B
Back Pressure Residual pressure opposing the free flow of liquid or gas at the outlet side of the filter
Bioburden Measure of the contaminating organisms found in or on a given amount of material before it undergoes a sterilisation process
Brevendimonas diminuta Formerly Pseudomonas diminuta. Small bacteria used to challenge a sterilizing grade filter during validation testing

C
Cake Solids deposited on the upstream side of filter
Cartridge Filter device requiring a housing for use
Chemical compatibility Relative stability of filter material when exposed to process fluids
Clarification Removal of solids particulates from a liquid by filtration, sedimentation, centrifugation
Clean in Place (CIP) Process of rinsing or washing process components, as installed without removal, in order to remove or eliminate any contaminants
Colloid Mixture with properties between those of a solution and a fine suspension
Compatibility Term used in relation to the non reactivity of filter materials with the substance to be filtered

D
Depth Filter
Randomly distributed fibres creating a tortuous path with pores of undefined size and shape. A filter that removes particles by a combination of adsorption and size exclusion within its porous matrix rather than on its frontal surface
Deionized Water
(DI Water) Water treated by passing through both cation and anion exchange resin bed, or a mixed resin-bed to remove both positive and negative ions.
Differential Pressure (Delta P) Difference in pressure between the upstream (feed) and downstream (effluent) sides of the filter

E
Endotoxin Lipopolysaccharides from the cell walls of the bacteria. When injected they cause a febrile reaction
Extractable Chemical component that is removed from a material by solvent, temperature or time

F
Feed (influent) Unfiltered liquid stream that is introduced to filter media
Fermentation broth Fluid and all constituents in a fermentation vessel prior to separation
Filter Porous medium used for the separation of process stream components based on size exclusion and / or charge
Filter area Effective surface area of a filter that is available for filtration
Filtrate (Permeate) Fluid that has been passed through a process step
Filtration Process by which particles are removed from a fluid by passing the fluid through a permeable material
Flow rate Volumetric rate of flow of a solution expressed in l/minute

G
Gauge Pressure Pressure measured by a pressure gauge. It is expressed in units of psig, bar or kilopascal
H
Hydraulic Pressure Pressure that results from forcing liquid through an orifice, pipe or other channels

I
Integrity Test Non destructive test used to predict the functional performance of a filter

L
LAL Test Endotoxin detection and quantification using reagents produced by Limulus Amebocyte Lysate

M
Media Part of the filter through which fluid passes that retains particles during the filtration process
Micro-organisms Free-living organism too small to be seen by naked eye

P
Particle, Particulate Discernible mass having observable length, width, thickness, size and shape
Performance Qualification Documented verification that a system is capable of consistently performing or controlling the activities of the processes, according to written and pre-approved specifications
Permeability Degree to which a fluid will pass through a porous substance under specified conditions
Pore size Characteristic of a filter that specifies the size and retention capability of a filter’s pores
Porosity
(Void Volume) Percentage of a filter’s volume that is occupied by air in the filter’s pores. It is a ratio of the nonsolid volume to the total volume of material
Pressure Force applied per unit area, expressed as psi or mbar

R
Recovery
(Yeld) Mass of desired solute in the final product solution divided by the mass of the desired solute in the initial feed solution, expressed as a percentage
Retention efficiency Percentage of particles of a specific size that are removed by a filter
Reverse osmosis
(RO) Process of forcing a solvent from a region of high solute concentration, through a membrane, to a region of low solute concentration by applying a pressure in excess of the osmotic pressure. The membrane is semi-permeable, meaning it allows the passage of solvent but not solute

S
Sanitization Process of reducing microbial level (e.g.: treatment with water at 80°C or chemical treatment)
Steam in place (SIP) Sterilization of a filter in situ using steam
Sterilization Process used to render a product or an item free of living micro-organisms, including bacterial endospores
Surfactant
(Wetting agent) Soluble compound that reduces the surface tension of a liquid

T
Total Organic Carbon (TOC) Indirect measure of organic molecules present in water and measured as carbon
Turbidity Dispersed particles causing cloudiness in liquids

U
Upstream Influent side of a filter

V
Validation Documented program that provides a high degree of assurance that a specific process, method or system will consistently produce a result meeting pre-determined acceptance criteria
Volatile Easily conversion from a liquid form to gas
W
Water for Injection
(WFI) Water purified by distillation (or a purification process that is equivalent or superior to distillation) in the removal of chemicals and micro-organisms and contains no added substances
Y
Yield The quantity that would be produced at any appropriate phase of production, based upon the quantity of material to be used.

