So, I'm considering an Artsy Fartsy project with hard drive platters. Being mildly aware of the world around me, I've come to the conclusion that I probably shouldn't grind up modern (or any) electronics and drink it for tea. To that end, is there anything in hard drive platters that is significantly toxic, or are they fine lying around the house? I don't intend in grinding them or anything, I'll be using them whole, so dust inhalation presumably isn't a big issue.
I never opened a newer 2.5" hard disk, but I've read that these may contain glass platters.
However, I've seen and touched stacks of platters from old 3.5" hard disks - a friend of mine makes clocks from hard disk cases.
These platters have an aluminium core, on which another metallic layer, that serves as a kind of primer, and the magnetic material are applied by sputtering. The surface is covered by a protective polymer layer.
Platters have been drilled or cut in a lot of electronics projects, e.g. to make hdd clocks based on the persistence of vision effect. Apart from the usual safety rules for metal works (protect your eyes, don't touch the hot drill, etc.) one only has to make sure that the rotating platter is properly mounted and doesn't start flying around!
When the platters aren't mechanically altered and only painted, there is even less danger. The platters are not toxic and do not even have sharp corners - it is safe to keep them around in the living room.
On a side note, the magnets from these hard disks are more dangerous. These magnets are pretty strong and when playing with them, you can easily jam your fingers between them ;)
Discs from 3.5" drives are perfectly safe. They are made of a majority of aluminum, with hints of platinum, palladium, and other precious metals (not a lot though — the Pt coating is only a few atoms thick).
Stay away from 2.5" drives though. Their platters are made of some sort of glass, and if you put too much pressure on them, they will shatter with razor-sharp chunks of glass flying everywhere.
I think you're OK if they're just lying around.
Some drives, maybe only older ones, do contain nasty stuff such as beryllium, so I'd be wary of opening them up or crushing them in any way.