Compliance Testing USP 797

USP 797: Pharmaceutical Compounding – Sterile Preparations

Compliance Testing USP 797

Compliance Testing USP 797 – Sterile compounding procedures require clean facilities and compliance testing USP 797 to meet standards and specific training for operators, air quality evaluations, and a sound knowledge of sterilization and stability principles. The risk of contaminating a compounded sterile product is highly dependent on proper hand hygiene and garbing practices, compounding personnel aseptic technique, and the presence of surface contamination. Compliance Testing USP 797 provides guidelines, procedures and compliance requirements for compounding sterile preparations. The USP 797 sampling program and visual audit that Healthy Building Science provides is designed to evaluate the competency of work practices in accordance with the standard.

Compliance Testing USP 797 – Requirements

USP 797 refers to the United States Pharmacopeia (USP) chapter 797 “Pharmaceutical Compounding – Sterile Preparations,”  It is the first set of enforceable sterile compounding standards issued by (USP). Healthy Building Science inspectors will determine USP 797 conformance in 3 areas: Air Testing, Surface Testing, and Personnel Testing. If conformance standards are not met, Healthy Building Science will work with you to determine the source of the problem, eliminate the problem, and guide you towards compliance with the standard. 

Compliance Testing USP 797 – Data InterpretationCompliance Testing USP 797

Emlab P& K provided the following example of data interpretation “Data interpretation begins by comparing the results of nonviable and viable air particle testing and viable surface particle testing to the recommended action levels in USP <797>. These recommended action levels have been reproduced in Table 1 (9). If the number of particles detected by nonviable air particle testing, viable air particle testing or viable surface particle testing, exceeds the levels given in table 1, then it is necessary to begin a full root cause investigation of the source of contamination, followed by whatever steps are necessary to bring the particulate levels detected to within acceptable limits.


Table 1: Recommended Action Levels. (9)
ISO Class ≥ 0.5 µm Nonviable
Viable Airborne
Viable Surface
(cfu/contact plate)
5 3,520 > 1 > 3
7 352,000 > 10 > 5
8 3,520,000 > 100 > 100


For example, if a viable airborne particle sample from an ISO 7 clean room yielded a total of 11 cfu/m3, it would be higher than the recommended action level of greater than 10 cfu/m3and a full investigation into the source of contamination would be necessary. Alternatively, if the same sample had only 9 cfu/m3, the recommended action level would not have been exceeded and a full investigation would not need to be initiated. It is also necessary to implement an investigation and remediation in the event that there are particulates identified above historically detected levels for a given facility.

There is also a special requirement for viable air particle samples. If any cfu’s are detected on a viable airborne particle test plate from an ISO 5, 7 or 8 area, then USP <797> requires that the colonies growing on that plate be identified to at least the genus level, even if the number of colonies is below the recommended action level (10). The reasoning behind this requirement for genus identification is that there are some organisms that cannot be tolerated in a clinical environment at any concentration.”