Sampling room

In one of the site sampling rooms an issue regarding air flow requirements from the Hepa filter.

The room has 2 zones (a b), zone A is under the Hepa filter. in addition a 50cm Plastic sheets are been used around - marking the zone A area.
The Enterance to the room is also guarded with a long plastic sheets (to the floor).

can you please tell me the purpose of the plastic sheets and whether the length has a meaning ? ( i am considering shorthen the sheets)

Please advise,


Are the sampling rooms classed? ie ISO class 8 or 6? Is there only one entrance to this room?

Only one Entrance to this room, the room is class 8.