A school is a transmission environment built to a specification no epidemiologist would approve: several hundred people, many of them poor at hand hygiene, sharing air, surfaces and equipment for six hours a day, nine months a year. This page sets out which organisms actually drive absence, where each one lives, and — importantly — which ones a cleaning programme can influence and which it cannot.
About claims on this page
EcoloxTech generators produce a hypochlorous acid solution on site. They are regulated by the EPA as devices, are not registered disinfectants, and we make no efficacy claims for them or for the solution they produce. The only EcoloxTech product with disinfection claims is HOCl-AS200 (EPA Reg. No. 101112-1), used according to its label. Research cited here describes published studies of hypochlorous acid and electrolysed water under their own test conditions; it is not a claim for any product.
Norovirus, the one that closes schools
If a school has a memorable outbreak, it is usually this. Norovirus has a very low infectious dose, is non-enveloped and therefore more robust than the enveloped viruses people benchmark against, sheds heavily including after symptoms stop, and spreads person to person once established.
The school-specific feature is the vomiting incident. A child is sick in a classroom or a corridor, and the contamination is not confined to the visible spot — aerosolised material spreads across a radius. Handled with a paper towel and a quick wipe, it seeds the building. Handled with a written procedure, it usually stops there.
| Control | What good looks like |
|---|---|
| Vomiting-incident procedure | Written, kept with the kit, known by whoever is on shift: cordon generously, PPE, absorb and remove, clean, sanitise with adequate contact time, dispose as directed, record |
| Exclusion rule | A defined period after symptoms stop, applied consistently, including to staff. This does more than any cleaning step |
| Hand hygiene | Soap and water rather than gel where hands are soiled; supervised for younger children; stations that are stocked |
| High-touch frequency | Escalated when absence rises, concentrated on restrooms, door furniture, rails and shared equipment |
| Absence monitoring | Someone reviewing it weekly, so a pattern is caught in days rather than a fortnight |
Published work on hypochlorous acid against norovirus and its surrogates is in the hub — virucidal efficacy on surfaces against murine norovirus and liquid and fog application against human norovirus on surfaces — described as research under its own test conditions. Generated solution carries no efficacy claims; where a documented claim is required, a registered product used per its label is the answer.
Respiratory viruses
Influenza, RSV, rhinoviruses and coronaviruses account for most winter absence, and schools amplify them efficiently. The honest hierarchy of controls puts ventilation and case management first: air handling, keeping symptomatic children and staff at home, and vaccination where it applies. Surface work and hand hygiene are real but secondary contributors, because the dominant routes are airborne and close-contact.
That hierarchy matters commercially as well as epidemiologically, because it is the opposite of what a cleaning supplier is incentivised to say. A district that spends its winter budget on surface chemistry while leaving classroom ventilation unexamined has optimised the smaller variable. The research hub holds work on hypochlorous acid and influenza viruses, neutral hypochlorous acid against avian influenza virus and other avian viruses, as research rather than as a recommendation for respiratory control.
Athletics: MRSA, dermatophytes and shared equipment
Sports programmes are their own microbiological environment, and a separate part of the cleaning policy.
| Organism | Where | Control |
|---|---|---|
| Staphylococcus aureus, including MRSA | Wrestling and gymnastics mats, shared pads and helmets, benches, weight equipment, towels | Cleaning between sessions with adequate dwell; skin checks; no sharing of towels or kit; cover wounds; exclude until cleared |
| Dermatophytes (ringworm, tinea) | Mats, locker room floors, showers | Mat cleaning with coverage and contact time; footwear discipline in wet areas |
| Candida and other fungi | Wet areas, shower floors | Floor frequency and drainage |
| Enteroviruses and respiratory viruses | Shared water bottles, team transport | No shared bottles; transport included in the cleaning round |
The recurring failure is contact time. A wrestling mat given a quick pass with a cloth between sessions has been wiped, not sanitised. Whatever product is used, the mat needs coverage and the dwell the label specifies, and the schedule has to allow for it — which is a timetabling decision as much as a cleaning one. Research in the hub includes dilute hypochlorite and electrochemically activated saline against MRSA and fungicidal efficiency of electrolysed oxidising water on Candida albicans, cited as research.
