Paul,
you are talking about urban hunting, correct? "target" = "quarry", right?

OK, if you
(1) miss your quarry, and
(2) hit some kind of backstop (fence, tree, etc.) —
it seems you should be fine (unless you shoot in an environment that is golfball like.... — remember the shoot-a-golfball YouTube vids where people got ricocheted, even 70 and 100y away....).

However, if you
(1) miss your quarry, and
(2) don't hit any kind of backstop — e.g., when taking an angled shot into the trees) —
you might not be fine in an urban hunting context —
because the slug has a hugely better BC in comparison to any kind of pellet, and will therefore fly on for two, three or more times the maximum range of a pellet.

The link below gives some data on the
maximum dangerous range of various pellets and slugs for angled shots:
https://www.airgunnation.com/topic/pellets-drop-down-from-the-sky/#post-636617 Matthias