Howorth Pharma downflow booths achieve 1µg/m3 containment
Since Howorth Pharma introduced its first downflow booth to feature the exclusive new cGMP-design High Containment Screen in 2006, it has proved extremely popular, the company says. Including the screen takes conventional booth performance to a guaranteed level of less than 10µg/m3 of air in the safe working zone, with levels less than 1µg/m3 independently validated in practice.
The rigid, transparent screen is made from toughened glass. It slides along a cGMP wall-mounted tubular rail and is manoeuvred without difficulty by the operators, allowing them to move along the working area without removing their arms from the integral glove ports. Operations such as scooping from a drum, weighing, dispensing and sampling are thus easily accomplished. This innovation provides maximum security with minimal operator restriction. When not needed for any length of time, the screen can be easily removed and stored.
The design of the High Containment Screen offers five main advantages over traditional flexible curtains:
- Curtains tend to be full length and gather around the floor, creating eddies as the air is directed around them. The High Containment Screen stops 500mm short of the floor so airflow is not disturbed. Airflow is directed under the screen towards the rear exhaust plenum, and not towards the operator's breathing zone
- Plastic can become increasingly opaque due to solvent wash. However, glass does not discolour with use, so vision remains clear
- Curtains are difficult to clean due to folds in the fabric, but the rigid screens are a highly cleanable cGMP design and can simply be wiped or sprayed in position
- Unlike plastic curtains, glass does not attract static build-up
- Customer feedback from user-groups indicates that the High Containment Screen is considered to be more user-friendly than flexible screens.