Been thinking about this because on the Oriskany we had miles of piping below decks and half the time you couldn't tell what was wrapped around it. That's the real problem with thermal lagging.
First off the stuff gets painted over. White paint, gray paint, whatever was on hand. You're looking at a pipe with what looks like regular insulation wrap and you have no idea if there's asbestos underneath because you can't see it. The paint seals it all in.
Second it degrades different ways. Some of it stays intact for decades and some of it starts cracking and flaking and nobody notices because it's behind equipment or in spaces you don't go into regularly. When it starts to deteriorate that's when the fibers get loose and that's when people breathe them in.
Third it looks exactly like non-asbestos lagging. There's no way to tell by looking. Could be asbestos, could be fiberglass, could be mineral wool. You need a lab test to know for sure. And back when they were installing this stuff on ships nobody was testing anything.
The Navy didn't document half of what was asbestos and what wasn't. They just used whatever was available and cheap. Thermal lagging was everywhere on the engineroom piping and the machinery spaces. You were working near it constantly and you had no way to know.
That's what gets me about the whole thing. They knew but they didn't tell us.