protection. Each wearer must be fit-tested with the specific make, model and size of tight-fitting facepiece before being assigned to work requiring respiratory protection. Routine user seal checks are still necessary every time the facepiece is donned. Facial hair, eyewear incompatible with the seal, headwear and facial movement can all affect performance.

Follow the manufacturer’s method for the positive- or negative-pressure seal check. If a satisfactory seal cannot be achieved, the wearer must not enter the hazardous area using that tight-fitting apparatus. Consider an alternative approved facepiece size or respiratory protection arrangement through the site’s competent RPE process.

Periodic functional testing requires competent control

Pre-use checks are not a replacement for scheduled inspection by trained personnel. Periodic testing may require calibrated test equipment to measure leak rates, pressure performance, warning activation, airflow and facepiece valve function. These tests should be completed only by personnel trained and authorised for the equipment range in use.

Service intervals are not interchangeable between manufacturers. Use the operating manual and service documentation for the exact acceptance limits, replacement parts, lubricants and test method. A generic workshop procedure may overlook model-specific requirements, particularly on electronically monitored SCBA or equipment with integrated communications.

Cylinder inspection and requalification also require specialist control. Never modify, repaint without approval, heat, drill or attempt to repair a compressed-air cylinder. Damaged or out-of-date cylinders should be isolated and referred to an authorised cylinder testing or service provider.

Record results so defects can be acted on

A test is only useful if the result is traceable. Maintain a record for each set showing the asset number, cylinder identification, date, test performed, outcome, defects found, corrective action and the name of the competent person. Digital asset systems can improve visibility across shifts, vessels and project locations, but a simple controlled register is preferable to an incomplete system.

Defective apparatus must be clearly marked, physically separated from serviceable equipment and reported through the site’s maintenance process. Do not leave a failed set in an appliance locker, emergency cabinet or BA control area with the expectation that the next user will notice the problem.

For multi-site operations, standardising inspection labels, quarantine tags and handover records helps prevent equipment from being transferred between locations without a clear service history. This is particularly valuable where marine, offshore and shutdown teams share pooled emergency equipment.

Protect equipment between tests

Correct storage preserves the results of a satisfactory test. Store breathing apparatus clean, dry and protected from direct sunlight, extreme temperatures, chemicals and physical impact. Keep facepieces protected from distortion and contamination. Cylinders should be secured against movement during storage and transport.

After operational use, decontaminate the equipment using the manufacturer-approved process before inspection or reuse. Fire residues, hydrocarbons and biological contaminants can present a risk to the next wearer and may degrade seals, valves and harness materials. Where exposure is uncertain, treat the set as contaminated until assessed by a competent person.

SFRM supports industrial teams with safety and rescue equipment supply aligned to operational requirements, including the technical coordination needed for critical equipment programmes. The most effective approach combines correctly specified apparatus, trained users, controlled maintenance and reliable access to approved spares.

When a breathing apparatus set fails a check, the decision is straightforward: remove it from service. Maintaining availability matters, but it never justifies issuing equipment whose performance cannot be verified before a worker enters a hazardous atmosphere.