The Improving Air Quality for Our Children Act, 2023 requires every publicly-funded school and every licensed child care provider in Ontario to install certified carbon dioxide (CO2) monitors in every classroom and congregate space and to report measured CO2 levels to the Ministry of Education on a weekly basis. The bill sets a maximum threshold of 600 parts per million (ppm) above outdoor CO2 for occupied rooms, mandates annual recalibration of sensors, and requires the Ministry to publish regional outdoor CO2 baselines, raw data, and colour-coded reports.
The Act creates a province-wide measurement-and-transparency regime rather than prescribing only ventilation upgrades: it pairs specific monitor specifications and installation rules with a Ministry-developed Air Quality Action Plan (due within 60 days of the section coming into force) that lists temporary, intermediate and long-term responses. The law leaves enforcement details to regulation, which means school boards, child care operators and the Ministry must sort out funding, operational workflows and technical definitions to make the system meaningful in practice.
At a Glance
What It Does
The bill requires NDIR CO2 monitors with visible displays in every classroom and congregate space, installed to a specified mounting height and location, and recalibrated annually. It sets the maximum acceptable indoor CO2 level at 600 ppm above outdoor CO2 and requires weekly reporting of room-level average CO2 during occupied times and the percentage of occupied time above the threshold.
Who It Affects
All publicly-funded schools, child care providers licensed under the Child Care and Early Years Act, and school boards (which the Act makes responsible for ensuring monitor installation, including in contiguous leased spaces). The Ministry of Education must collect and publish data and produce an Air Quality Action Plan; HVAC professionals, maintenance staff, and procurement teams will face new technical and operational work.
Why It Matters
This bill shifts the focus from assumed ventilation upgrades to continuous measurement and public transparency, producing a province-wide dataset that will drive operational responses and capital planning. That transparency could accelerate remediation in poorly ventilated rooms but also creates immediate compliance, data-quality and funding questions for boards and providers.
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What This Bill Actually Does
The Act imposes a monitoring-first approach. It requires every eligible school and licensed child care centre to equip classrooms, portables and other shared spaces with CO2 monitors that use non-dispersive infrared (NDIR) sensors and include a visible display.
The law specifies where monitors must be mounted (1.3–1.5 m above finished floor), that they be located away from vents, windows and doors, at least 1.5 m from occupants, and continuously powered. The bill makes school boards responsible for installations in school spaces, and explicitly covers contiguous leased spaces occupied by child care centres or community groups.
On metrics and reporting, the Act sets the maximum indoor threshold at 600 ppm above outdoor CO2 and requires the Ministry to publish annual regional outdoor CO2 targets. Schools and child care providers must report to the Ministry at least once per week the room-level average daily CO2 during occupied times and the percentage of occupied time that exceeds the threshold.
The Ministry must publish those reports and the raw data in the format provided, and translate results into a three-colour public display (green, yellow, red) based on proximity to the threshold.The Ministry must develop and publish an Air Quality Action Plan within 60 days of that section coming into force. The Plan must be drafted in consultation with engineers, HVAC experts, industrial hygienists, unions, early childhood educators, principals and school boards, and must list temporary steps (portable filters, opening windows, relocating classes, reducing class size), intermediate steps (repairs, increased airflow) and long-term solutions (ventilation system upgrades).
The Plan must also provide product quality guidance (filtration and noise standards), qualifications for implementers, clear assignment of monitoring and response responsibilities, educational materials for staff, parents and children, and infographics to display beside monitors.Compliance and enforcement are left to regulation: the Minister may prescribe responses to non-compliance, including warnings and penalties. The Act requires annual recalibration of monitors and comes into force three months after Royal Assent, which gives school boards and operators a short implementation window to procure devices, establish reporting flows, and plan any remedial ventilation work.
The Five Things You Need to Know
The bill mandates NDIR CO2 sensors with a visible display in every classroom and congregate space (explicitly listing portables, gyms, cafeterias, libraries, staff rooms and main offices); school boards must ensure installation, including in contiguous leased spaces.
Monitors must be installed in the occupied space (not ductwork), mounted 1.3–1.5 metres above the floor, positioned away from vents/windows/doors, at least 1.5 metres from occupants, and powered for continuous monitoring.
The maximum indoor CO2 level is defined as 600 ppm above outdoor CO2; the Ministry must publish regional outdoor CO2 baseline targets annually to calculate that ceiling.
Schools and licensed child care operators must report weekly to the Ministry the average daily CO2 for each monitored room during occupied times and the percentage of occupied time above the maximum threshold; the Ministry must publish both processed reports (colour-coded) and the raw data as provided.
Within 60 days the Ministry must issue an Air Quality Action Plan with temporary, intermediate and long-term responses, product and qualification guidance, educational resources and infographics; the Minister may later make regulations prescribing penalties for non-compliance.
Section-by-Section Breakdown
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Definitions and administrative scope
This short section defines the Minister and Ministry as the Minister of Education and the Ministry of Education, respectively. While terse, it confines operational authority to the Ministry and frames who will receive reports, publish data and produce guidance—an important administrative allocation because subsequent obligations reference the Ministry rather than local public health units or school boards alone.
Who the Act covers
Section 2 applies the law to every publicly-funded school and every child care provider licensed under the Child Care and Early Years Act, 2014. That coverage pulls school boards and licensed private or non-profit child care operators into the same reporting regime and creates potential coordination requirements where child care centres are located in school space.
