Final Answer:
The laminar airflow hood be on before being used for b) 30 minutes. (option b)
Step-by-step explanation:
A laminar airflow hood must be on for a minimum of ₃₀ minutes before being used. This time period allows the laminar airflow hood to establish a stable and controlled airflow within the workspace, ensuring the removal of contaminants and providing a sterile environment for procedures.
The 30-minute duration is a critical factor in maintaining the integrity of the laminar airflow. During this period, the hood reaches a steady-state condition where the air circulation pattern becomes consistent and meets the required cleanliness standards.
This waiting period is essential for laboratories, cleanrooms, or any environment where maintaining a sterile workspace is crucial for experiments, manufacturing, or other sensitive processes. It allows the laminar airflow hood to achieve optimal performance in creating a particle-free zone, minimizing the risk of contamination during work conducted within the hood.(option b)