The manual for the LP/CO detector says it will detect a number of gases, but it is not certified for anything but LP and CO. I have set it off by spraying cleaning fluid near it. We have set it off with the alcohol vapor from wine in a slow cooker.
We had several false alarms that I now believe to have been caused by hydrogen gas from the batteries, which are under the step beside the LP/CO detector in our Sunseeker. After some alarms I shut off the LP at the tank but still had alarms. When I removed the battery cover, the detector immediately alarmed. I am sure methane will set them off, and many have blamed that on their dog(s). Of course, guys have been blaming methane on their dogs for generations.