Common Terms & Definitions used in Qualification & Validation of Heating, Ventilation and Air-Conditioning Systems for Non-Sterile Pharmaceutical Dosage forms.

Common Terms & Definitions used in Qualification & Validation of Heating, Ventilation and Air-Conditioning Systems For Non-Sterile Pharmaceutical Dosage Forms.


Design parameters should be set realistically for each project, with a view to creating a cost-effective design, yet still complying with all regulatory standards and ensuring that product quality and safety are not compromised. The three primary aspects addressed in this manual are the roles that the HVAC system plays in product protection, personnel protection and environmental protection.



 The definitions given below apply to terms used in these guidelines. They may have different meanings in other contexts.

Acceptance Criteria 

  • Measurable terms under which a test result will be considered acceptable.

Action Limit

  • The action limit is reached when the acceptance criteria of a critical parameter have been exceeded. Results outside these limits will require specified action and investigation.

 Air-Handling Unit (AHU)

  • The air-handling unit serves to condition the air and provide the required air movement within a facility.


  • An enclosed space with two or more doors, which is interposed between two or more -rooms, e.g. of differing classes of cleanliness, for the purpose of controlling the airflow between those rooms when they need to be entered. An airlock is designed for and used by either people or goods (PAL, personnel airlock; MAL, material airlock).

 Alert Limit

  • The alert limit is reached when the normal operating range of a critical parameter has been exceeded, indicating that corrective measures may need to be taken to prevent the action limit being reached.


  • Condition where the installation is complete with all services connected and functioning but with no production equipment, materials or personnel present.


  • Condition where the installation is complete with equipment installed and operating in a manner agreed upon by the customer and supplier, but with no personnel present.

 Central Air-Conditioning Unit (see air-handling unit)

Change control

  • A formal system by which qualified representatives of appropriate disciplines review proposed or actual changes that might affect a validated status. The intent is to determine the need for action that would ensure that the system Is maintained in a validated state.

Clean Area (Clean Room)1 An Area (or Room)

  • with defined environmental control of particulate and microbial contamination, constructed and used in such a way as to reduce the introduction, generation and retention of contaminants within the area.


  • Commissioning is the documented process of verifying that the equipment and systems are installed according to specifications, placing the equipment into active service and verifying its proper action. Commissioning takes place at the conclusion of project construction but prior to validation.


  • A process or device to contain product, dust or contaminants in one zone, preventing it from escaping to another zone. contamination The undesired introduction of impurities of a chemical or microbial nature, or of foreign matter, into or on to a starting material or intermediate, during production, sampling, packaging or repackaging, storage or transport.

Critical Parameter or Component

-A processing parameter (such as temperature or humidity) that affects the quality of a product, or a component that may have a direct impact on the quality of the product.


  • Contamination of a starting material, intermediate product or finished product with another starting material or material during production.

Design Condition

  • Design condition relates to the specified range or accuracy of a controlled variable used by the designer as a basis for determining the performance requirements of an engineered system.

Design Qualification (DQ)

  • DQ is the documented check of planning documents and technical specifications for conformity of the design with the process, manufacturing, GMP and regulatory requirements.

Direct Impact System

  • A system that is expected to have a direct impact on product quality. These systems are designed and commissioned in line with good engineering practice (GEP) and, in addition, are subject to qualification practices.


  • The built environment within which the clean area installation and associated controlled environments operate together with their supporting infrastructure.

Good Engineering Practice (GEP)

  • Established engineering methods and standards that are applied throughout the project life-cycle to deliver appropriate, cost-effective solutions.

 Indirect Impact System

  • This is a system that is not expected to have a direct impact on product quality, but typically will support a direct impact system. These systems are designed and commissioned according to GEP only.


  • Infiltration is the ingress of contaminated air from an external zone into a clean area.

Installation Qualification (IQ)

  • IQ is documented verification that the premises, HVAC system, supporting utilities and equipment have been built and installed in compliance with their approved design specification.

No-Impact System

  • This is a system that will not have any impact, either directly or indirectly, on product quality. These systems are designed and commissioned according to GEP only.

Non-Critical Parameter or Component

  • A processing parameter or component within a system where the operation, contact, data control, alarm or failure will have an indirect impact or no impact on the quality of the product.

Normal Operating Range

  • The range that the manufacturer selects as the acceptable values for a parameter during normal operations. This range must be within the operating range.

Operating Limits

  • The minimum and/or maximum values that will ensure that product and safety requirements are met.

Operating Range

  • Operating range is the range of validated critical parameters within which acceptable products can be manufactured.

Operational Condition

  • This condition relates to carrying out room classification tests with the normal production process with equipment in operation, and the normal staff present in the room.

Operational Qualification (OQ)

  • OQ is the documentary evidence to verify that the equipment operates in accordance with its design specifications in its normal operating range and performs as intended throughout all anticipated operating ranges.

Oral Solid Dosage (OSD)

  • Usually refers to an OSD plant that manufactures medicinal products such as tablets, capsules and powders to be taken orally.

 Performance Qualification (PQ)

  • PQ is the documented verification that the process and/or the total process related to the system performs as intended throughout all anticipated operating ranges.

Point Extraction

  • Air extraction to remove dust with the extraction point located as close as possible to the source of the dust.

 Pressure Cascade

  • A process whereby air flows from one area, which is maintained at a higher pressure, to another area at a lower pressure.


  • Qualification is the planning, carrying out and recording of tests on equipment and a system, which forms part of the validated process, to demonstrate that it will perform as intended.

Relative Humidity

  • The ratio of the actual water vapour pressure of the air to the saturated water vapour pressure of the air at the same temperature expressed as a percentage. More simply put, it is the ratio of the mass of moisture in the air, relative to the mass at 100% moisture saturation, at a given temperature.

Standard Operating Procedure (SOP)

  • An authorized written procedure, giving instructions for performing operations, not necessarily specific to a given product or material, but of a more general nature (e.g. operation of equipment, maintenance and cleaning, validation, cleaning of premises and environmental control, sampling and inspection). Certain SOPs may be used to supplement product-specific master and batch production documentation.

Turbulent Flow

  • Turbulent flow, or non-unidirectional airflow, is air distribution that is introduced into the controlled space and then mixes with room air by means of induction.

Unidirectional Airflow (UDAF)

  • Unidirectional airflow is a rectified airflow over the entire cross-sectional area of a clean zone with a steady velocity and approximately parallel streamlines (see also turbulent flow). (Modern standards no longer refer to laminar flow, but have adopted the term unidirectional airflow.)


  • The documented act of proving that any procedure, process, equipment, material, activity or system actually leads to the expected results.

Validation Master Plan (VMP)

  • VMP is a high-level document which establishes an umbrella validation plan for the entire project, and is used as guidance by the project team for resource and technical planning (also referred to as master qualification plan).


Reference :-

WHO -Quality Assurance PharmVol2



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