Deutsche Gesellschaft für
Technische Zusammenarbeit (GTZ) GmbH
Convention Project Chemical Safety
33
Use all 3 factors to identify the
appropriate Control Approach
Control Level 1
A good standard of general ventilation & good working practices
Control Level 2
Engineering control, e.g. local exhaust ventilation ranging from a single
      point extract close to source of hazard to a ventilated partial enclosure
Control Level 3
The hazard should be contained/enclosed
Control Level 4
Expert advice is needed to choose the necessary control measures