Use & Maintenance of Engineering Controls

VTH Policy # PharmH663

Implementation Date: 11/2021

Date of Last Review: 7/9/2023

Next Review Due: 7/8/2026


Reviewed by VTH Administrative Team: 11/2021

Reviewed by VTH Board: N/A


Reviewed & Approved by Hospital Director: 11/2021 

Reviewed by Biosecurity Subcommittee: N/A

Subject to modification by the VTH Director without approval.


The intent of this policy is to define the use and maintenance of engineering controls to ensure personnel and environmental safety.

Personnel must consistently use engineering controls and appropriate personal protective equipment (PPE) when handling hazardous drugs (HDs) to minimize the risk of occupational exposure. Engineering controls will be evaluated and maintained and closed system transfer devices (CSTD) will be stocked and readily available.


  • Engineering controls are required to protect the preparation from cross-contamination and microbial contamination during all phases of the compounding process. Engineering controls for containment are divided into three categories representing primary, secondary, and supplementary levels of control.
    1. Primary: The primary engineering control (C-PEC) is a ventilated device – a biosafety cabinet or hood – designed to minimize worker and environmental HD exposure when directly handling HDs.
    2. Secondary: The secondary engineering control (C-SEC) is the room in which the C-PEC is placed that has appropriate airflow (positive/negative pressure) and air changes per hour (ACPH).
    3. Supplementary: An example of a supplementary engineering control is a closed-system drug transfer device.

  • Sterile HDs must be compounded within a C-PEC located in a C-SEC. The C-PEC must be externally vented, and the C-SEC used for sterile and nonsterile compounding must:
    1. Be externally vented via a HEPA filter
    2. Be physically separated from other preparation areas (e.g., in a different room from other activities)
    3. Have an appropriate air exchange denoted as air changes per hour (ACPH).
      • 30 ACPH for sterile HD compounding
    4. Have a negative pressure between 0.01 and 0.03 inches of water column relative to all adjacent areas


  • Non-sterile HDs should be compounded within a C-PEC located in a C-SEC
    • One exception to this is when an FDA-approved manufactured dosage form is utilized instead of an active pharmaceutical ingredient (API) or bulk chemical


  • Appropriate PPE must still be worn when preparing the non-sterile compound


  • For C-PEC where non-sterile HDs are prepared, the C-PEC should have vertical airflow and 12 ACPH


  • A sink must be available for hand washing and an eyewash station and/or other emergency or safety precautions must be readily available.
    • Per hospital policy, a safety shower must be available for use.


  • Containment Supplemental engineering controls, such as CSTDs must not be used as a substitute for a C-PEC when compounding. CSTDs should be used when compounding HDs when the dosage form allows. CSTDs must be used when administering antineoplastic HDs when the dosage form allows. CSTDs known to be physically or chemically incompatible with a specific HD must not be used for that HD.


  • Dedicated personnel will verify and document that all engineering controls are in proper operating condition.  This will be facilitated through the VTH Facilities group.
    • Dispensary staff will monitor temperature, humidity, pressures, out-of-range notifications, and alarms and will report any changes to facilities.

Procedure (if applicable)


Definitions (if applicable)

Veterinary Teaching Hospital (VTH): The collective clinical services of the Large Animal Clinic, Midwest Equine, the Small Animal Clinic, and the Veterinary Medicine South Clinic.



Keywords:engineering controls, cleanroom, hood, biosafety cabinet   Doc ID:129778
Owner:Jenny C.Group:University of Illinois College of Veterinary Medicine Teaching Hospital
Created:2023-07-17 13:56 CDTUpdated:2023-07-17 15:31 CDT
Sites:University of Illinois College of Veterinary Medicine Teaching Hospital
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