My 1 year old was messing around with the carbon monoxide alarm, 5 mins later it is beeping the low battery alert, not long after that it starts continuously beeping which indicates carbon monoxide detected. Took the batteries out and it stopped, but 10 minutes later it started again. Norbert has came and said it was fluctuating between 0-1. Is this a cause for concern? No idea how old the detector is as it was brought to my house by my mother in law. Bought a new alarm just to double check but not sure if it's safe to be here with my 1 year old? 

Since a carbon monoxide alarm is a life safety device and has no user serviceable parts (and its age is as yet unknown) I can only suggest you remove its batteries and dispose of it and rely on the new carbon monoxide alarm you have purchased and securely fix this new device out of reach of your 1 year old