Understanding Carbon Monoxide Levels
Carbon monoxide (CO) levels in a home are typically measured over time. Carbon monoxide detectors are time-weighted alarms, meaning they measure the buildup of carbon monoxide in a house as time passes.
For a person to begin feeling the effects of carbon monoxide poisoning, they would need to be exposed to a carbon monoxide level of 50 parts per million (PPM) for eight hours.
How Carbon Monoxide Detectors Work
Different carbon monoxide detectors will sound at the detection of varying CO ppm levels. A CO sensor needs to meet the sensitivity requirements of Underwriters Laboratories UL2034 Single and Multiple Station Carbon Monoxide Alarms. Per these requirements, standard CO sensors will typically not alarm at levels below 30 ppm.
However, carbon monoxide alarms with ultra-sensitive detection will indicate low levels of CO below 30 ppm, which may have health implications for those suffering from pre-existing conditions.
How Much Carbon Monoxide Is Dangerous?
Levels of carbon monoxide exposure range from low to dangerous:
- Low level: 50 PPM and less
- Mid-level: Between 51 PPM and 100 PPM
- High level: Greater than 101 PPM if no one is experiencing symptoms
- Dangerous level: Greater than 101 PPM if someone is experiencing symptoms
When Will Carbon Monoxide Levels Set Off Your Alarm?
- 40 PPM: 10 hours
- 50 PPM: 8 hours
- 70 PPM: 1 to 4 hours
- 150 PPM: 10 to 50 minutes
- 400 PPM: 4 to 15 minutes
Carbon Monoxide Levels and Their Symptoms
If your carbon monoxide alarm sounds, or you suspect you are experiencing symptoms of carbon monoxide poisoning, you should immediately leave your home and call 9-1-1. Here are some of the symptoms you can expect from carbon monoxide exposure:
- 50 PPM: None for healthy adults. According to the Occupational Safety & Health Administration (OSHA), this is the maximum allowable concentration for continuous exposure for healthy adults in any eight-hour period.
- 200 PPM: Slight headache, fatigue, dizziness, and nausea after two to three hours.
- 400 PPM: Frontal headaches within one to two hours. Life-threatening after three hours.
- 800 PPM: Dizziness, nausea, and convulsions within 45 minutes. Unconsciousness within two hours. Death within two to three hours.
- 1,600 PPM: Headache, dizziness, and nausea within 20 minutes. Death within one hour.
Additional Information
For more information about your specific alarm, refer to your user’s manual. To ensure CO alarms detect carbon monoxide accurately, it’s important to properly place and install alarms. Become familiar with frequently asked questions on the use and capabilities of carbon monoxide detectors to help protect your home and family.
How Many Carbon Monoxide Alarms Do I Need?
Carbon monoxide alarms should be installed on every level of the home and in sleeping areas.
Proper Smoke Detector Disposal
Learn what to do with old smoke detectors and how to properly dispose of fire alarms and fire extinguishers when it’s time to replace expired products.
How do I throw away my alarms and fire extinguishers?
Replacing old smoke detectors and fire extinguishers is a key part of fire safety, but knowing how to properly dispose of old or expired equipment is also important. Some devices can contain hazardous materials that need to be disposed of with care.
Can You Use Your Carbon Monoxide Alarm in Multiple Locations?
Carbon Monoxide alarms are not for short term testing, or a "quick check" for CO levels. You should install your alarm and leave it in one place.
Why Does My Battery Only Last One Month?
This is usually caused by the absence of AC power to the smoke alarm.