Every breath crosses the alveolar membrane in under a second — carrying whatever the building holds,
or whatever contaminants infiltrate from outside, directly into the bloodstream.
PM2.5. CO₂. VOCs. H₂S. The WHO has named indoor air pollution
the world's largest single environmental health risk. Not outdoor. Indoor.
Solivox Indoor exists to make that risk visible, measurable, and manageable.
At 2.5 micrometres — roughly 1/30th the width of a human hair — these particles are too small to be stopped by the nose or throat. They reach the alveoli: the tiny air sacs where gas exchange happens. There, they cross directly into the bloodstream. Once in circulation, PM2.5 triggers systemic inflammation, accelerates arterial hardening, and reaches the brain. Long-term exposure is associated with ischaemic heart disease, stroke, lung cancer, and cognitive decline. The WHO revised its limit down from 10 μg/m³ to 5 μg/m³ in 2021 — because no level is truly safe.
CO₂ is not toxic at typical indoor levels — but it is cognitively disabling. As CO₂ rises in a room, it accumulates in the blood, shifting blood pH and reducing the oxygen gradient that drives neurological function. Harvard's landmark COGfx study found that at 1,000 ppm — easily reached in a full meeting room by mid-morning — complex decision-making scores dropped by 15%. At 2,500 ppm, scores dropped 50%. A full classroom reaches these levels before the first break. CO₂ is the most reliable real-time proxy for ventilation quality: when it climbs, everything in the room is accumulating.
Thousands of chemical compounds off-gas continuously from building materials, furniture, flooring, cleaning agents, adhesives, and paint — the physical fabric of every modern interior. Many are known or suspected carcinogens: benzene, formaldehyde, trichloroethylene. Others cause acute neurological symptoms at concentrations that produce no detectable smell. The WHO's 2021 guidelines acknowledge that for several VOC compounds — particularly formaldehyde — there is no safe threshold. Indoor VOC concentrations are typically two to five times higher than outdoor levels.
H₂S is the pollutant South Africans have been forced to confront. Johannesburg has experienced two episodes in 2026 alone — both peaking at 36–37 ppb at city monitoring stations. Below the threshold of detectable smell, H₂S begins interfering with cytochrome oxidase, the enzyme at the end of the mitochondrial electron transport chain. It literally interrupts the way cells produce energy. At sub-odour concentrations — levels your nose cannot register — University of Michigan research has documented neurological effects including headache, impaired memory, and reduced attention span on repeated exposure.
Humidity and temperature are not comfort metrics — they are biological multipliers for every other pollutant in the space. Below 40% relative humidity, the mucous membranes lining the respiratory tract dry out: the body's primary mechanical defence against inhaled particles and pathogens is compromised. Above 60% RH, mould growth accelerates, dust mites thrive, and VOC off-gassing from building materials increases. Temperature directly modulates chemical reaction rates — including the reactions that produce secondary pollutants from VOC precursors. A room at the wrong humidity is a room where everything else hits harder.
NO₂ infiltrates from outside — from traffic, industrial emissions, and combustion — and accumulates indoors because it reacts slowly and is not easily removed by standard ventilation. It is a potent respiratory irritant at concentrations that produce no immediate symptoms: it inflames the bronchial lining, reduces lung function over time, and increases susceptibility to respiratory infections. The WHO revised its annual limit down from 40 μg/m³ to 10 μg/m³ in 2021 — a 75% reduction — based on evidence of cardiovascular and pulmonary damage at previously considered safe levels. Every South African preschool tested in Mpumalanga exceeded this new WHO threshold.
By mid-morning in a full classroom, CO₂ has already crossed the threshold that measurably impairs the prefrontal functions children need for reading, reasoning, and retention. It happens before the first break. Nobody can smell it. Most schools have no way of knowing it is happening. Harvard research puts the cognitive performance gap between high-quality and poor-quality indoor air at 101% — not a marginal improvement, a fundamental one.
Beyond CO₂, PM2.5 from outdoor pollution infiltrates through ventilation. VOCs off-gas continuously from furniture, flooring, whiteboard markers, and cleaning agents. In South African schools near any industrial or high-traffic zone, this baseline is already elevated before a single child walks in. The air your students are breathing is shaping what they are capable of learning that day — and no school in this country is currently measuring it continuously.
A ward where CO₂ has crept above 1,000 ppm is a ward where the nurses and doctors making decisions are cognitively impaired — mildly, measurably, and invisibly. At the same time, patients who are already physiologically compromised are absorbing PM2.5 that has infiltrated through the ventilation system, and volatile compounds that off-gas continuously from cleaning agents, synthetic flooring, and pharmaceutical storage.
Private healthcare in South Africa is built on a promise of a higher standard of care. That standard should extend to every cubic metre of air in every ward, theatre anteroom, and consultation room. Solivox Indoor provides the continuous monitoring and documented response protocols that allow a healthcare facility to prove — to regulators, to accreditation bodies, and to patients — that it is taking that promise seriously.
