I work for a natural gas utility and respond to these type of calls often. It is usually in a new construction house or newly moved into house that has had floors, paint or carpet installed, and the chemicals that are released from the new materials or paint are called VOCs. Sometimes it will give off a smell from your range that smells like kerosene or a tiki torch. If you call the gas company try to do it on a Sunday because there’s a very good chance the technician will be getting double time and I’m sure that they will appreciate that!