If CO readings are at 7 ppm and no symptoms are exhibited by occupants, what should be advised?

In this scenario, when carbon monoxide (CO) readings are at 7 parts per million (ppm) and no symptoms are exhibited by occupants, the advisable action is to check the CO detector per the manufacturer's recommendations. This is because a reading of 7 ppm is generally considered to be a low, non-threatening level of carbon monoxide.

At low levels like this, typical protocols might include evaluating the function of the CO detector to ensure it is operating correctly and hasn’t malfunctioned or given a false reading. Regular checks and maintenance of CO detectors are crucial for overall safety, as they are the first line of defense against harmful CO accumulations in a building.

If higher levels of CO were detected or occupants exhibited symptoms (such as headaches, dizziness, or nausea), then more urgent actions, such as evacuation or contacting emergency services, would warrant consideration. However, in this case, with low readings and no symptoms, focusing on the detector’s condition is appropriate.