Glossary of terms

This glossary includes some of the terms and abbreviations used regularly in the pharmaceutical water and sterilisation arenas. If there are other terms you feel would help please let us know and we will include them in this list.

Active drain:
A drain, which is situated at the lowest part of the sterilizer chamber to control the discharge of air/non-condensable gases or air and condensate from the sterilizer chamber.
Air detector:
A device used to determine that sufficient air or other non-condensable gases have been removed from the chamber.
Air removal:
Removal of air from the sterilizer chamber and sterilizer load sufficient to facilitate steam penetration.
Automatic controller:
Device that, in response to pre-determined cycle variables, operates the sterilizer sequentially through the required stages of the cycle(s).
Automatic control test:
A test designed to show that the operating cycle functions correctly as evidenced by the values of the cycle variables indicated and recorded by the instruments fitted to the sterilizer.
Bioburden:
Population of viable micro-organisms on a product and/or package.
Biological indicator:
An inoculated carrier contained within its primary pack ready for use.
Calibration:
The set of operations that establish, under specified conditions, the relationship between values of a quantity indicated by a measuring instrument or measuring system, or values represented by a material measure or a reference material, and the corresponding values realised by standards.
Chamber depth:
Depth of the sterilizer chamber which is available for the sterilizer load.

Chamber height:
Height of the sterilizer chamber which is available for the sterilizer load.

Chamber width:
Width of the sterilizer chamber which is available for the sterilizer load

Chamber temperature:
Lowest temperature prevailing in the sterilizer chamber.


Chemical Indicator:
A device designed to show, usually by a change of colour; whether specified values of one or more cycle variables nave been attained.

Disinfection:
A process used to reduce the number of viable micro-organisms in a load but which may not necessarily inactivate some viruses and bacterial spores.

Dedicated steam supply:
Supply of steam produced for a sterilizer, or group of sterilizers, by a dedicated generator.

Door:
Lid or similar device provided as a means of closing and sealing the sterilizer chamber.

Double ended sterilizer:
Sterilizer in which there is a door at each end of the sterilizer chamber.

Dryness value:
A dimensionless quantity approximating to the dryness fraction, derived to determine whether steam is of the correct dryness for sterilization purposes. A dryness value of 1.0 represents dry saturated steam.

Dry saturated steam:
Steam with a temperature and pressure corresponding to the vaporisation curve of water.

NOTE: This is an ideal condition, which can deviate towards either superheated steam or to wet steam. This deviation is quantified by the determination of the Dryness Value.

D-value:
Decimal reduction value (for biological indicators". The time in minutes required to secure inactivation of 90% of the test organisms under stated exposure conditions.

Equilibration time:
Period which elapses between the attainment of the sterilization temperature in the sterilizer chamber and the attainment of the sterilization temperature at all points within the load.

Fail safe:
Attribute of sterilizer design, component or its associated services that minimises a possible safety hazard.

Fault:
Recognition by the automatic controller that the pre-set cycle variables for the sterilization cycle have not been attained.

Holding time:
Period for which the temperature of all points within the sterilizer is held within the sterilization temperature band.

NOTE: The holding time follows immediately after the equilibration time. The extent of the holding time is related to the sterilization temperature

Inoculated carrier:
A carrier on which a defined number of test organisms has been deposited.

Installation test:
Series of checks and tests performed after installation of the sterilizer in the place of use.

Loading door:
Door in a double ended sterilizer through which the sterilizer load is put into the sterilizer chamber prior to sterilization.

Medical device:
The definition given in EN 46001 applies.

Moist heat:
Heat that is derived from water, either as a liquid or as steam under pressure.

Parametric release:
Declaring product as 'sterile' based on physical process data rather than on the basis of sample testing or biological indicator results.

Performance qualification:
Obtaining and documenting evidence that the equipment as commissioned will produce acceptable product when operated in accordance with the process specification.

Plateau period:
Equilibration time plus the holding time.

Primary standard:
Standard that is designated or widely acknowledged as having the highest metrological qualities and whose values are accepted without reference to other standards.

Product compatibility:
Ability of the sterilization cycle to achieve the intended results without detrimental effect on the product.

Non-condensable gas:
Air and other gas which will not condense under the conditions of steam sterilization.

Pressure vessel:
A vessel describing the sterilizer chamber, jacket (if fitted), door(s) and components that are in permanent connection with the sterilizer chamber.

Recommissioning:
Procedure to confirm that the sterilizer functions in accordance with its specification and that data established during commissioning remain valid.

Reference measurement point:
Reference point for which documented evidence is available to demonstrate that it has a known relationship to the temperature of the coolest part of the sterilizer chamber.

Reference load:
Specified load made up to represent the most difficult combination of products to be sterilized.

Reference standard:
Standard, generally having the highest metrological quality available at a given location or in a given organisation, from which measurements made there are derived.

Safety hazard:
Potentially detrimental effect on persons or the surroundings arising directly from either the sterilizer or its load.

Saturated steam:
Water vapour at a temperature corresponding to the boiling point of the source liquid.

Small steam sterilizers:
Steam sterilizer which is unable to accommodate a sterilization module.

Sterile:
Condition of a medical device that is free from viable micro-organisms.

Sterilization:
Process undertaken to render a sterilizer load sterile.

Sterilization cycle:
Automatic sequence of operating stages performed in a sterilizer for the purpose of sterilization.

Sterilization: temperature:
Minimum temperature of the sterilization temperature band.

Sterilization temperature band:
Range of temperatures, expressed as the sterilization temperature and the maximum allowable temperature which may prevail throughout the load during the holding time.

NOTE: These temperatures are usually stated in whole degrees Celsius.

Sterilizer:
Apparatus designed to achieve sterilization.

Sterilizer chamber:
That part of the sterilizer which receives the sterilizer load.
Sterilizer load:
Goods that are to be sterilized simultaneously in the same sterilizer chamber.

Superheated steam:
Steam whose temperature, at any given pressure, is higher than that indicated by the vaporisation curve of water.

Test organism:
Micro-organisms used for the manufacture of inoculated carriers.

Type test:
Series of tests to establish the working data for a sterilizer type.

Unloading door:
Door in a double ended sterilizer through which the sterilized load is removed from the sterilizer chamber after a sterilization cycle.

Usable space:
Space inside the sterilizer chamber which Is not restricted by fixed parts and which is consequently available to accept the sterilizer
load.

NOTE: The usable space is expressed in terms of chamber height, chamber width and chamber depth.


Validation:
Documented procedure for obtaining, recording and interpreting data required to show that a process will consistently comply with predetermined specifications.

Works test:
Series of tests performed at the manufacturer's works to demonstrate compliance of each sterilizer with its specification.

 

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