Absorption A process by which a substance is taken up chemically or physically by an absorbent material and held in pores or interstices
Aquifer A natural underground water, often of sand or gravel, that contains water
Action Level The level of lead and copper which, if exceeded, triggers treatment or other requirements that a water system must follow
Activated carbon A highly porous form of carbon used for sorption of organics and removal of some components
Adsorption Adherence of molecules, atoms and ionized species of gas or liquid to the surface of another substance
Anion Exchange Resin An ion exchange resin with immobilized positively charged exchange sites, which can bind negatively charged ionized species, anions

B

Backwash The upward flow of water through a resin or carbon bed to clean it, and in the case of a mixed bed, to separate anion and cation resins
Bactericide An agent to kill bacteria
Biocide An agent to kill micro-organisms
Biofilm A layer of micro-organisms and chemical products which are adherent to each other and / or to surfaces

C

Cartridge A disposable container that houses water purification resins, media or membranes
Cation Exchange Resin An ion exchange resin with immobilized negatively charged exchange sites, which can bind positively charged ionized species, cations
CFU/ml Colony Forming Units per 1 millilitre
Coliform A group of related bacteria whose presence in drinking water may indicate contamination by disease-causing micro-organisms
Colloid A stable dispersion of particles in water with a size less than 0.1 um. Colloids are founds in natural and potable water
Community Water System A water system that supplies drinking water to 25 people or more year-round in their residences
Condenser The part of a distillation system that removes heat from a vaporized liquid to cause the vapour to change to a liquid phase
Conductivity Reciprocal of resistivity (micro-siemens per centimetre at 25°C)
Contaminant Anything found in water (including micro-organisms, radionuclides, chemicals, minerals, etc.) which may be harmful to human health
Cryptosporidium Micro-organisms found commonly in lakes and rivers which is highly resistant to disinfection

D

Degassing The removal of O2 and CO2 from water
Deionization Removal of impurity ions from water
Disinfectant A chemical (commonly chlorine, chloramines, or ozone) or physical process (e.g.: ultraviolet light) that kills micro-organisms such as viruses, bacteria and protozoa)
Distillation Purification process that changes the phase of a substance from liquid to vapour and back to liquid, usually at the boiling temperature of the substance, in order to separate substances with different boiling points
Distribution System A network of pipes leading from a treatment plant to customer’s plumbing system

E

Endotoxin Lipopolysaccharide component from the cell wall of viable or non viable gram-negative micro-organisms (Pyrogen)
Endotoxin unit A quantification of endotoxin presence relative to a specific quantity of reference endotoxin. 1 EU/ml is appr. equal to 0.1 ng/ml
Epifluorescence Fluorescence microscopy to be used to detect bacteria enumeration after filtration and staining
Exotoxin Toxin substance secreted by a bacterium, often causing disease

F

Feed water Water that is introduced into a purification process

G

Gram-negative Bacteria that do not absorb a stain as described by Gram
Gram-positive Bacteria that absorb a stain as described by Gram
Ground Water Water that is pumped and treated from an aquifer

H

Hardness The scale-forming of some water supplies, caused by high concentrations of Ca and Mg

I

Inorganic Contaminant Mineral-based compounds such as metals, nitrates, and asbestos; naturally occurring in some water, but can also enter water through human activities
Ions Particles with positive or negative electric charge
Ion Exchange Process of purifying water by removing ionised salts form solution

L

LAL Limulus Amebocyte Lysate. An extract from the Horseshoe crab which form a gel in presence of sufficient endotoxin

M

Maximum Contaminant Level The highest level of a contaminant that EPA allows in drinking water (legally enforceable standard)
Maximum Contaminant Level Goal The level of a contaminant at which there would be no risk to human health (not a legally enforceable standard)
Micro-organisms Tiny living organisms that can be seen only under a microscope; some can cause acute health problems when consumed in drinking water

N

Non-Transient Non-Community Water System
A non-community water system that serves the same people more than six months of the year, but not year-round

O

On-line Measurement device directly coupled to a water stream
Organic Contaminants Carbon-based chemicals, such as solvents and pesticides, which enter water through cropland runoff or discharge from factories

P

Particulates Solid matter dispersed in water
Pathogen Disease-causing organism
Permeate Purified solution which has been produced by passage through a semi-permeable osmosis membrane
Potable water Water that meets regulations and is suitable for human consumption
PPB Parts per billion. Unit equal to microgram per kilogram of water
PPM Parts per million. Unit equal to milligram per kilogram of water
PPT Parts per trillion. Unit equal to nanogram per kilogram of water
Pre-treatment cartridge Disposable cartridge containing chemicals for the removal of chlorine, particles and other products prior of RO
Pyrogen Substances that can produce fever if injected or infused
Public Water System A water system which supplies drinking water to at least 25 people, at least 60 days each year

Q

Qualification Act to document that the process, equipment and materials are designed, installed, operated and perform according to the original specifications

