If the laminar hood is turned off, how long must it be turned back on before use?

The laminar flow hood is a critical piece of equipment used in pharmacy compounding, particularly for sterile preparations. When the hood is turned off, the airflow and filtration systems that maintain a sterile environment are compromised. The air in the hood can become contaminated, posing risks to the integrity of the compounds being prepared.

A laminar flow hood needs to run for a sufficient period upon being turned back on to flush out any potentially contaminated air and to ensure that the environment is properly sterile and safe for compounding. The recommended time for the laminar flow hood to be running before use is typically around 30 minutes. This allows the systems to adequately filter and circulate air, therefore re-establishing the sterility of the workspace.

In practice, this is a safety measure to protect both the pharmacy technician and the patients who will receive the compounded medications. Thus, turning the laminar hood back on for 30 minutes before use helps ensure that the environment has been sufficiently cleared of contaminants and is safe for sterile compounding.