The following list of common contamination-control and cleanroom terms & definitions may be helpful when navigating our website.  

Absolute filter
See HEPA filter.

Activated carbon filter
See Gas-phase adsorber cell. See also Adsorption.

Adhesion of the molecules of liquids, gases, and dissolved substances to surfaces of solids; as opposed to absorption, taking of molecules of one substance directly into another substance. It is contrasted with adsorption , in which the molecules adhere only to the surface of the second substance.

Air filter
An air cleaning device that removes particulate contamination from an airstream by straining, impingement, interception, electrostatic attraction or absorption.

Air lock
An airtight room adjoining cleanrooms or containment laboratories that acts as a buffer zone between two independent areas of unequal pressure. A pressure differential of ≥ 15 Pa is typically maintained between the inner room and the air lock; and between the air lock and the external area. Also termed Ante-room.

Air velocity
Measured in metres/ second (m/s) or feet/ minute (ft/min). 1 m/s = 196.8 ft/min

The Australian Institute of Refrigeration, Air Conditioning and Heating is a specialist membership association for air conditioning, refrigeration, heating and ventilation professionals. Formed in 1920, AIRAH is recognised by government and industry bodies for its expertise across a wide range of issues in the area of engineering services for the built environment.

Measured in cubic metres/second (m3/s), litres/second (L/s) or cubic feet/minute (ft3/min or cfm). 1 ft3/min = 0.0004719 m3/s

Airflow uniformity
In unidirectional/ laminar airflow systems, the required airflow pattern downstream of the HEPA filter installation where all velocity readings are within 20% of the average air velocity.

ARBS (Air Conditioning, Refrigeration & Building Services) is the major trade event for the Heating, Ventilation, Air Conditioning, Refrigeration and Building Services industry in the southern hemisphere. Held every two years.

AS 1386
Australian Standard 1386 – 1989: Cleanrooms and Clean Workstations has 7 parts. These are:

  • Part 1: Principles of clean space control (AS 1386.1)
  • Part 2: Laminar flow cleanrooms (this Standard, AS 1386.2)
  • Part 3: Non-laminar flow cleanrooms—Class 350 and cleaner (AS 1386.3)
  • Part 4: Non-laminar flow cleanrooms—Class 3500 (AS 1386.4)
  • Part 5: Clean workstations (AS 1386.5)
  • Part 6: Operation and inspection of cleanrooms (AS 1386.6)
  • Part 7: Installation and use of clean workstations (AS 1386.7)

This standard will be superseded by the adoption of ISO 14644.

AS 1807
Australian Standard 1807.0 -2000: Cleanrooms, Workstations, Safety Cabinets and Pharmaceutical Isolators – Methods of Test. Describes apparatus and test methods for controlled environment applications, including HEPA filter installations; cleanrooms; laminar flow and safety cabinets and pharmaceutical isolators.

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers is an international organization operated for the exclusive purpose of advancing the arts and sciences of HVAC & R (heating, ventilation, air-conditioning, and refrigeration), the allied arts and sciences, and the related human factors for the benefit of the public. ASHRAE has over 175 standards, some written jointly with ANSI and IES. ASHRAE standards describe uniform methods of testing, specify design requirements, and recommend standard practices. They also publish numerous handbooks on fundamentals, applications, refrigeration, and several other comprehensive subjects.

Australian GMP Code for medicinal products
The Australian Code of Good Manufacturing Practice for Medicinal Products (16 August 2002), replaces the Australian Code of Good Manufacturing Practice for Therapeutic Goods – Medicinal Products (August 1990), the Australian Code of Good Manufacturing Practice for Therapeutic Goods – Medicinal Gases (July 1992) and the Investigational Medicinal Products Code of GMP (Annex 13, EC GMP Guide, 1997).

Australian cleanroom standards
See AS 1386

Automatic roll filter
See Auto-roll filter

Auto-roll filter
An air filter with a static-pressure-operated mechanism that advances a roll of filter medium to maintain a panel of clean medium in the filter opening. Also known as Automatic roll filter.

Baghouse collector
A baghouse is a dust collection system used to trap particulates by filtering air streams through large fabric bags typically made of glass fibres or fabric.

Class 350 cleanroom
A cleanroom in which there are no more than 350 particles per litre at ≥ 0.5 um, and no more than 2 particles ≥ 5.0 um. Equivalent to ISO Class 7; or US Standard 209E Class 10,000.

Class 3500 cleanroom
A cleanroom in which there are no more than 3500 particles per litre at ≥ 0.5 um, and no more than 20 particles ≥ 5.0 um. Equivalent to ISO Class 8; or US Standard 209E Class 100,000.

Clean-air device, laminar flow
A laminar flow enclosure, clean bench, clean work station, wall or suspended ceiling module, or other device (except a cleanroom) which incorporates a HEPA filter(s) and a fan(s) to supply laminar flow clean air to a controlled work space.

