Board Thread:Naruto Discussions/@comment-25691159-20200529162803/@comment-9782468-20200530223801

"They stopped spreading because they burned up"

So they're not eternal are they? lmao

"If the author calls them eternal"

He also said they burned for 7 days and nights lol

If it wasn't relevant to list in the manga why should they?

Amaterasu is inextinguishable by conventional methods. But it has been sealed, absorbed, nullified, dodged, and simply left behind.

Yes, the flames go out on the 7th day or when the target is incinerated.