CO2 monitor specifications and installation rules
Section 3 prescribes device-level and siting requirements: monitors must use NDIR sensors, have visible displays, be mounted in occupied space at 1.3–1.5 m height, kept away from vents/windows/doors and at least 1.5 m from occupants, and be continuously powered. It also requires annual recalibration. Practically, this raises procurement standards (NDIR vs lower-cost alternatives), forces decisions about mains vs battery power, and creates clear installation checklists for maintenance staff and inspectors.
Maximum threshold and regional outdoor baselines
Section 4 sets the maximum indoor threshold at 600 ppm above outdoor CO2 and requires the Ministry to publish annual regional outdoor CO2 levels. Implementers will need to adopt a methodology for determining the applicable outdoor baseline (time, location, averaging approach), since the threshold depends on an outdoor reference rather than a single absolute indoor number.
Weekly reporting and public publication
Section 5 obliges weekly reporting of room-level average daily CO2 during occupied times and the percentage of occupied time exceeding the threshold. The Ministry must publish both public-facing colour-coded reports and the raw data in the format received. Operationally this creates a sustained data-collection and transfer obligation and raises questions about data standards, file formats, timestamps for 'occupied time' and the IT capacity required at board and provider levels.
Air Quality Action Plan requirements
Section 6 requires the Ministry to produce an Air Quality Action Plan within 60 days and lists consultees (engineers, HVAC experts, industrial hygienists, unions, principals, early childhood educators, school boards). The Plan must specify temporary/intermediate/long-term measures, product and qualification guidance, and educational materials. The consultation list and detailed guidance aim to standardize responses across the province but will also be the vehicle for technical clarifications—e.g., acceptable portable filter types and noise limits.
Incident reporting, regulations and commencement
Section 7 requires schools and child care centres to report to the Ministry when CO2 exceeds the maximum threshold and for the Ministry to publish those reports. Section 8 allows the Minister to make regulations prescribing measures for non-compliance, including warnings and penalties, but leaves the specifics to future rule-making. Section 9 sets commencement at three months after Royal Assent, giving a short implementation window; procurement, staffing and data systems will need to be mobilized quickly.
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Explore this topic in Codify Search →Who Benefits and Who Bears the Cost
Every bill creates winners and losers. Here's who stands to gain and who bears the cost.
Who Benefits
- Students and children: They gain continuous monitoring and public reporting intended to reduce time spent in poorly ventilated rooms, which evidence links to reduced respiratory symptoms and better learning outcomes.
- Teachers and education workers: Improved detection of ventilation problems and recommended mitigation measures (portable filters, relocations, system upgrades) should reduce absenteeism and improve working conditions over time.
- Parents and local communities: Public access to colour-coded room-level data and raw datasets increases transparency and allows parents to assess the environment where their children spend time.
- Public health and planners: The province-wide dataset will provide a standardized source of room-level ventilation signals to inform outbreak responses, capital investment priorities and targeted remediation.
- HVAC and indoor-air professionals: Demand for assessments, repairs, recalibration services and ventilation upgrades will increase, creating market opportunities for qualified contractors and consultants.
Who Bears the Cost
- School boards: They must procure, install and maintain monitors (including powering and annual recalibration), implement reporting workflows, respond to exceedances and potentially fund ventilation upgrades—creating capital and operating costs.
- Licensed child care operators (especially small providers): They face equipment and reporting obligations, and where they operate independently from the board may struggle to absorb procurement and technical costs.
- Ministry of Education: The Ministry must build or expand data intake and publication systems, develop the Air Quality Action Plan, publish regional baselines and raw data, and potentially administer enforcement or penalty regimes.
- Facilities and maintenance teams: Staff must manage device installation location constraints, continuous power, recalibration scheduling and immediate mitigation steps during exceedances, adding to workload and possibly requiring new training.
- Local budgets and capital planning: Long-term ventilation upgrades identified by the Plan or triggered by repeated exceedances could require significant capital investment from boards or the province.
Key Issues
The Core Tension
The bill balances two legitimate goals—rapid, province-wide measurement and public transparency to protect children's health versus the technical limits, operational burden and funding costs of creating a reliable monitoring regime; demanding measurement without clear funding and data-quality controls risks producing noisy public data and uneven remediation across boards.
The Act relies on CO2 as a proxy for ventilation and airborne-transmission risk, which is practical but imperfect. CO2 tracks exhaled breath concentration well in occupied spaces, but it does not measure pathogen load, particulate pollution, humidity or other indoor contaminants.
The single threshold—600 ppm above outdoor—ties acceptability to a moving outdoor baseline: implementers must adopt consistent methods for measuring or selecting 'outdoor CO2' by region and period, otherwise the ceiling will vary unpredictably. The requirement to publish raw data in the format provided increases transparency but also exposes variability in measurement approaches and timestamps, which can complicate interpretation by the public.
Operationally, weekly averaged reporting and a colour-coded summary can obscure short-term spikes that matter for infection control. The Act requires weekly averages and percent-time-above-threshold metrics rather than mandatory real-time alarms or automatic behavioural triggers, which may delay responses during acute events.
Annual recalibration is helpful but NDIR sensors drift and can produce systematic bias between devices; without stringent procurement standards and centralized data validation, the published dataset risks inconsistent quality. Finally, the Act leaves funding for devices, recalibration, IT connections and long-term HVAC upgrades unspecified, pushing a large and immediate financial burden onto school boards and some child care operators while giving the Ministry discretion over enforcement through future regulations.
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