A room or suite of rooms in which controlled limits may be set for:-

  • air flow patterns
  • air cleanliness
  • viable and non-viable airborne particles
  • temperature and relative humidity
  • air pressure
  • operating procedures

Cleanroom classifications – cross-reference between standards

Standard Classification
 ISO 14644-1 3 4 5 6 7
 AS 1386 0.035 0.35 3.5 35 350 3,500
 BS 5295 C D E/F G/H J K
 Federal Standard 209E 1 10 100 1,000 10,000 100,000

More information

Cleanroom facility – As Built
A cleanroom facility that is complete and ready for operation, with all services connected and functional, but without production equipment or personnel.

Cleanroom facility – At Rest
A cleanroom facility that is complete with production equipment installed, but without personnel.

Cleanroom facility – In Operation
A cleanroom facility in normal operation, with all services functioning and with production equipment and personnel present.

Cleanroom garments
Special clothing designed to protect cleanroom environments from contaminants released by workers. Special apparel includes non-shedding gowns or coveralls, head covers, face masks, gloves, footwear or shoe covers.

Contained Space
A building, building zone, room, micro-environment, glovebox, or other enclosure in which air supply and exhaust are controlled.

The use of HEPA filters and controlled airflow inside a cabinet; or other enclosure; or room to capture and contain hazardous aerosols. Examples are containment laboratories in accordance with AS 2243.3; or cytotoxic drug manufacturing facilties in accordance with AS 2639.

Cyclone dust collector
Cyclone collectors that remove particulates in air streams by centrifugal action.

Deep bed filter
An air filter with a filter catridge that has an effective filter medium area at least 3 times the filter face area.

Dispensary booths
See Downflow booths.

Dioctyl Phthalate – a fluid pthalate esther used as a pnuematically-generated aerosol for integrity testing of HEPA filters. An aerosol photometer detects penetration of aersol through the filter. Alternative fluids with similar particle-size distribution, such as BP-grade parrafins and Poly-Alfa-Olefins (PAOs) are widely used.

Downflow booths
Laminar flow enclosures with exhaust filtration that provide a controlled environment by means of controlled airflows and multi-stage high-efficiency air filter systems.

Dust collector
A system for collecting process-generated dusts from the source point on a continuous basis. Collectors may be a single unit; or a combination of devices used to separate particulates from process air. They act as a device to control air pollution to maintain or improve air quality.

Electrostatic discharge (ESD)
The sudden discharge (transfer) of electricity from one surface to another. ESD is typically caused by friction between plastics, fabrics or coated surfaces.

EUROVENT-CECOMAF is the European Committee of Air Handling and Refrigeration Equipment Manufacturers. Its main activities are:

  • Keeping members informed of relevant legislation
  • Developing a reliable global statistic reporting system
  • Developing product certification programmes
  • Participating in international standardisation
  • Disseminating information on matters such as refrigerants, energy & indoor air
  • Publishing guides and technical application manuals
  • Developing co-operative research projects

Extended surface filter
An air filter with an effective filter medium area that is at least 1.5 times the filter face area. Filters are typically 50 mm or 100 mm deep, with the filter medium arranged in a vee-form.

Filter medium
The part of an air filter that provides filtration. Materials include non-woven synthetic fibres, acrylics, activated carbon, aluminium mesh, electrostatic fabric, paper, polyurethane foam, polyester and poly/cotton composites. Also known as filter media.

Fume and smoke collectors
This type of collector removes sub-micron particulates from the air. They reduce or eliminate the concentration of particulates and gases from industrial processes such as welding; processing rubber and plastics; coolants for high-speed metal machining, tempering and quenching.

Gas-phase adsorber cell
A gas-phase adsorbtion filter for single-pass or recirculating air-cleaning systems where removal of gaseous contaminants is required. Also known as Molecular filters.

An enclosure, fitted with sealed gloves, that allows external manual manipulations in controlled or hazardous environments. Applications include nuclear, biomedical, semiconductor, chemical industries; and research laboratories – where isolation of the controlled zone is required .

Grease arrestance filter
An air filter to trap airborne oils and fats in exhausts from cooking applications. The filter medium is typically metal; and the hot contaminants condense on the cooler metal surfaces. Designs include honeycomb panels, mesh screens and baffles. Also known as Range hood filters.

HEPA filter
A High Efficiency Particulate Air filter as defined in AS 4260 and EN 1822.

HEPA filter high capacity
Filters designed to handle increased airflow – 610 x 610 x 292 mm filters handle 944 L/s at 350 Pa initial resistance.

HEPA high temperature
Filters designed for ovens in cleanrooms and laboratories, available in ratings up to 400 °C. Frame construction of stainless steel or aluminium, fitted with silicone or glass gasket, depending on temperature.

HEPA filter module
A HEPA filter fitted into a lightweight, disposable housing that is designed for terminal installation in cleanroom ceilings. Non-fan-assisted modules have a round top spigot for duct connection; and the fan-assisted type has a top intake grille that can be fitted with a prefilter.

ISO cleanroom classifications
Adoption of ISO standards makes national standards such as AS 1386 redundant. Air cleanliness classifications are in ISO-14644-1 Classification by Airborne Particles. This is complemented by ISO-14698, dealing with bio-contamination control and monitoring.

