School CO Safety: Choosing the Right CO Detection Device Protects Not Just Life, But Health

A deep dive into CO alarms, CO monitoring devices, and why choosing the right one saves lives

If you’re responsible for a school, childcare center, campus facility, or any public building, you may have been told some version of: “Don’t worry; we have CO detectors installed.”

But here’s the biggest problem in school CO safety: When detection is installed, most buildings rely on carbon monoxide devices that weren’t designed for educational or multi-room environments. And many assume all CO detection devices work the same; they don’t.

In our recent five-year analysis of 103 press-reported CO incidents in educational buildings, we found:

• 13% had no CO detection at all

• 8% had detectors installed that did not alarm

• 56% had no detection information available

• Only 21% had alarms that successfully alerted

That means the majority of CO emergencies in schools happen without sufficient detection, or have detection that isn't right for the space.

Let’s break down the major categories of CO monitors, alarms, and systems, how they work, and where each fits in a complete CO safety plan.

1. Standard Single-Station CO Alarms (UL 2034) — Why Residential CO Detectors Aren’t Enough for Schools

These are the most familiar devices: battery-operated alarms, plug-in alarms, and combo smoke/CO alarms sold in stores. Most people assume these alarms will alert at the first sign of CO exposure, but that’s a dangerous misconception.

What these detectors are designed for

Single-family homes, not classrooms, labs, cafeterias, auditoriums, multi-room facilities, or early childhood centers.

They follow UL 2034, a residential CO alarm standard designed to prevent nuisance alarms, not ensure early warning.

Alarm timing under UL 2034

These devices may wait to audibly alarm:

• 70 ppm for 1–4 hours

• 150 ppm for 10–50 minutes

• 400 ppm within 4–15 minutes

In a classroom filled with children? That delay can mean the difference between mild exposure and mass hospitalization.

Where they fail

• No low-level detection

• No digital display in many models

• No building-wide notification

• Easily unplugged or removed

• Not supervised (if they stop working, no one knows)

Residential alarms = residential protection. Schools need far more.

2. Low-Level CO Alarms — The Best Carbon Monoxide Protection for Children, Pregnant People, Teachers, Caregivers, and Medically Vulnerable Groups

Low-level CO monitors detect and display carbon monoxide as low as 5 ppm, and typically alarm at 25–35 ppm, long before symptoms escalate.

Why low-level CO alarms matter

Children:

• breathe faster

• absorb CO faster

• develop symptoms sooner

• may not verbalize early warning signs

Pregnant people:

• are more susceptible to CO

• risk fetal harm at levels far below UL 2034 thresholds

Individuals with asthma, anemia, or cardiac conditions:

• are especially vulnerable to even low-level exposures

Great choice for:

• daycare, preschool spaces

• elementary classrooms

• nurse’s offices

• special education rooms

• spaces with repeated symptom complaints

Why we recommend these instead of standard CO alarms in these spaces:

They catch problems early, before the situation escalates into an emergency.

3. Portable CO Monitors (Single-Gas Meters) — Essential Carbon Monoxide Testing Tools for Schools and Maintenance

These handheld or clip-on devices give real-time CO readings, often updated every second.

Designed for

• verifying mechanical rooms

• checking boiler and HVAC performance

• confirming or ruling out CO after symptoms or complaints

• evaluating contractor activity

• testing kitchens, labs, and garages

Why every school maintenance team needs them

CO often spikes during:

• morning equipment start-up

• HVAC cycling

• cooking periods

• generator testing

• fuel-powered shop or maintenance work

Portable monitors and meters allow staff to identify issues before they become full-building emergencies.

Why they SHOULD NOT be used as the only protection

They do not:

• alarm building-wide

• protect empty rooms

• cover multiple areas

• detect when staff aren’t present

Meters are tools, not a safety system.

4. Multi-Gas Meters — For Complex CO Investigations and Safety Teams

Multi-gas detectors measure carbon monoxide plus other hazards like:

• oxygen

• combustible gases

• hydrogen sulfide

Why they’re useful in schools

Some CO emergencies occur alongside:

• natural gas leaks

• ventilation failures

• generator exhaust infiltration

• chemical events

• confined-space hazards

They provide crucial context for district safety teams and first responders.