Early years and childcare
Pre-K, childcare and early elementary settings have a different organism mix, driven by diapering, mouthing of toys and children who cannot manage their own hygiene.
- Enteroviruses — hand, foot and mouth disease, spread through shared toys and surfaces.
- Shigella and Giardia — faecal-oral routes, with diapering areas and hand hygiene as the controls.
- Cryptosporidium — see below; it resists chlorine chemistry.
- Respiratory viruses — at higher rates than older year groups.
Two structural controls matter more than the product: a toy rotation and cleaning cycle that actually happens (mouthable toys out of circulation until cleaned, not wiped in situ), and a diapering procedure with surface treatment after every change. State childcare licensing rules are often stricter than district policy here and take precedence.
What chlorine chemistry does not handle
A page like this is more useful if it says what does not work.
Cryptosporidium is notably resistant to chlorine-based disinfection. Where it is the concern — typically water play, a childcare outbreak or a contaminated recreational water source — the controls are exclusion, hand hygiene, and the health department’s specific guidance. No routine surface chemistry is the answer, and a supplier who implies otherwise is worth distrusting on everything else too.
Head lice are not an environmental problem at all. Classroom cleaning, spraying furniture and bagging soft toys have no meaningful effect, and the practice persists mainly because it looks like action. It belongs in a health policy, not a cleaning one.
Bacterial spores are the hard case for every oxidising chemistry, and are rarely the relevant hazard in a school.
The control that outperforms everything
Hand hygiene does more in a school than any surface programme, and it is the cheapest intervention available. The variables are all practical: whether sinks and stations are where children actually pass, whether soap and towels are stocked at 2pm and not just at 8am, whether younger children are supervised, and whether staff model it.
The hub holds in-vitro work on hypochlorous acid as a skin antiseptic, hypochlorous acid as an alternative skin antiseptic, an in vitro comparison, cited as research; it is not a recommendation for school hand hygiene, and the products at your stations should be the ones chosen for that purpose. The point here is the allocation: a district weighing a surface-cleaning upgrade against fixing its hand-hygiene stations should look hard at the second option first.
Reading absence data
The most useful microbiological instrument in a school is the attendance system, and it is almost always under-used. Absence tells you something is moving through the building days before anyone reports a pattern, and it tells you where — a single class, a year group, a bus route, a team.
Three habits turn it into a control. Look at it weekly rather than when someone mentions it. Look at the shape as well as the number: gastrointestinal symptoms clustering in one class behaves differently from respiratory absence spread evenly across a building, and they call for different responses. And include staff absence, which is often the earlier signal, because adults come to work sick for longer than children are sent to school sick.
None of this requires new software. It requires someone whose job it is to look, and a rule about what happens when the number moves. That is the cheapest improvement available to most districts, and it makes the cleaning programme more effective without changing a single product.
Frequently asked questions
Does HOCl kill norovirus?
Generated solution carries no efficacy claims, so we do not make that statement. The hub holds published research on hypochlorous acid and norovirus surrogates, described as research. Where a documented claim is needed, use a registered product per its label.
Should we deep-clean classrooms during flu season?
Increase high-touch frequency and look hard at ventilation and exclusion rules. A deep clean is visible but usually less effective than doing the daily round properly.
What is the right way to clean wrestling mats?
Coverage and contact time, on a schedule that the timetable actually allows, using a product whose directions you follow. The failure mode is almost always a quick wipe between sessions.
Do we need to do anything about head lice?
Not environmentally. It is a health policy matter; classroom spraying has no meaningful effect.
What about Cryptosporidium?
It resists chlorine-based chemistry. Follow your health department’s guidance, and rely on exclusion and hand hygiene rather than a surface product.