Gas detection systems: Invisible threats in your workplace

Carbon Monoxide (CO)

The silent asphyxiant

Carbon monoxide is colourless, odourless, and extremely dangerous. It binds to haemoglobin far more readily than oxygen, meaning exposure can cause headaches, dizziness, loss of coordination and, at worst, fatality.

It can form anywhere combustion takes place, such as boilers, generators, furnaces, plant rooms, and forklift operations. You’ll find it in boiler rooms with poorly maintained burners, in generator backup systems in enclosed spaces, and in workshops using petrol-powered tools. Even a small concentration in a poorly ventilated space can quickly incapacitate staff.

Real-life example

In a boiler house with ageing ventilation, CO levels can rise during peak heating demand. Workers may feel mildly unwell without realising they’re experiencing early CO poisoning. A fixed detector triggers an alarm long before symptoms appear, prompting ventilation checks and preventing a serious incident. Reliable gas detection would include a fixed CO detector that activates ventilation and shuts down the unit before staff enter the room, keeping everyone safe.

Fixed CO monitoring, automatic ventilation response, and regular combustion equipment servicing are key measures for protecting people and infrastructure.

Hydrogen Sulphide (H₂S)

The one that steals your sense of smell

Hydrogen sulphide is infamous for its “rotten egg” smell. It’s toxic, fast-acting, and unmistakable, until concentrations rise and your sense of smell shuts down entirely. Left unchecked, H₂S can cause respiratory damage, loss of consciousness, and be lethal even with short exposure.

Common risk areas include wastewater treatment sites, biogas and anaerobic digestion plants, oil and gas environments, and pumping stations.

Real-life example

At a wastewater site, routine pump maintenance often involves confined space entry. Portable detectors can alert the team if a pocket of H₂S is released from stagnant sludge. Additional solutions include area monitoring near pits, enclosed tanks, or sludge handling systems.

Methane (CH₄)

The explosive one

Methane behaves differently from the toxic gases above. It doesn’t poison; it displaces oxygen. Where methane accumulates, ignition risk increases dramatically. It’s common in landfill and biogas operations, mining and tunnelling, gas-fired boiler houses, and agricultural slurry pits.

Real-life example

Despite the quality of construction, buildings can develop hairline cracks. This becomes a serious risk in a biogas storage dome. If methane escapes into an adjacent plant room, it risks ignition from electrical systems. A CH₄ sensor detects the rising concentration and shuts down electrical systems to prevent ignition.

Other protective measures include good ventilation, automatic shutdown interlocks, and CH₄ gas detection systems.

Ammonia (NH₃)

The aggressive irritant

Ammonia is common in refrigeration, food manufacturing, and fertiliser storage. While widely used, incorrect handling can cause burns, respiratory irritation, and serious injury. Risks typically arise in cold stores, refrigerated warehouses, industrial chillers, plant rooms, and agricultural facilities.

Real-life example

Valves degrade over time and must be monitored. If a valve seal in a refrigeration compressor begins to fail and it isn’t detected quickly, NH₃ can concentrate, forming visible vapour and creating both safety and operational risks. NH₃ detectors positioned at low and high levels, proper ventilation, rapid alarm escalation, and sensors integrated into refrigeration controls can detect rising concentrations before they become hazardous.

Chlorine (Cl₂)

Highly reactive, used in water and chemical treatment

Chlorine gas is common in facilities using disinfectants or chemical processes, including water treatment plants, chemical dosing rooms, laboratories, and manufacturing sites.

Real-life example

Fermentation is an anaerobic process. Microbes consume oxygen and release CO₂. If a flue becomes blocked in a brewery fermentation room, CO₂ can accumulate overnight. Fixed detectors, ventilation interlocks, and alarm beacons are effective workplace gas detection solutions that prevent staff from unknowingly entering an oxygen-deficient space.

Carbon Dioxide (CO₂)

Everywhere, and dangerous at high concentrations

CO₂ builds silently, especially in confined areas where production, processing, or fermentation takes place. It’s commonly found in breweries, beverage processing plants, food production sites, enclosed plant rooms, and dry ice storage areas.

Real-life example

Fermentation is an anaerobic process. Microbes consume oxygen and release CO₂. If a flue becomes blocked in a brewery fermentation room, CO₂ can accumulate overnight. Fixed detectors, ventilation interlocks, and alarm beacons are effective workplace gas detection solutions that prevent staff from unknowingly entering an oxygen-deficient space.

Sulphur Dioxide (SO₂)

A by-product of combustion and industrial processes

SO₂ is corrosive and highly irritating to the respiratory system. It’s commonly found in metal refining plants, pulp and paper facilities, power generation sites, and fuel combustion systems.

Real-life example

A burner in a boiler house may run rich due to a faulty air damper, increasing SO₂ emissions. Sensors integrated with extraction and burner maintenance schedules can alarm early, allowing maintenance teams to reset the system and prevent exposure.