(Jeff B, Gerardo M)
Found some goop on the cleanroom curtains, yes the cleanroom over HAM1-HAM2.
The goop appears to be generated from a reaction between the glue of the tape and the vinyl of the curtain, so far the reaction does not appear to take place on "ameristat", we will look further into that.
Note: on photos attached only look at curtain content.
Years ago, the cleaning crew were wiping down these curtains with some sort of solvent (Acetone?) which caused similar issues. Could this be happening again?