The interior of the Isolator is kept at a lower pressure than its surroundings to prevent the outflow of harmful materials while the working space is bathed in a down-flow of sterile air.  

Operator access to the Isolator is by means of gloves mounted in the front viewing screen. These can either be full arm gauntlets or sleeve pieces with rigid cuffs to allow the use of different types of gloves and to facilitate rapid and economical replacement in the event of damage.  

Materials may be introduced or removed via the ventilated transfer hatches, usually one on each side of the isolator. The transfer hatches have electrically interlocked hinged doors preventing both doors being opened at the same time; this prevents any room air entering the main work zone. 

Air from the room passes through HEPA filters mounted on the top of the transfer hatches, from each transfer hatch the air then flows through rear wall HEPA filters and passes into a rear plenum. This then mixes with air from the work area, passing through work zone HEPA filters mounted in the rear wall of the isolator body, part of the air is re-circulated through down-flow HEPA filters and the remainder of the air is returned to the room via the recirculation module containing double HEPA filters or alternatively if the isolator is a ducted model the air will be vented through a dedicated extract system to atmosphere.