Possible Clues:

• Ozone layer pollutant
• Ozone-depleting chemical
• Ozone depleter, for short
• Freon letters
• Environmental hazard, for short
• Ozone layer pollutant, for short
• Ozone layer pollutant, briefly
• Phased-out refrigerant compound
• Ozone layer pollutant: abbr.
• Banned refrigerant, for short