Stationary fume extractors must discharge the exhaust air to the open air. Mobile fume extractors with appropriate filters for the pollutants in question shall be used where the use of stationary fume extractors is impracticable. The exhaust air from fume extractors with filters may not be discharged to confined spaces.Rooms in which work with cytostatics is carried out must be provided with worktops with fume hoods. The fume hoods must have transparent sashes. Such rooms must have separate ventilation, and the exhaust air must be routed to the open air, either directly or after being cleaned as necessary.