USP 797 Garbing and Donning Requirements: Current Standards and Best Practices

USP 797 requires compounding personnel to wear cleanroom apparel that minimizes the release of particles and microorganisms. Garbing must be performed in a defined order, progressing from lower to higher cleanliness to avoid introducing contamination into the buffer area or primary engineering controls (PECs).

Garments must be clean, low-linting, non-shedding, and fully cover exposed skin and hair. Hand hygiene and routine glove disinfection are emphasized as ongoing practices, not one-time steps. Facilities are expected to establish written gowning procedures and ensure staff are trained and assessed for compliance.

Garbing Requirements in the Ante-Area

Garbing begins in the ante-area, which is typically classified as ISO Class 7 or 8, depending on the facility design. Before entering the buffer area, personnel must don foundational protective apparel and perform proper hand hygiene.

Required ante-area garb includes shoe covers or dedicated cleanroom shoes, a head cover that thoroughly covers the scalp, beard covers, if applicable, and a face mask covering the nose and mouth. Jewelry, cosmetics, artificial nails, and nail polish are prohibited due to their potential to shed particles or harbor microorganisms. After donning initial garb, personnel must thoroughly wash their hands and forearms with soap and water.

Buffer Area Garbing and Gowning Expectations

Once in the buffer area, which is maintained at ISO Class 7 or cleaner, additional garbing is required to reduce contamination risk further. Personnel must wear a cleanroom gown or coverall that thoroughly covers the arms and torso and fits securely at the wrists and neckline.

Sterile gloves are required for all sterile compounding activities. Gloves must be disinfected with sterile 70% isopropyl alcohol (IPA) before entering the PEC and intermittently throughout compounding. USP 797 requires IPA to fully air dry before aseptic manipulations resume to ensure effective microbial kill.

While previous versions of USP 797 emphasized sterile gowns and sleeves, the current standard no longer universally mandates sterile garments for all sterile compounding. Instead, gowning requirements are risk-based and tied to cleanroom classification and compounding activities. Many facilities continue to use sterile gowns as a best practice, even when not explicitly required.

ISO Class 5 Compounding Considerations

ISO Class 5 environments, such as laminar airflow workbenches, biological safety cabinets, and aseptic isolators, demand the highest level of contamination control. Within these environments, sterile gloves are mandatory and must be routinely disinfected throughout compounding.

Gloves must be sanitized after contact with non-sterile surfaces and replaced if torn, visibly soiled, or compromised. Disinfection alone is not sufficient when glove integrity is in question. Maintaining proper airflow and minimizing unnecessary movement within the PEC are also essential to preserving ISO Class 5 conditions.

Recommended Donning Sequence

USP 797 does not prescribe a single mandatory gowning order, but it does require that garbing proceed in a manner that prevents contamination. Most facilities follow a standardized sequence that begins in the ante-area and concludes in the buffer area:

• Shoe covers
• Head and beard covers
• Face mask
• Hand and forearm hygiene
• Gown or coverall
• Sterile gloves, followed by IPA disinfection

Garment Use, Reuse, and Disposal

Disposable garb must be discarded after each compounding session or upon exiting the classified space. Reusable garments may be used only if they are properly laundered by a qualified cleanroom laundry service and stored to prevent recontamination.

Any garment or glove that comes into contact with a non-sterile surface must be evaluated for contamination risk and replaced or disinfected as appropriate. Facilities should document policies governing garment reuse, disposal, and inspection.

Special Considerations for Isolator-Based Compounding

USP 797 allows for modified garbing requirements when compounding is performed in compliant compounding aseptic isolators (CAIs) or compounding aseptic containment isolators (CACIs). These allowances apply only when the isolator meets defined air quality and containment performance criteria.

Even in isolator-based workflows, sterile gloves are required for direct aseptic manipulation. Facilities must follow both USP requirements and manufacturer instructions, supported by documented risk assessments.

Supporting Compliance Through Consistent Garbing Practices

Proper garbing and donning are essential to achieving and maintaining compliance with USP 797. Current standards emphasize risk-based gowning, consistent hand hygiene, and routine glove disinfection as critical controls in sterile compounding environments. By implementing clear procedures, effectively training personnel, and regularly assessing compliance, pharmacies can reduce contamination risk and support safe patient outcomes in line with today’s USP 797 expectations. For those looking to strengthen their cleanroom programs, PAC’s cleanroom experts support compliance with USP 797, 795, and 800 and provide the full range of cleanroom apparel and PPE required to meet current regulatory expectations.