Indoor Air Pollutants

Mould thrives in warm, damp indoor spaces –and once it takes hold, it’s hard to ignore. From musty odours and visible damage to serious health impacts like asthma, respiratory infections and cognitive effects, mould is more than a nuisance. Some species, like black mould, can even be deadly. Learn how to spot, test and prevent mould growth – and protect your building and its occupants from long-term harm.

Airborne chemicals released by everyday items– from paints and furniture to perfumes and people. Indoors, they build up fast and can trigger symptoms like headaches, irritation, or even organ damage. Some VOCs are carcinogenic. Learn how to reduce exposure, monitor levels, and keep your indoor air safe –especially after renovations or in high-traffic buildings.

Formaldehyde (HCHO) is a potent indoor pollutant often released by new furniture, building materials, and cigarette smoke. It can linger for months – especially in warm, poorly ventilated spaces – causing eye and respiratory irritation, and in long-term exposure, even cancer. Learn how to detect, monitor, and reduce formaldehyde levels to protect occupant health, especially after construction or renovation.

BTEX compounds (benzene, toluene, ethylbenzene, and xylene) are highly toxic VOCs commonly found in indoor air from paints, varnishes, smoke, and cleaning products. Benzene, a known carcinogen, is particularly hazardous. These pollutants can damage major organs and impair cognition. Learn how to limit exposure, identify hidden sources, and keep your space safe with smart ventilation and monitoring.

PM10 is coarse particulate matter – tiny airborne particles from dust, smoke, building works, and even cleaning. While larger than PM2.5, PM10 still irritates the eyes, nose, throat, and lungs, especially for vulnerable groups. Indoor sources like cooking and candles can spike levels fast. Discover how to reduce PM10 exposure and protect your indoor air quality with smart ventilation and filtration.

PM2.5 are fine airborne particles that penetrate deep into the lungs and bloodstream – causing serious harm to the heart, lungs, and overall health. Emitted from sources like cooking, traffic, and industrial processes, PM2.5 is the most dangerous pollutant linked to air pollution-related illness. Learn how to detect, reduce, and manage PM2.5 in your indoor environment for healthier air and longer-term protection.

Carbon Monoxide (CO) is a deadly, invisible gas with no smell or taste – making it nearly impossible to detect without a monitor. Even low levels can trigger headaches and nausea, while high levels may cause unconsciousness or death. Learn how to spot sources of CO indoors, protect vulnerable occupants, and go beyond standard detectors with professional air quality monitoring.

Nitrogen Dioxide (NO₂) is a toxic gas mostly produced by fossil fuel combustion – especially from traffic. Indoors, it can seep in from outdoor air or come from sources like gas stoves or tobacco smoke. NO₂ irritates the lungs, worsens asthma, and can damage respiratory and cardiovascular health over time. Discover how to measure, manage, and minimise NO₂ exposure in your indoor spaces.

Nitrous Oxide (N₂O) – commonly used in medical settings and known for its euphoric effects – is usually harmless in low concentrations. But in poorly ventilated healthcare environments, it can pose serious risks to staff, including oxygen deprivation and neurological effects. Learn how to monitor and manage N₂O levels in medical spaces to keep indoor air safe for professionals and patients alike.

Sulphur Dioxide (SO₂) is a sharp-smelling gas released by burning coal, crude oil, and heavy ship fuel. Though UK emissions have dropped dramatically, SO₂ still infiltrates indoor spaces near industrial zones or ports. It irritates the lungs, eyes, and throat – especially in vulnerable groups. Learn how to monitor SO₂ levels, understand exposure limits, and protect your space with proper filtration and ventilation.

Hydrogen Sulphide (H₂S) is a flammable gas with a strong rotten-egg smell – often found near sewage systems, farms, or industrial sites. While detectable at low levels, high concentrations can be deadly within minutes. Even short-term exposure can affect vision, balance, and brain function. Learn how to recognise H₂S risks and keep your building safe from this potent pollutant.

Ozone (O₃) at ground level is a harmful air pollutant formed through sunlight-driven reactions between VOCs, methane, and NOx. It’s a powerful lung irritant and oxidiser – worsening asthma, triggering respiratory issues, and increasing cardiovascular risk. Indoors, ozone may enter from outside or be misused as a cleaning agent. Learn how to manage ozone safely and reduce exposure, especially in summer months.

Ammonia (NH₃) is a pungent gas mostly released from agriculture, waste, and decomposing organic matter. Though short-lived, it quickly transforms into harmful fine particles (PM2.5). In high doses – usually in industrial or farming settings – it can cause severe respiratory and skin damage. Learn how ammonia behaves indoors, how it contributes to other pollutants, and how to stay protected in high-risk environments.

Carbon Dioxide (CO₂) is naturally present in the air and produced by people, combustion, and industrial processes. While not harmful at low levels, high indoor CO₂ can cause drowsiness, poor focus, and headaches – contributing to sick building syndrome. It’s also a key indicator of poor ventilation. Learn how to monitor CO₂ effectively and keep your indoor spaces fresh, productive, and safe.

Radon is a radioactive gas that seeps into buildings from the ground, especially in high-emission areas or poorly ventilated spaces like basements. It’s invisible, odourless, and the second leading cause of lung cancer after smoking. Learn how to assess your risk, check UK radon maps, and take steps to reduce exposure through testing and ventilation.

Lead is a toxic heavy metal with no safe level of exposure – especially dangerous for children. Though banned in petrol and most paints, lead still lingers in older buildings, pipes, ceramics, and industrial emissions. It damages the brain, heart, kidneys, and reproductive system, and can accumulate in bones for decades. Learn how to test for lead and prevent long-term indoor contamination.