looks like paint
 

Typical poltergeist activity. I'd quickly hire an exorcist or a team of quirky ghostbusters.

Looks like paint, possibly it is peeling due to the ceiling drywall being saturated with moisture. This, in turn, may be because the bathroom exhaust fan duct was not vented to the outside of the house.

paint

if the window is not insulated, the constant thermal cycling is probably flaking the non-mfr-applied finish (paint)

or the moisture thing above

Im going guess poltergeist too. In the paint though. That is why it peeled in such a manner.

which csi section would you put poltergeist under?

Plaster smooth trowel; painted.  Too much moisture.  Use a polymer infused plastic, 1/8" min joints at abutments, and maybe an epoxy coating next round.

It falls under Extraterrestrial/Supernatural Events...Chp 18.

In all seriousness just looks like paint peeling. Use a metal scraper to remove all the loose debris, and then sand with a 220 grit or whatever. There shouldnt be any asbestoses in it, but if you are concerned there are labs that will test it. Probably may have lead, those lab test can be found at Ace hardware and the like. 

Killz makes this white primer paint that has a hardener in it that cures the latex much stronger. Anyone that works at the paint department should be able to help!

I'm not so sure about specifying a poltergeist. Seems like it would be a horrible product of the contractor's failed responsibilities related to jobsite and worker safety. 

However, managing the poltergeist once you have one would logically fall into section 10 81 21, "Poltergeist Control Devices." Make sure you specify a good warranty. 

Note: In my exceptionally recent experience (yesterday), Kilz Primer did not work. I had to use Zinser BIN Primer, which worked flawlessly.

Note: This was for grease staining. Or possible 30 year old tobacco juice. Don't know how either would perform for poltergeists.

I have to admit I'm also confused: Is the WALL circular, or is the wall a flat plane* that has a circular opening cut into it?

* as near to truly flat as a physical plane can be in this non-physical experience of one multi-verse, of course.

I prefer the classics against poltergeists: 4 coats of Lead-based paint. If you want to be extra careful, you could always place lead sheets between the studs but now-a-days, it's considered overkill.

lol, Donna you are right... I went and looked at what I use and it is Zinser's Primer. It is right next to the Killz at lowes, and killz is kinda crap as noted. The Zinser primer is amazingly good and coating and dries super hard. It has done a number on my wagner sprayer though... def isn't your normal latex paint.

op said 1989-1990

i believe lead paint was banned from household paint in 1978.

according to wikipedia, 1989 was the year the following was released:

The Exorcist III

Amityville 4: The Evil Escapes

Halloween 5: The Revenge of Michael Myers

A Nightmare on Elm Street 5: The Dream Child

Friday the 13th Part VIII: Jason Takes Manhattan

the forensic architect in me says ghosts are far more likely than lead.

A tin foil helmet provides superior protection against poltergeists.

To the OP, it's clearly asbestos, probably with a radon based adhesive. Call the EPA and DEC immediately.

they quit putting carbon monoxide in residential paints before 1989 too.

however you'll still find paints with significant amounts of dihydrogen monoxide.  the dangers of that shit have been clearly documented but regulators have been slow to respond.  the op is obviously not in california, where they have more stringent environmental regulations.

All kidding aside, DHMO is very dangerous. Check http://www.dhmo.org/ for more info.

Curt, dihydrogen monoxide is evil. I can't believe they still allow that stuff without the proper labelling. People should know what toxins they put in their bodies!.

I would  first  go get the most expensive  chemical  based stripper product which is not GREEN.

Then  bring it home strip down  naked and  grab a paint brush.  Close up the space as tightly as possible.  Pour the stuff into a  styro-foam container then take your paint brush and cover every square inch of the area where the peeling is occurring, when your done go sit in the corner and smoke a dubbie.  Cause you don't want to leave the room, you watch it bubble for a half and hour then go after it with a number 11 X-ato knife blade.  Just keep breathing deeply until you see the  poltergeist lift right out of the floor.  It happens every time.  When you have put it all into a plastic bag be sure to dump it into a garbage pick up dumpster cause you don't want anyone to know you  have been messing with lead based paint.  Oh wait before you put it in the dumpster take the bag stick your head into it and get a couple of good blast.  If you see the poltergeist in the bag you know you have all of them.  Then try to find the back door to your house, hopefully by morning you will be able to do so.  Give it a day and go back and do it again just for good cause, you never know when one of those guys is going to escape  the old X-ato knife.  A couple days later go roll another dubbie,  light it up and go paint the crap out of it with Zinser BIN Primer, not  Killz will because the stuff will Kill you.  In a weeks time if the neighbors are looking at you kinda strange it is because they saw you walking around naked with plastic garbage bags in the middle of the night on two occasions.

^ That's doobie, as in The Doobie Brothers.

snook you're killing me hahahaha! This thread is gold. Not lead, gold, unless you're an alchemist. But if you're an alchemist the poltergeists won't stick around anyway.

Donna...my pleasure... if it didn't  happen in studio...you wouldn't believe it...lol