Expert: Henry Boyter - 1/21/2007

Question
What gas is emitted when aluminum melts/burns? Could that gas set off a CO alarm?  Background: In the past my CO alarm occasionally sounded when my gas range oven was on. The oven was checked by "experts" and found to be working properly. However I noticed that a comercial oven liner had partially melted in the bottom of the oven. After removing most of the aluminum residue the alarm no longer sounds (but appears to be working properly).  

Answer
A couple of possibilities.  It don't think it is the aluminum itself.

1. A gas range puts out CO if operating normally. It is the result of the burning process and is not dangerous, unless you have a faulty oven. If the CO detector is too close, or too sensitive, or the gas mix a little different than normal, I could see it setting off.

2.  Gas burners will naturally have deposits of soot on them.  If these build up, but are still not visible, they still could burn off producing CO.

3. My best thought is that either material that has evaporated (like oils) on this liner or spilled on the liner was burning off and when you removed it there was no more source for the CO.  Also, the liner may have had some type of film that was burned off.

You will never know for sure.  By the way aluminum has a melting point of >1200F.  I hope your oven doesn't go that high!!  It also will not burn under those conditions.  If you see burn, it is something else burning and depositing on the aluminum.