BiopharmaceuticalManufacturing

InstrumentClassification

Instrument ClassificationAnd

Identification

For biopharmaceutical applications, instruments are generally classified as critical or non-critical, with some

organizations allowing for a third classification, diagnostic or reference.

Please note: The author does not advocate the use of the

diagnostic or reference designations. The concept of an instrument that is not ever

calibrated, violates any concept of good engineering or maintenance practices.

Every instrument in a facility should be identified as one of these

classifications. Generally, instruments classified as critical are calibrated typically on a quarterly schedule, those classified as non-critical are typically calibrated annually. The diagnostic instruments are not

calibrated regularly.

The definitions of the various classifications are not totally objective. They usually have to allow for some

judgment in assigning the criticality of the device. For example, following are typical definitions used to distinguish

between critical and non-critical instruments.

Critical Instrument: A process instrument, the failure or

incorrect calibration of which can create an immediate

negative impact on product quality.

Non-Critical Instrument: A process instrument, the failure or incorrect calibration of which may impact a secondary processing

system or anon-quality related parameter of

the process.

Note that there is a lot of room for maneuvering.

Since these definitions have to apply to many different systems,

they cannot be exact. Judgment is required, and wisdom to err on the

conservative side.

Examples of critical instruments would be temperature recorders on hot Water-For-Injection (WFI) or steam sanitized USP Purified

Water systems.

Examples of non-critical instruments could be a pressure gauge on a

compressed air line for a line supplying air to a pressure

reducer.

Identification means each instrument must have a unique

identifying designation. This identification will remain with the instrument throughout its life and allow for proper scheduling and repair record. The designation system is usually defined in the Standard Operating Procedure

(SOP) for the Calibration System.