2.3 Segregated Compounding Areas (SCAs) & Containment SCAs (C-SCAs)

Concept and Role of the Segregated Compounding Area

Not every healthcare setting—such as satellite clinic pharmacies, ambulatory surgical centers, rural critical access hospitals, or oncology infusion suites—possesses the physical footprint or capital resources to construct a full ISO Class 7 cleanroom suite. To accommodate these practice sites, USP General Chapter <797> permits the placement of an ISO Class 5 Primary Engineering Control inside an unclassified space designated as a Segregated Compounding Area (SCA).

Strict Operational Trade-Off: Category 1 Beyond-Use Dates

Because the air surrounding the PEC in an SCA is unclassified (containing millions of particles and variable microbial bioburden per cubic meter), transient turbulence from walking personnel can occasionally compromise the cabinet's air barrier. Consequently, all preparations compounded in an SCA are classified as Category 1 CSPs:

• Controlled Room Temperature: Maximum BUD of 12 hours.
• Refrigerated Storage ($2^\circ\text{C}$ to $8^\circ\text{C}$): Maximum BUD of 24 hours.
• Frozen Storage: PROHIBITED. Category 1 CSPs cannot be frozen to extend their BUD.

SCA Facility Requirements (Non-Hazardous)

An SCA used for non-hazardous sterile compounding must meet strict structural criteria:

1. Defined Perimeter: The SCA must be a designated space with defined physical boundaries (walls and doors) or a visibly demarcated perimeter.
2. No Unsealed Exterior Penetrations: The SCA must not contain unsealed windows or doors opening directly to the building exterior.
3. Proximity Restrictions: The SCA must be located away from high-traffic hospital corridors, construction, restrooms, warehouse receiving bays, and cafeteria food preparation areas.
4. Plumbing Proximity: The hand-washing sink must be at least 1 meter (about 3.3 feet) from the PEC. It may be either inside the SCA or in close proximity to it.

Containment Segregated Compounding Areas (C-SCAs) under USP <800>

When a facility compounds sterile hazardous drugs (such as antineoplastic chemotherapy agents) without a full cleanroom suite, it must construct a Containment Segregated Compounding Area (C-SCA) under USP <800>.

Mandatory Engineering Specifications for C-SCAs

Unlike non-hazardous SCAs (which can be open areas with marked perimeters), a C-SCA must meet rigid containment mandates:

• Fixed Physical Walls and Doors: A C-SCA must be a fully enclosed room separated from surrounding areas by full-height walls and self-closing doors.
• Negative Air Pressure: The C-SCA must maintain continuous negative pressure relative to all adjacent unclassified spaces of -0.010 to -0.030 inches of water column ($-2.5\,\text{Pa}$ to $-7.5\,\text{Pa}$) to prevent hazardous vapors from leaking into surrounding clinic spaces.
• Air Exchange Rate: Must provide a minimum of 12 Air Changes Per Hour (ACPH).
• External Venting: The C-SCA must be externally vented, and the C-PEC used for sterile HDs (Class II BSC or CACI) must also be externally vented.
• Sink Distance: The hand-washing sink must be at least 1 meter from the C-PEC and may be either inside the C-SCA or directly outside it.

Master Comparative Architecture: Non-Hazardous SCA vs. C-SCA vs. Cleanroom Suite

Operational Decision Workflow and Category 1 Quality Management

Operating an SCA or C-SCA requires rigorous scheduling to avoid administering expired preparations. Pharmacists must integrate compounding schedules with nursing infusion times:

1. Just-In-Time Compounding: Category 1 CSPs should be compounded close to administration. The BUD marks the time after which a CSP must not be used, stored or transported. Many facilities therefore time preparation so that even a long infusion (for example, one running 6 hours) finishes before the 12-hour room-temperature limit.
2. Labeling Precision: Labels on Category 1 CSPs must clearly display both the date and the exact hour and minute of expiration (e.g., 'Discard after: 2026-09-29 at 18:30').
3. Environmental Monitoring: USP <797> sampling targets classified air, which in an SCA means the ISO Class 5 PEC. That requires viable air sampling at least every 6 months and surface sampling at least monthly. The Table 10 cleaning frequencies apply to every surface inside the SCA perimeter except the ceiling, which is cleaned when visibly soiled or when contamination is known or suspected.