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PDA Technical Glossary

PDA Technical Reports are highly valued membership benefits because they offer expert guidance and opinions on important scientific and regulatory topics and are used as essential references by industry and regulatory authorities around the world. These reports include terms which explain the material and enhance the reader’s understanding.

The database presented here includes the glossary terms from all current technical reports. The database is searchable by keyword, topic, or by technical report. Each definition provided includes a link to the source technical report within the PDA Technical Report Portal.

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F-Value (Lethality Factor) -- FO

A term used when the specific reference conditions of Tref = 121.1°C and z = 10°C are used to calculate the equivalent lethality. For example, when the z-value of the BI is 10°C a cycle with an F(T=121.1°C, z=10°C), or F0, equal to 8 minutes is equivalent (in terms of delivered lethality) to a square wave cycle of 8 minutes at 121.1°C. A square wave cycle that provided an exposure of 25.9 minutes at 160deg;C would also yield an F0 of 8 minutes. (TR1)

Source: TR 1: Validation: Moist Heat

Manufacturing GMP/Good Manufacturing Processes/cGMP Microbiology Validation Sterile Processing

F-Value (Lethality Factor) -- FBiological

A term used to describe the delivered lethality, measured in terms of actual kill of microorganisms on or in a BI challenge system. The FBiological-value is calculated as DT × LR, where DT is the D-value of the BI system at the reference temperature (T) and LR is the actual logarithmic reduction (log N0 – log NF) of the BI population achieved during the cycle. (TR1)

Source: TR 1: Validation: Moist Heat

Manufacturing GMP/Good Manufacturing Processes/cGMP Microbiology Validation Sterile Processing

F-Value (Lethality Factor)-- FH

A term used when the specific reference conditions of Tref = 160°C and z=20°C are used to calculate the equivalent lethality. For example, when the z-value of the BI is 20°C a process with an F(T=160°C, z=20°C), or FH, equal to 8 minutes is equivalent (in terms of delivered lethality) to a square wave process of 8 minutes at 160°C. A square wave process that provided an exposure of 45.2 minutes at 145°C would also yield an FH of 8 minutes. (TR3)

Source: TR 3: Validation: Dry Heat

Manufacturing GMP/Good Manufacturing Processes/cGMP Microbiology Validation Sterile Processing

Free Drained Equipment

No visible water pool in the equipment or line when viewed under appropriate lighting conditions (but may contain water droplets). (TR29)

Source: TR 29: Validation: Cleaning

Biotechnology Manufacturing Microbiology Validation Quality Risk Management/QRM Sterile Processing

F-Value (Lethality Factor) -- Fphysical

A term used to describe the delivered lethality calculated based on the physical parameters of the cycle. The FPhysical-value is the integration of the lethal rate (L) over time. The lethal rate is calculated for a reference temperature (Tref-) and z-value using the equation: L = 10(T-Tref- )/z. (TR1)

Source: TR 1: Validation: Moist Heat

Manufacturing GMP/Good Manufacturing Processes/cGMP Microbiology Validation Sterile Processing

F-Value (Lethality Factor)

A measurement of sterilization effectiveness, the F-value is the calculated equivalent lethality (using a specified z-value), in terms of minutes at a reference temperature (Tref), delivered by a sterilization cycle. (TR1) (TR3) (TR30) (TR48) (TR61)

Source: TR 1: Validation: Moist Heat

Manufacturing GMP/Good Manufacturing Processes/cGMP Microbiology Validation Sterile Processing

False Positive

A test result that is erroneously classified in a positive category (e.g., a viable microbial detection result when viable microorganisms are not present). (TR33)

Source: TR 33: Rapid Micro Methods

Biotechnology Manufacturing Microbiology Validation Sterile Processing Technology Transfer

False Negative

A test result that is erroneously classified in a negative category (e.g., the absence of a viable microbial detection result when viable microorganisms are present). (TR33)

Source: TR 33: Rapid Micro Methods

Biotechnology Manufacturing Microbiology Validation Sterile Processing Technology Transfer

First Air

Refers to the air exiting at the face of HEPA filters. Based on the airflow through HEPA filters and its unidirectional air flow the air exiting at the filter face is for the purposed of aseptic processing free of particulate contamination (both viable and non-viable). (TR70)

Source: TR 70: Cleaning/Disinfection Programs

Biotechnology Manufacturing GMP/Good Manufacturing Processes/cGMP Microbiology Validation Quality Risk Management/QRM Sterile Processing

Fraction-Negative Methods

Fraction-negative methods use the starting population of a biological indicator (N0) and data in the quantal range to create a two-point line from which the DT-value can be determined. The quantal range is the exposure period over which a set of replicate test units exhibit a dichotomous response – some are positive for growth and the rest are negative for growth. (TR01)

Source: TR 1: Validation: Moist Heat

Manufacturing Microbiology Validation Sterile Processing

First Air (First Work Location)

The work location first in the path of HEPA filtered air. (TR62)

Source: TR 62: Manual Aseptic Processes

Biotechnology Manufacturing GMP/Good Manufacturing Processes/cGMP Microbiology Validation Quality Risk Management/QRM Sterile Processing

Focus Forming Unit (FFU)

A measure of virus infectively based on formation of a region or “focus”, of infected cells within a monolayer culture that is caused by viruses that do not kill their host, but rather transform them. The number of foci is directly correlated to the number of infectious virus particles. (TR47)

Source: TR 47: Virus Spikes/Virus Clearance

Virus Biotechnology Manufacturing Microbiology Validation Sterile Processing