Related Clues:
- Flammable hydrocarbon
- Gas used as a fuel
- Layer with a hole in it
- Earth-surrounding layer
- Water sterilizer
- Simple hydrocarbon
- Oxygen variety
- Endangered atmospheric layer
- Ultraviolet-ray blocker
- Ultraviolet light filter
- Colorless, odorless gas used as fuel
- Oxygen allotrope
- Damaged layer
- Natural gas product
- Shrinking layer