Medical Technology Associates: Pharmacy & Laboratory Service
Microbiological Monitoring
What is the USP 797 Compliance Standard for Non-Viable Particulates?
In critical areas, such as Class 100 or ISO 5 (area in immediate proximity of exposed sterilized containers/closures and filling/closing operations), the particle per cubic meter must be no more than 3520 particles/m3 in a size of 0.5 micrometers or larger when counted at representative locations normally not more than 1 foot away from the worksite, within the airflow, and during filling/closing operations. Supporting areas, or clean room areas where the laminar flow stations are located, must meet at least Class 100,000 (ISO 8) air quality. See table below.
| Clean Air Classification | ISO Designation | ≤ 0.5 µm particles/m3 |
| 100 | 5 | 3,520 |
| 1,000 | 6 | 35,200 |
| 10,000 | 7 | 352,000 |
| 100,000 | 8 | 3,520,000 |
What Type of Viable Sampling Do I Need to Perform for USP 797 Compliance?
You may need to take both air and surface samples depending on your situation. Impaction on a media plate is the preferred method for culturable air sampling. Settling plates, as suggested in earlier editions of USP 797, is specifically discouraged in the 2008 USP 797 guidelines. Surface sampling is required in all ISO-classified areas on a periodic basis. Surface sampling can be accomplished using contact plates and/or swabs. You must also regularly sample gear (clothing and gloves) of operating personnel. In addition, "media-fill tests" must be conducted at least annually by each person authorized to make sterile compounds to verify that they can do so aseptically.
How Do I Sample for Viable Particulates for USP 797 Compliance?
Air Sampling: Using an impaction sampler, collect as much air as possible without drying the media. The 2008 revision bulletin suggests a sampling volume of 400 to 1,000 liters of air, subject to recommendations by the manufacturer of the sampling device.