 As such, the term "negative pressure" isolator is somewhat of a misnomer, as contaminated ("polluted") room air must not be pulled into the main workstation isolator in a sterile operation.Thus, the actual workstation isolator is always maintained under substantial positive pressure.The "negative" pressure isolator does however include a separate buffer zone (an extra isolator compartment) that is designed to exhaust both incoming room air and outgoing positive pressure air from the main workstation.