CFC
| Date | Clue |
|---|---|
| 2026-01-04 | Ozone no-no, for short |
| 2021-05-07 | Banned refrigerant, for short |
| 2019-10-14 | Freon initials |
| 2019-07-07 | Banned aerosol propellant, for short |
| 2018-04-06 | Banned pollutant, for short |
| 2015-07-10 | Freon letters |
| 2013-08-15 | Refrigerant inits. |
| 2010-11-13 | Freon initials |
| 2010-05-22 | Ozone hazard, for short |
| 2006-06-12 | Ozone depleter, for short |
| 2000-06-04 | Environmental hazard, for short |