Radon & Carbon Monoxide

We monitor radon and carbon monoxide in campus spaces, and coordinate related testing services.


Radon is a naturally occurring radioactive gas that comes from the natural breakdown in uranium in soil, rocks and water. Levels of radon are common in the air we breathe every day, and radon sometimes penetrates buildings through their foundations.

We conduct University-wide radon testing every 10 years in University buildings as part of a regular cycle of testing, assessment, and abatement procedures. In addition, we test buildings undergoing major construction or renovation. University-wide radon testing was last conducted in 2008. The next scheduled testing period begins in 2018.

Though radon is common in the everyday living environment, the U.S. Environmental Protection Agency has set guidelines that recommend limiting residential levels to 4 picocuries per liter (pCi/L) because of health risks associated with long-term exposure to high radon levels. Princeton sits on a geologic formation underlying the region that has an elevated uranium content, and the University will maintain a schedule of radon assessment to ensure that University buildings remain within EPA guidelines.

Carbon monoxide

Carbon monoxide (CO) is an odorless, colorless gas produced when fuels (such as wood, gasoline, heating oil, etc.) burn incompletely. Fireplaces, gas furnaces, gas stoves, charcoal grills, hot water heaters, gas ranges and other devices that use combustion are potential sources of CO.

CO detectors are devices that measure the presence of CO and sound an alarm when CO is detected at dangerous levels. They are located in campus residences, including dormitories, apartments, and graduate college annexes.

Our CO detectors take measurements every 2.5 minutes, and display a digital readout of current CO concentrations in parts per million (ppm). The alarm sounds when CO levels reach 100 ppm over 90 minutes, 200 ppm over 35 minutes or 400 ppm over 15 minutes – before the concentration of CO becomes high enough for adults to begin to experience symptoms.

If the alarm sounds, evacuate immediately. Treat all alarms as a real problem.

If your detector makes a chirping noise, the batteries need to be changed. Please call the Service Center at (609) 258-8000 to request a battery change.


Call the Service Center at (609) 258-8000 if you have questions about the scheduling and ordering of testing programs.

Call the Office of Environmental Health and Safety at (609) 258-5294 if you have questions related to health.

Service category

Did You Know

The Service Center (609-258-8000) is a centralized call center for every Facilities department. They handle approximately 60,000 inquiries per year via phone, web, and email.