Medical & Healthcare

Healthcare gas detection covers three different jobs that happen to use the same instruments. Protecting staff from gases the building uses. Protecting patients from gases delivered incorrectly. And in one case, protecting embryos from contamination measured in parts per billion.

Most of what follows comes from work our Technical Consultants have done in Australian hospitals and clinical facilities.

MRI Rooms, And Why The Detector Cannot Go In The Room

This is the most constrained detection problem in healthcare and the answer is unusual.

MRI machines use liquid helium to cool the superconducting magnets that produce the magnetic field. Each high field machine carries an inner dewar filled with helium and an outer dewar filled with liquid nitrogen. A leak of either displaces oxygen, and in a shielded room with a patient inside it, that is a serious hazard. Compliance requires MRI rooms to be fitted with an oxygen monitoring and alarm system.

The problem is that the magnetic field rules out putting the equipment in the room. All metal and electronics have to sit outside the room shielding.

So the system is built around sample draw. The sensor and the sample pump are installed outside the shielding, and a plastic sample line with end of line filters runs through a gland entry point into the room. Air is drawn out to the detector rather than the detector being taken to the air.

Several practical points follow. Sample lines should be PTFE (Teflon) lined. End of line filters limit particle ingress and need to be maintained. And the lines themselves need regular checking for blockage, because a blocked sample line is a monitoring system that reports nothing while appearing to work.

An additional audible and visual alarm should be installed above the MRI room entry, so anyone about to walk in is warned before they do. The VDP 2 sample pump draws the sample, a fixed oxygen detector ranged to 25 percent by volume does the measuring, and the SON4 sounder beacon provides the alarm at the door.

Ethylene Oxide Sterilisation

Ethylene oxide sterilisation is a low temperature method used for medical devices that heat and moisture would damage, and it is effective against bacteria, viruses and spores. It is also used in hospital laundry areas, which is where the detection challenge sits.

Ethylene oxide is a human carcinogen. Exposure causes respiratory problems and neurological effects, and residual gas has to be removed from sterilised items through proper aeration rather than assumed to have dissipated. Use and emission are strictly regulated.

Until 30 November 2026, the workplace exposure standard for ethylene oxide is an eight hour TWA of 1 ppm. From 1 December 2026, it has no limit at all under the new Workplace Exposure Limits, because there’s no known safe level, so exposure must be eliminated or minimised. Either way, it’s a very low threshold to alarm against, and a good reason for a dedicated sensor rather than a general purpose one.

Laundry rooms add high humidity from steam and elevated temperatures, which is a harder environment than a sterilisation suite. A D-Guard²S with an ethylene oxide sensor and integral sounder strobe suits that environment, ranged to 20 ppm, with an additional alarm at the room entry.

AS 1668.2 covers the mechanical ventilation these areas depend on.

Nitrous Oxide And Entonox

Entonox is a fixed 50:50 mixture of nitrous oxide and oxygen used as an inhaled analgesic in labour wards, emergency departments, paediatrics and minor procedure rooms, self administered by the patient through a demand valve.

A 50:50 mixture means the patient is inhaling nitrous oxide at 500,000 parts per million. The occupational question is what happens to the portion that does not stay in the patient.

Nitrous oxide is exhaled, and it leaks from cylinders, hoses, demand valves and pipeline connections. In a poorly ventilated room it accumulates as ambient nitrous oxide, and the people exposed are the midwives, nurses and clinicians standing beside the patient for a full shift, repeatedly. This is chronic occupational exposure rather than an acute event, which makes it easy to overlook because nothing ever appears to go wrong.

Detection serves two purposes here. Fixed monitoring in delivery rooms, recovery bays and gas store areas measures ambient levels, and it also verifies that scavenging and ventilation systems are performing as designed. A ventilation system nobody measures is a ventilation system nobody can vouch for.

Typical ranges are 0 to 100 ppm for ambient monitoring, 0 to 1,000 ppm where higher concentrations are expected, and oxygen to 30 percent by volume alongside. Leak detection at 0 to 1,000 ppm finds the source once ambient monitoring says there is one.

