Which type of enteral system has higher contamination risk due to nursing manipulation when adding formula to the bag?

• A. Closed System
• B. Semi-Closed System
• C. None of the Above
• D. Open System

Answer: (D)

The key idea is that contamination risk rises when sterile contents are exposed to the environment during handling. In an open system, adding formula to the bag requires opening the bag and pouring into it, exposing the contents to air and surfaces. This creates the greatest opportunity for bacteria to enter the system. A semi-closed system reduces exposure by using a port or controlled access for adding formula, which lowers the risk compared with an open setup. A closed system keeps the contents prefilled and connected with minimal handling, offering the least opportunity for contamination. Therefore, when formula must be added to the bag, the open system carries the highest contamination risk due to the nursing manipulation involved.