I took some particle counter measurements in B102 and some LIGO optics labs in Lauritsen. x/x/x is the 0.3 um, 0.5 um, and 1.0 um cumulative count over 1 minute.

B102:

77973/4322/471 before fans were turned on. The fans were left off over the weekend.

9/0/0 after the fans were on for 90 seconds before starting the count

LIGO clean room to measure the scatter off of our optics, including the super-polished optics:

1/0/0 near curtains

0/0/0 2 feet inside curtains

Room with Fizeau Interferometer

84868/3495/397

GariLynn Billingsley says they clean the LIGO test masses a lot after they are in this room, but this is definitely not a clean room