irreversible consequence

A consequence that cannot be reversed.

Some consequences are evitable, such as preventing or reducing the extent of an injury by wearing a seat-belt, or preventing a pregnancy by using a condom.

However, other consequences are inevitable, such as being disliked after saying something offensive.

And an irreversible consequence is one no one can go back in time and prevent from taking place because the action which produced it was executed.

The only way to prevent any type of consequence is by not executing an action (known to produce certain types of consequences).

Nonetheless, not doing anything might also generate some type of foreseeable or unforeseeable consequence.