AS NZS 2243.9:2009 pdf free
AS NZS 2243.9:2009 pdf free.Safety in laboratories
The up-draught design is the most common type of recirculating fume cabinet because it is the simplest and most versatile design. The base unit is similar in design to a ducted fume cupboard; it has a head unit mounted on top of the base containing the pre-filters, main filter and the fan, which exhausts through the top of the unit (see Figure 1(a)). Operator access to the working chamber is through a transparent adjustable access window or sash which protects the operator from splashes during use and helps to keep the operator’ s face in a clean air zone.
An open-based recirculating fume cabinet is a variant of the up-draught design that permits location over existing services such as a laboratory bench, sink or gas outlet. The cabinet should be structurally strong and stable and should be carefully sited to ensure adequate performance.
A down-draught recirculating fume cabinet directs the airstream across or down through the base of the cabinet. This type of cabinet may be more suitable for applications where the fumes are denser than air (see Figure 1(b)).
Recirculating fume cabinets that are either portable or trolley-mounted need special consideration to prevent problems associated with the provision of services such as gas,water and electricity. Such problems include undue pressure on service lines and cables and access to drainage. Provision should be made to restrict the pressure that can be put on service lines. Trolley-mounted recirculating fume cabinets may be fitted with a sump that can be drained for disposal. When such a sump is fitted, the level of liquid in the sump shall be readily apparent to the operator and the recirculating fume cabinet shall display a warning label specify ing the spillage containment volume of the recirculating fume cabinet.AS NZS 2243.9 pdf free download.