Laminar air flow
A HEPA-filtered air stream moving within a confined space, along parallel flow lines, with uniform velocity. ‘Laminar air flow’ is a misnomer; more correctly termed ‘unidirectional flow’.

The design and manufacture of integrated circuits and of equipment that uses integrated circuits.

See Micron.

A unit of measurement equal to one-millionth of a metre; or one-thousandth of a millimetre; or approximately 0.00003937 inch. Expressed as µm.

Minipleat HEPA filter
HEPA & ULPA filters of light weight, low-depth construction with very close pleating of the medium; separation of media pleats achieved by continuous, narrow beads of a hot-melt compound. Typically, a 70 mm deep minipleat filter has similar airflow/ pressure drop characteristics to a 149 mm conventional filter of the same face dimensions.

Mist collector
These collectors remove particulates in the form of fine liquid droplets from the air. They are often used for the collection of fluids used in metal working as coolants or lubricants; and are used to improve or maintain the quality of air in a work environment.

Multi-pocket filter
An extended surface air filter with the filter medium arranged in pockets to maximize the effective filter area. Filters are typically 300–900 mm deep, with up to 10 pockets.

NATA is Australia’s national provider of laboratory and inspection accreditation services and GLP compliance monitoring.

Panel filter
A relatively shallow air filter that is disposable; or may have replaceable medium. Filters are typically 25 -100 mm deep, with a single or double-layer of filter medium.

See DOP.

Particle counter – airborne
An electronic instrument for continuous counting of airborne particles larger than a selected diameter. The light-scattering principle is used to display and record the number and size of discrete particles.

Pass-through hatches
Pass-through hatches protect critical environments while allowing transfer or materials to or from adjoining rooms. Typical installations are in the walls of cleanrooms and biological containment laboratories. In these applications, materials must be transferred with minimal loss of room pressure; and without the need for personnel movement between rooms.

PC3 containment facility
Physical Containment Level 3 facilities are negative-pressure containment laboratories specified in AS/NZS 2243.3:2002. PC3 facilities are suitable for work with Risk Group 3 pathogens and certain Genetically Modified Organisms.

An air filter fitted to protect downstream filters from large dust particles.

Pressure drop & room pressure
Measured in Pascals (Pa); mm of H20; or inches water gauge. 1″ w.g. = 249.088 Pa. In-situ instrumentation to indicate pressure is typically a Dwyer Instruments Magnehelic gauge(s).

PTFE membrane ULPA filter
Designed to meet stringent cleanroom filtration requirements for semiconductor industry. Ultra-high efficiency with low pressure drop. Classification U16 according to EN 1822, 99.99995 % minimum efficiency at MPPS.

Pulse collector cartridges
These cartridges are a heavy-duty, high efficiency cylindrical filter developed specifically for self-cleaning pulse-type air filtration systems. They are designed to operate under the severe environmental conditions of gas turbine, engine and centrifugal compressor applications.

Recovery of process materials
Dust collectors are used in a wide range of industrial processes to recover valuable granular solids or powders from process exhaust air streams prior to venting to atmosphere.

Room pressure
See Pressure drop & room pressure. Pressure differentials between cleanrooms and adjoining zones are typically specified as ≥ 15 Pa.

Separative devices
See Clean-air device, laminar flow . ‘Separative devices’ is the terminology adopted for ultra-clean enclosures in ISO 14644-7, Cleanrooms and associate controlled environments – Part 7: Separative devices (clean air hoods, gloveboxes, isolators and minienvironments).

Spray booth filter media
Specialised filter media for supply and exhaust air in paint spay booths.

  • Supply media – also known as ‘downdraught media’ – has a dense layer on the clean air-leaving side and a special adhesive which reduces dust migration caused by vibration. Performance rating is F5.
  • Exhaust media is designed to arrest paint overspray and has a performance rating of G3.

Sterile air
Air supply that is filtered to exclude microbiological life, e.g. bacteria, yeasts, moulds, fungi and viruses.

The Therapeutic Goods Administration (TGA) is a unit of the Australian Government Department of Health and Ageing. The TGA carries out a range of assessment and monitoring activities to ensure therapeutic goods available in Australia are of an acceptable standard with the aim of ensuring that the Australian community has access, within a reasonable time, to therapeutic advances.

TGA Code
See Australian GMP Code for medicinal products.

Turbulent flow cleanroom
A non-unidirectional flow cleanroom in which air enters the room with non-uniform velocity; or with turbulent flow. Examples are ISO 14644-1 cleanrooms of Class 6, 7 and 8.

ULPA filter
An Ultra Low Penetration Air filter. A HEPA-type filter with higher efficency filter medium. Originally devloped for cleanroom applications in semiconductor manufacture.

ULPA filter module
As for HEPA filter module, but with higher efficiency rating.

Unidirectional flow cleanroom
Formerly termed ‘Laminar flow cleanroom’.

Procedures to create documented evidence that a facility meets design, construction and/or performance specifications.

Wet scrubbers
Wet scrubbers – also termed Venturi scrubbers – are similar to a cyclone with the addition of an orifice that sprays water into the vortex of the cyclone, thereby collecting dust in slurry form.