| Like noxious gases |
| Most common of the noble gases |
| Gases or vapors that are dangerous to inhale |
| Elementary gases |
| Inactive, as gases |
| One of the inert gases |
| Accumulate gases on the surface |
| Swamp gases |
| Inert gases |
| Colorless gases |
| Refinery output |
| One of the noble gases |
| Input for a refinery |
| Of air or gases: Comb. form |
| What charcoal does to gases |
| Oil refinery input |
| Red gases (anag) |
| Certain gases |
| Petroleum refinery byproduct |
| Refinery by-product |
| Refinery gases |
| Site of world's largest oil refinery |
| Some nonreactive gases |
| Org. concerned with greenhouse gases |
| One of the inert gases in the periodic table of elements |
| Refinery residue |
| One of the 6 noble gases |
| Fuel gases |
| Major oil refinery port |
| Group that regulates greenhouse gases: Abbr. |