R

Regenaration Method to reactivate the exhaust ion exchange resin with acid or alkali
Resistivity Resistivity is reciprocal of conductivity. The value is reported as megohm-centimetre at 25°C
Reverse Osmosis (RO) Process in which water is forced under pressure through a semi-permeable membrane leaving behind dissolved organic, dissolved ionic and impurities

S

Sanitization Chemical or physical process to reduce contamination from micro-organisms
Sensitive Sub-population People who may be more vulnerable to drinking water contamination, such as infant, children, some elderly, and people with severely compromised immune systems
Septic System Used to treat sanitary waste; can be a significant threat to water quality due to leaks or runoff
Softening Water treatment process where cations are exchanged for Na using cation exchange resin
Source Water Water in its natural state, prior to any treatment for drinking (i.e.: lakes, streams, ground water)
Sterilization Destruction (e.g.: by heating) or removal (e.g.: by filtration) of all living micro-organisms
Surface Water Water that is pumped and treated from sources open to the atmosphere, such as rivers, lakes, and reservoirs

T

Total Dissolved Solids (TDS) Total organic and inorganic salts dissolved in water, obtained by drying residue at 180°C
Total Organic Carbon (TOC) Total carbon present in organic compounds
Transient Non-Community Water System
A non-community water system that serves the public but not the same individuals for more than six months

U

Ultra-filtration Water is filtered through a special membrane with a very fine structure

V
Validation Confirmation that specific intended use has been fulfilled

Violation Failure to meet any state or federal drinking water regulation
Vulnerability Assessment An evaluation of drinking water source quality and its vulnerability to contamination by pathogens and toxic chemicals

W

Watershed The land area from which water drains into a stream, river, or reservoir
Well A bored, drilled or driven shaft whose depth is greater than the largest surface dimension, a dug hole whose depth is greater than the largest surface dimension, an improved sinkhole, or a subsurface fluid distribution system.

http://labmanual.net/docs/FTP/files/LaboratoryvalidationDefinitionsAndTerminology.pdf

Air volume – Rate of airflow, normally expressed in cubic feet per minute (CFM).

ASHRAE – American Society of Heating, Refrigerating, and Air Conditioning Engineers.

Auxiliary air – Supply or makeup air delivered external to the chamber of a fume hood to reduce air consumption.

Baffle – Panels located across back of hood interior, which control pattern of air moving through the hood.

Blower – Air moving device (or fan) consisting of motor, impeller, and scroll.

Bypass – Compensating opening that helps maintain constant volume exhaust from fume hood, regardless of sash position.

Canopy hood – Ceiling or wall suspended ventilating device for non critical use with heat, water vapour, odors, etc.

CMF – Cubic Feet per Minute, a unit of measurement of air volume.

Combination Sash – Horizontal panels in a vertical rising frame; see sash.

Constant Volume – Type of fume hood exhaust system that exhausts the same volume of air, regardless of sash position.

Containment – Extent to which fumes are confined within the hood compartment.

Damper – Device installed in duct to control air volume.

Demonstration hood – Fume hood with glass panels on two or three sides to improve visibility for demonstrating experiments in a classroom setting.

Exhaust volume / parameters – Quantity of air exhausted by the fume hood; quantity of air required to maintain desired face velocity, expressed in cubic feet per minute (CFM).

Face velocity – Speed of air moving into the fume hood through the face opening (through the sash), measured in feet per minute (FPM).

FPM – Feet Per Minute; measurement of air velocity.

Liner – Fume hood interior sides, back, and top, including baffle.

Lintel – Portion of fume hood front located above access opening.

Louvers – Slit-like openings in the lintel that allow bypass air to enter the hood when the sash is closed.

NFPA – National Fire Protection Association.

Negative Pressure – Pressure lower than one atmosphere.

Positive Pressure – Pressure higher than one atmosphere.

Restricted Bypass Fume Hood – Fume hood operating type, designed with limited bypass area; commonly used in conjunction with Variable Air Volume (VAV) exhaust system and restricted sash opening designs.

Sash – Sliding glass panel set in the fume hood face that provides access to the hood interior.
Service Fitting / Plumbing – Water faucets and gas valves mounted on or fastened to the fume hood.

Static Pressure – Air pressure, or resistance, in fume hood or duct, expressed in inches of water.

U.L. 1805 – Underwriters Laboratories certification that verifies conformance to electrical, mechanical., and airflow standards.

Variable Air Volume (VAV) – Type of fume hood exhaust system that typically maintains constant fume hood face velocity by adjusting blower motor speed or a balance damper in response to changes in sash position.

Velocity – Speed of air, measured in Feet Per Minute (FPM).

Velocity Pressure – Force per square inch applied by moving air.

Volume – Quantity of air, usually measured in Cubic Feet per Minute (CFM).

Work surface – Top material; area in fume hood where apparatus rests and where work takes place.