Which is the first area to clean in a Primary Engineering Control (PEC)?

In a Primary Engineering Control (PEC), the first area to clean is the floor of the hood. This is important because the floor accumulates the most debris and particulate matter, which can easily be disturbed when cleaning other surfaces. By starting at the bottom and working upwards, the risk of contaminants falling onto cleaned surfaces is minimized. Cleaning the floor first establishes a baseline for cleanliness in the PEC, allowing for more effective cleaning of surfaces like countertops and walls thereafter. This also follows a logical sequence that helps to maintain a controlled environment where aseptic techniques are paramount in compounding sterile preparations.