5. Indoor Air Quality (IAQ) Monitoring Systems — Useful, but Not a Substitute for CO Alarms

IAQ systems can provide valuable insights, but they are not always life-safety devices.

What they track:

• CO (depending on model)

• CO₂

• VOCs

• humidity

• temperature

• particulates

Good for:

• transparency

• identifying ventilation issues

• tracking trends

IAQ monitoring is not a replacement for CO detection.

IAQ devices may:

• not meet UL standards

• not integrate with life-safety systems

• not provide building-wide alarms

They support building health, but do not replace CO alarms.

6. Hardwired CO Detection Systems — The Gold Standard for School and Campus CO Safety

These are true life-safety systems designed for complex buildings.

Hardwired systems provide:

• continuous power

• supervised wiring (system alerts if something fails)

• building-wide notification

• integration with fire alarm panels

• centralized reporting

• emergency responder activation

• coverage of multiple risk zones

Where these systems belong

These systems are ideal for:

• classrooms

• hallways

• mechanical rooms

• kitchens

• auditoriums

• gyms

• backstage areas

• CTE/vocational shops

• custodial storage

• bus garages

Why carbon monoxide detection systems matter

Across many school CO incidents:

• the affected area was far from the alarm location

• CO traveled through the ventilation and hallways

• alarms in hallways failed to detect classroom buildup

• symptoms appeared before any alarm sounded

A supervised, integrated detection system is the only method that provides whole-building life safety.

A Stronger Standard: Why CO Detection Belongs in Every Classroom, Office, and Occupied Space

Today’s building codes, including the International Fire Code (IFC), International Building Code (IBC), and International Existing Building Code (IEBC), require CO detection only in designated “high-risk” areas such as mechanical rooms, fuel-burning appliance areas, or garages.

But real-world incident data shows that carbon monoxide rarely stays in the room where it starts.

In our five-year analysis of 103 school-related CO incidents, exposure reached:

• classrooms,

• cafeterias,

• main offices,

• gyms,

• hallways, and

• early childhood spaces

—even when the CO source was nowhere nearby.

CO moves through:

• ductwork

• shared walls

• open ceilings

• pressurized hallways

• structural gaps

This is why we recommend a whole-building CO detection strategy:

• Every regularly occupied space should have CO detection

• Every educational building, regardless of age, should exceed the minimum code

• Older buildings unable to install hardwired systems should still deploy reliable single- or multi-station devices

• Using code minimums leave dangerous blind spots, especially in aging schools

Hardwired systems remain the gold standard. But when older buildings can’t immediately support them, administrators still have options that provide meaningful protection.

Codes create the floor. Safety demands we build above it.

What Type of CO Detection Does a School Actually Need?

The safest buildings layer multiple forms of protection:

• Hardwired CO detection system for building-wide, code-compliant life safety.

• Low-level CO alarms for childcare spaces, early learning, special education, and vulnerable populations.

• Portable CO monitors for maintenance, contractors, and emergency verification.

• Multi-gas meters for environmental health and first responders.

• IAQ monitoring for trend-tracking and transparency.

No single device provides complete protection.

Why Selecting the Right CO Technology Matters Now More Than Ever

From 2020–2025, press-reported CO incidents in U.S. schools and campuses resulted in:

• 285 students treated on-site

• 209 hospitalized

• 81 adults hospitalized

• 3 confirmed fatalities

• Over 100 mass evacuations

In many cases, detection failed because:

• detection was not installed or working properly

• the detection installed was not right for the space (creating false reassurance)

• low-level exposure went unnoticed

• symptoms mimicked seasonal illnesses

These events were preventable.

The Bottom Line on School CO Safety

Carbon monoxide protection isn’t about having a detector. It’s about having the right detection, in the right place, with the right capabilities, for the right environment.

When schools and childcare centers understand the differences between devices, they can make informed decisions that actually protect people, not just satisfy a fire marshal's or building inspector's checklist.