The class of anthropogenic compounds responsible for the breakdown of stratospheric ozone are known as

Chlorofluorocarbon

Explanation:

Such type of the area of the stratosphere of the earth that prevents the ultraviolet radiation of the sun by absorbing is known as the Ozone layer. This layer is also known as the shield of the earth because it protects the earth's surface and thus the organisms on the earth from ultraviolet radiation. The ozone layer is made up of the high concentration of the molecule. There are many gases and some other compounds that are responsible to break this layer by their chemical activity such as chlorofluorocarbon and some other. There are many sources that produce chlorofluorocarbons that are created by human beings or are utilized by humans such as refrigerators, aircraft and many more.

It's have to be 12 or idk

That depends on what kind of environ meant it is in  in space it has the same force that was applied when the velocity was gained