Related Clues:
- Water sterilizer
- Oxygen variety
- Endangered atmospheric layer
- Ultraviolet-ray blocker
- Ultraviolet light filter
- Oxygen allotrope
- Damaged layer
- Shrinking layer
- Layer to be concerned about
- Skinny?
- Pungent gas
- Layer that absorbs ultraviolet rays
- Ultraviolet filterer
- Layer with a problematic hole
- Atmospheric screen