Well I've never had anything life threatening but i've burned, sliced, scraped, scuffed, pierced, and shaved skin.
Tips:
(1) never use a razor without a holder (slippage sucks)
(2) wear the goggles! (almost lost an eye)
(3) never look away (couldn't use my hand for over a month)
(4) use clamps (you'll slice your hand right open)