Harvard's COGfx study found an 8% productivity gain, a 30% reduction in sick building symptoms, and 101% higher cognitive scores in buildings with verified air quality management. In the South African market, GBCSA green-certified buildings command rental premiums of up to 27%. These are not soft benefits — they are quantified, documented, and increasingly expected.
The shift is already underway. Major institutional tenants are building IAQ requirements into lease negotiations. ESG reporting frameworks are expanding to include indoor environment quality data. GBCSA Green Star ratings now embed air quality performance criteria. Building owners who can produce continuous, sensor-verified air quality records are not just differentiating — they are future-proofing their asset against a compliance environment that is tightening every year.
Bloomberg's 2024 investigation found the area surrounding Sasol's Sasolburg complex registering the highest PM2.5 concentrations on the planet according to OpenAQ. The 1.7 million residents live adjacent to a petrochemicals complex, steel mill, coal plant, and oil refinery. This is the outdoor baseline infiltrating every building in the area without continuous monitoring.
City monitoring stations in Buccleuch and Alexandra confirmed hydrogen sulphide at 36–37 ppb. At these concentrations, every school, hospital, and office building in the affected radius had elevated H₂S indoors. Without indoor monitoring, no facility could have known, quantified the exposure, or triggered a protocol response.
Government-commissioned studies found children at primary schools in Embalenhle — adjacent to Sasol's Secunda plant — had some of the poorest respiratory health metrics in the country. These are children attending school inside buildings with no IAQ monitoring. The outdoor pollution is known. The indoor exposure is entirely unmeasured.
A 2024 study in Public Health Challenges measured NO₂ and SO₂ at 13 preschools across 7 Mpumalanga districts. All readings exceeded the WHO's 10 μg/m³ threshold. Not one preschool had indoor monitoring. These children had been breathing non-compliant air for years, with no record, no alert, and no response.
The SA High Court ruled that Highveld air quality violates citizens' constitutional rights — implicating Eskom and Sasol directly. The government acknowledges 40% of the population lives more than 25km from any monitoring station. The regulatory gap is established. Indoor monitoring is the only available response for building operators.
The Green Building Council South Africa has embedded indoor environment quality — including air quality monitoring and ventilation performance — into its Green Star rating system. Buildings seeking or renewing certification will increasingly require documented IAQ data. The market for verified indoor air quality is not emerging. It is here.
of the global population lives in areas that do not meet WHO air quality guideline levels. South Africa is not an exception — it is one of the most affected countries on the continent.
deaths in 2021 were attributable to air pollution — making it the world's second largest environmental cause of death. The majority of that exposure happens indoors.
rental premium commanded by GBCSA green-certified buildings in South Africa. IAQ monitoring is now embedded in the Green Star rating criteria.
H₂S — the concentration at which Johannesburg's sulphur episodes routinely peak — is already below the threshold detectable by smell, yet is associated with documented neurological effects on prolonged exposure.
Solivox Indoor is a South African indoor air quality intelligence platform built for the specific environmental and regulatory context of this country. Not a global product adapted for Africa. Built here, for conditions here — the outdoor pollution infiltrating buildings, the absence of domestic IAQ regulation, and the growing expectation from affluent clients that their spaces meet an international standard of care.
Our background is in structural and environmental engineering, with direct project delivery across South Africa for government, healthcare, and infrastructure clients. We understand what facility managers can realistically act on, what compliance documentation looks like in South Africa, and how to build systems that last in this environment.
Our action plan library is calibrated to WHO 2021 air quality guidelines — the international standard South African law has not yet formally adopted but is under increasing pressure to align with. The regulatory direction is set. When that alignment happens, our clients will already be fully compliant. Those without continuous monitoring will face a reclassification they are not prepared for.
Every Solivox Indoor deployment comes with a facility-specific onboarding: sensor placement mapped to occupancy patterns, thresholds set to the nature of the space, and action plans written for the actual staff who will need to respond. We do not sell hardware. We build an air quality programme for your building.
Compact multi-parameter sensors measure PM2.5, CO₂, total VOCs, H₂S, temperature, and relative humidity simultaneously — every 60 seconds. Wireless. No cabling, no contractor, no disruption to the building. A typical school or office floor is instrumented and transmitting live data in under an hour.
A single dashboard surfaces every sensor across every room in real time. Colour-coded by pollutant against WHO and SANS thresholds. Accessible on any device. Designed to be understood without training by a school principal, a ward manager, or a property director — not just a facilities engineer.
When a pollutant crosses a threshold, the system does not just send an alert — it delivers a prescribed action plan to the relevant staff member: ventilate this room, relocate these occupants, notify this contact, log this event. Written for the specific facility type. Executable without specialist knowledge. This is what separates Solivox Indoor from every other product in this category.
Every sensor reading, threshold event, and staff action is logged automatically and formatted into audit-ready reports. Exportable for DoE inspections, GBCSA certification submissions, healthcare accreditation bodies, insurers, and ESG disclosures. The documentation exists before anyone asks for it.
The tools exist. The data is available. The buildings that will define the next decade of South African property, education, and healthcare are the ones that can demonstrate what their occupants are breathing. Get in touch — we will show you what your building is doing right now.