Just had an "interesting" experience with an old 250 ml tin of this.
The tin was apparently manufactured in July 99, and had been stored for most of that time in an attached garage. For the last several months it had been stored in a kitchen, but not exposed to high temperatures. On gently levering the top with a screwdriver blade, as soon as it became slightly loose it blew off with a loud bang, hitting the ceiling and spraying a little of the PVA liquid around the place (fortunately it just missed my eye). There was no indication at all that it was under high pressure.
The tin was still about 3/4 full, didn't smell unusual, and the glue worked ok on some wood I needed to stick.
Anyone else had a similar experience with this (or another) PVA product?