I used to do the same thing as @bdm105 and keep them on the shelves with the rest of my records. I then noticed an outer sleeve on a record that was next to a record with a PVC sleeve (mind you, with a poly outer guard surrounding the PVC) was showing signs of off-gassing. I now put any records in a PVC in regular poly sleeves and store the PVC sleeves separate from my collection.
I might start doing the same as the above - I've noticed the horrible PVC smell in the inner sleeve so I'm gonna put it through the Humminguru again and store the PVC sleeve somewhere else... Thanks for the comments all
Yeah I've got a Bowie EMI reissue which is just such a nice package including a stickered thick PVC outer and it sucks because I really want to store them together but I can't risk it. It has been banished to where all unwanted inners and outers go to die, in a big pile underneath the bed in my guest bedroom.
To be fair, I treat my exiled PVC with a little more dignity and keep them in a record mailer on a shelf in my office. "Underneath the bed in my guest bedroom" really just sounds like the vinyl equivalent of a murder dungeon.