Chemistry
The Chemistry of Atmospheric Ozone Formation and Depletion Cycles
Quick fact
A single chlorine atom from a CFC molecule can destroy up to 100,000 ozone molecules before it is removed from the stratosphere, and it can remain active for over a century.
Why this is interesting
Every second, the sky above you is quietly building a fragile shield against the sun's most violent rays—yet we once managed to tear a hole in it with a can of hairspray. How can a few chlorine atoms from a spray can destroy something as vast as the ozone layer?