How long does it take chlorofluorocarbons (CFCs) to reach the upper atmosphere and affect the ozone layer?

It takes about a month for anything released at the Earth's surface to *start showing up* at the ozone layer. It may then takes seconds to many decades for it to finish doing what it will do, and be gone from the ozone layer. And it is important to note that not all of these heavier-than-air molecules may make it up to the ozone layer even in many lifetimes.