A combination of these products can produce hazardous gases. (petfriendlyhouse.com)
The burning of fossil fuels emits hazardous gases that affect not only humans, but every living organism on the planet. (gigaom.com)
These vivid images spur reasonable worries that fracking disturbs underground hydrogeology, resulting in leakage of hazardous gases into aquifers. (treehugger.com)