Containment is the separation of a hazardous area from a clean area with a barrier.
For potent containment, the barrier protects the personnel & environment from the product. For sterile containment it’s the opposite.
Of course personal protection is critical for human health. Every employer wants to avoid staff exposure to hazardous substances. So when handling potent compounds, containment strategies must be put in place so that the exposure of the operators to the APIs is minimized and kept below the safety limits. And this can be achieved by means of physical barriers (isolators) or aerodynamics (downflow booths).
For sterile applications, like injectables only containment and sterilization processes can significantly reduce the exposure of the products to the contaminated environments and can guarantee in the end the safety of the finished product.
Now in reality, exposure cannot be reduced by equipment alone: proper SOPs (Standard Operating Procedures) must be developed and strictly followed.
Finally testing is very important. First the equipment must be validated after the installation to guarantee that the exposure is kept below a safe limit. Then, once up & running, regular testing is essential to continuously monitor the equipment performance.