Verifying Anaesthetic Delivery

This application is different from the rest of the page and from most gas detection generally, because the risk is to the patient rather than to the staff.

Inhaled anaesthetics provide both amnesia and immobility, and the concentration delivered has to be accurate. Too much causes comatose states, significant drops in heart rate and death. Too little results in patients waking during procedures and experiencing severe pain. The correct dose depends on age, weight, height and the length and type of procedure, so the margin for equipment error is small.

Verifying the delivered concentration requires portable analysers calibrated for the specific agent, in both oxygen and air carrier bases. Typical ranges are halothane to 6 percent by volume, isoflurane to 8 percent, sevoflurane to 10 percent and desflurane to 20 percent, with oxygen to 30 percent.

Gastech supplies and calibrates that equipment. The calibration is the part that matters, since an analyser used to verify clinical accuracy is only useful if its own accuracy is certified and current.

IVF Laboratories

The most unusual application in the catalogue, and worth knowing about even if it is not yours.

An IVF laboratory looks sterile and can still be contaminated by volatile organic compounds, arriving from internal sources, adjacent rooms or the surrounding environment. Common ones are formaldehyde, isopropanol, xylene and refrigerants. HEPA filtration removes airborne particles and does nothing about VOCs, which is the gap most facilities do not realise they have.

Because ova, sperm and embryos are handled outside the body during IVF, they are directly exposed to whatever is in the laboratory air. Research shows VOC exposure negatively affects IVF success rates, and that levels above one part per million can impair the development of both mouse and human embryos.

So detection here runs at 800 parts per billion, which is an order of magnitude below what industrial monitoring concerns itself with. Photoionisation detection in both fixed and portable form is the technology, with the Falco 2 covering fixed installation.

One maintenance point is significant. PID lamps require regular cleaning and have a short life expectancy relative to other sensors, so this is an application with a real ongoing service requirement rather than an install and forget system.

Other Applications Across A Hospital

Beyond the clinical areas, a hospital carries the same infrastructure as any large building. Plant rooms with refrigerant systems. Boiler and generator rooms. Battery and uninterruptible power supply rooms generating hydrogen during charging. Laboratory areas using solvents and preserved specimens. Cryogenic storage using liquid nitrogen, with the same oxygen depletion risk as an MRI room. Carparks requiring carbon monoxide monitoring and ventilation control.

Each of those is covered under the relevant industry rather than repeated here, and talking to our Technical Consultants is the quickest way to work out what a whole site needs rather than one department at a time.

Who Regulates It

Healthcare facilities fall under general work health and safety law for staff exposure, so the regulator is WorkSafe WA, SafeWork NSW or Workplace Health and Safety Queensland depending on location. Safe Work Australia publishes the exposure standards those limits derive from without regulating or inspecting.

Clinical equipment and medical devices are regulated separately by the Therapeutic Goods Administration, which does not extend to workplace gas detection but does apply to the anaesthetic delivery equipment being verified.

Standards relevant to detection include AS 1668.2 for the mechanical ventilation these areas rely on, AS 2865:2009 for confined space entry, which applies to plant spaces and some storage areas, and AS/NZS 60079.29.2 for gas detector selection, installation, use and maintenance. Medical gas pipeline systems have their own installation and testing standard, which sits alongside rather than instead of the detection requirements.

What Gastech Supplies

Fixed gas detection for MRI rooms, sterilisation areas, delivery suites, laboratories, plant rooms and cryogenic storage, including sample draw arrangements where the detector cannot be located in the monitored space.

Portable instruments and single gas monitors for maintenance, spot checks and staff exposure monitoring.

PID instruments for laboratory and IVF applications requiring measurement at parts per billion.

Leak detectors for tracing nitrous oxide and medical gas pipeline leaks once ambient monitoring identifies a problem.

Accessories including sample pumps, sounders and beacons, which in this sector are frequently the components that make the installation work at all.

Behind them sit project engineering, NATA calibration and service, field service and fleet management, from WA, NSW and QLD.