# Is a gas leak considered incomplete combustion?

This may be a dumb question, but if I leave the stove-top valve open (or I have a gas leak due broken tubing), would that be considered incomplete combustion?

From my knowledge, I figured a reaction is necessary for combustion to occur and that just the leaking of a gas would not qualify.

• Your right, why doubt? – Mithoron Aug 8 '16 at 2:05
• It is incomplete only of you think“no combustion” is part of the scale of incomplete combustion. Most people wouldn’t agree. – matt_black Aug 8 '16 at 7:18

In climate science we call these leaks fugitive emissions. The chemical composition of the emissions are different. If you just have a leak, the emissions will consist of what ever your fuel is made out of, probably methane. If you burn your fuel and the combustion is not perfect you might sill have a littel bit of the original fuel left but most will have been used up and formed CO (incomplete combustion), $\ce{CO_2}$ (complete combustion) and $\ce{H_2O}$ .