| Answer | Crossword Clue |
|---|---|
| METHANE | Dangerous mine gas. |
| FIREDAMP | Dangerous mine gas. |
| DAMP | Dangerous mine gas |
| METHANE | Dangerous buildup in a mine |
| GASSES | Dangerous buildup in a mine |
| RADON | Dangerous gas |
| RADON | Dangerous inert gas |
| RADON | Dangerous noble gas |
| RADON | Dangerous household gas |
