Maintaining control of environmental conditions is crucial in a compounding pharmacy. All personnel who compound or supervise compounding personnel must undergo initial training and demonstrate competency in compounding sterile preparations and achieving and maintaining appropriate environmental conditions.

USP 797 classifies compounding sterile preparations (CSPs) into three categories based on the level of environmental control during compounding, the likelihood of microbial growth during storage, and the duration within which they must be used.

Category 1: Compounded under the least controlled environmental conditions. These preparations may be prepared in a Primary Engineering Control (PEC) located in an unclassified segregated compounding area. They are assigned a BUD (beyond-use date) of ≤ 12 hours at controlled room temperature or ≤ 24 hours when refrigerated.

Category 2: Require more environmental controls and testing than Category 1. These preparations must be prepared in a cleanroom suite. They may be assigned a BUD of > 12 hours at controlled room temperature or > 24 hours if refrigerated.

Category 3: Undergo sterility testing, supplemented by endotoxin testing when applicable, and have more requirements than Category 2 CSPs for personnel qualification, use of sterile garb, use of sporicidal disinfectants, frequency of environmental monitoring, and stability determination. They have additional requirements that must be met at all times. These preparations may be assigned a BUD longer than established for Category 2 CSPs, up to 180 days.

Before beginning to compound Category 1, 2, or 3 CSPs, personnel are required to successfully complete 3 separate evaluations in succession for hand hygiene, garbing, gloved fingertip and thumb sampling, media fill, and surface sampling.

USP 797 – Personnel Qualification and Environmental Monitoring Requirements (after successful completion of initial competency)