What is considered to be a safe level of carbon monoxide?

Can fire alarms/carbon monoxide detectors go off by human presence?

• so at least once a week in the middle of the night when i walk below this stupid fire alarm it goes off, it says testing and goes through the whole alarm spoken fire fire, then goes to the last carbon monoxide level and does its alarm. it is sooooo weird, scares the H*** out of me every time, i replace the battery then it does it again a week later. But it only seems to do it when i walk underneith it at night, im now gong to start going in my room through my window, ps. we had the fire department come to our house at one point because of carbon monoxide and they said that it was one of the best alarms out their, it matched their detectors to decimal point. also it does have a different warning when the battery is low, it will actually tells us that the battery is low/

• Answer:

  A couple things come to mind. A dirty detector especially if it uses and optical sensor I had one that looked clean but there was apparently a spider that made a home in it at one time and the web kept blowing into the sensor. The alarms only last about 5 years so maybe it's hitting it's senior years. Unless you wear some kind of cologne it doesn't like I am tapped out on ideas. LOL Depending on they type of alarm if you have to replace it keep in mind that it has to be disposed of specially as most have some amount of radioactive material in them.