Hairspray sets them off, some cleaners. We have had this happen, if you can associate why it went off to something then you are probably fine.
Propane has a distinct odor on purpose it is injected into it because the gas is naturally odorless and sinks to the floor.
A true story. I stepped onto the step of our MH and my wife said from inside loudly "I smell gas"! So did I. I turned quickly and went to the propane tank and shut it off. As I did a friend was right behind me and I ask him if he would go inside and check it out (former Fireman). As I approached the door after shutting down the propane my friend came out and said with a grin "you guys are having broccoli tonight"!
I do all my own stunts
03 Dolphin LX 6355, Workhorse W22, 8.1 vortec, 04 CR-V, Blue Ox, Brake Pro----Norm, Barb and
Doc(He's a PhD)