Is this asbestos pipe insulation
It does not look like typical fiberglass. The era is right. Testing and reasonable care is certainly advisable, as is a reminder that most &quot;effects of asbestos exposure&quot; are from chronic exposure (folks that worked with the stuff) not whatever tiny bit you may have been exposed to in ripping one or two pipes open before going: Hmm, this doesn't look like what I was expecting.
The only way to know for sure is to have it tested at a lab (if you get exorbitant prices and scare tactics, keep shopping for a reasonable lab.)