Cleanroom Acronyms & Glossary


  • ACPH
  • BSC
  • CAI
  • CACI
  • CVE
  • LAFW
  • ISO#  
  • C PEC
  • C SEC
  • HD
  • HEPA
  • SOP
  • API
  • AHCA
  • BUD
  • FDA
  • BI
  • CSP
  • DCA
  • HVAC
  • IPA
  • ISO
  • NIST
  • USP
  • LOD
  • SAR
  • CDC
  • PPE
  • AHU
  • Air Changes Per Hour
  • Biological Safety Cabinet
  • Compounding Aseptic Isolator
  • Compounding Aseptic Containment Isolator
  • Containment Ventilated Enclosure
  • Laminar Air Flow Workbench
  • Particle Count Rating
  • Containment Primary Engineering Control
  • Containment Secondary Engineering Control
  • Hazardous Drug
  • High-Efficiency Particulate Air
  • National Institute for Occupational Safety and Health
  • Standard Operating Procedure
  • Active Pharmaceutical Ingredient
  • Agency of Health Care Administration
  • Beyond Use Date
  • Food and Drug Administration
  • Barrier Isolator
  • Compound Sterile Preparation
  • Direct Compounding Area
  • Heating Ventilation and Air Conditioning
  • Isopropyl Alcohol
  • International Organization of Standardization
  • National Institute for Standards and Technology
  • United States Pharmacopeia
  • Line of Demarcation
  • Small Acrylic Room
  • Centers for Disease Control and Prevention
  • Personnel Protective Equipment
  • Air Handling Unit


Buffer Area

An area where the primary engineering control (PEC) is physically located. Activities that occur in this area include the preparation and staging of components and supplies used when compounding CSP’s.


(also see definition of buffer area) a room in which the concentration of airborne particles is controlled to meet a specified airborne particulate cleanliness class. Microorganisms in the environment are monitored so that a microbial level for air, surface, and personnel gear are not exceeded for a specified cleanliness class.


An ISO Class 8 or better area where personnel hand hygiene and garbing procedures, staging of components, order entry, CSP labeling, and other high particulate generating activities are performed. It is also a transition area that provides assurance that pressure relationships are constantly maintained so that air flows from clean to dirty areas and reduced the need for the HVAC control system to respond to large disturbances.

Hazardous Drug

Drugs are classified as hazardous if studies in animals or humans indicate that exposures to them have a potential for causing cancer, development or reproductive toxicity, or harm to organs.

Air Lock

A space of separation between two different air pressures; may be a pass-through chamber or room; a door must be present to prevent loss of pressure in the high pressured room.

Air Pressure

Can be either positive or negative; positive air pressure environments may only be used for nonhazardous sterile preparations. Negative pressure environments can be used to prepare both hazardous and non-hazardous sterile preparations.

Acrylic Return

Takes air from room and recycles it back through HEPA filters to reduce the demand/ size of air handling unit (AHU) needed by almost half.

Critical Area

An ISO Class 5 environment

Negative Room Pressure

A room that is at a lower pressure than the adjacent spaces, and therefore , the net airflow is into the room

Positive Pressure Room

A room that is at a higher pressure than the adjacent spaces, and therefore , the net airflow is out of the room

Segregated Compounding Area

A designated space, either a demarcated area or room, that is restricted to preparing low-risk level CSP’s with 12-hour or less BUD.

Externally Vented

Exhausted to the outside


An enclosure with interlocking doors that is positioned between two spaces for the purpose of reducing particulate transfer while moving materials from one space to another. A pass through serving negative-pressure rooms needs to be equipped with sealed doors.