We have a chest freezer in the basement.  There is NO diesel or other chemicals in the basement near the freezer.  But I've taken bread out of the freezer that's been in there for a while and it has an odd taste and smell.
I put some sugar coated donuts in there a while ago and I noticed the same smell but much fainter.  If I take bread from the refrigerator or the other freezer I don't smell or taste diesel.
The food in the basement freezer can be over a year old.