LABORATORY MANAGEMENT - WLT 06201 NOTES 1.0 Manage samples, waste generated from laboratory activities, Chemicals and equipment according to standards: 1.1 Manage soil, water and wastewater samples Prepare a sampling plan to ensure collection of the representative samples. Since sample collection can be considered as the first step in the analytical work it is desirable to collect the samples by laboratory personnel. Objective of the sampling activities in analytical procedures is to obtain a representative quantity of material small enough to be handled and transported to a laboratory and yet large enough for analytical purposes while still accurately representing the material being sampled. Sampling and sample pretreatment should be carefully done under the guidance of experienced personnel who is in charge of the sampling procedure. Considering that the sampling procedure is the first step of the analysis it should be pointed out that any mistakes which were made in taking the sample will cause an error in the final data regardless of the qualification of the analyst in the laboratory and the superior quality of instruments used. When transferring samples from the collection equipment to the storage container, care should be taken to ensure the continuance of anaerobic conditions if appropriate to the planned analysis. The maintenance of anaerobic conditions will to a large extent depend on the equipment being used. Similarly, the use of a metal spatula should be avoided if trace metals are of interest. The type and composition of sample transfer tools should be noted in the field notebook. Types of water samples: 1. Grab samples are single samples collected at a specific spot at a site over a short period of time (typically seconds or minutes). Thus, they represent a "snapshot" in both space and time of a sampling area. 2. Composite samples provide a more representative sampling of heterogeneous matrices in which the concentration of the analytes of interest may vary over short periods of time and/or space. Composite samples can be obtained by combining portions of multiple grab samples or by using specially 1
Transcript
LABORATORY MANAGEMENT - WLT 06201 NOTES
1.0Manage samples, waste generated from laboratory activities, Chemicals and equipment according to standards:
1.1 Manage soil, water and wastewater samples Prepare a sampling plan to ensure collection of the
representative s a m p l e s . Since sample collection can be considered as the first step in the analytical work it is desirable to collect the samples by laboratory personnel.
Objective of the sampling activities in analytical procedures is to obtain a representative quantity of material small enough to be handled and transported to a laboratory and yet large enough for analytical purposes while still accurately representing the material being sampled.
Sampling and sample pretreatment should be carefully done under the guidance of experienced personnel who is in charge of the sampling procedure.
Considering that the sampling procedure is the first step of the analysis it should be pointed out that any mistakes which were made in taking the sample will cause an error in the final data regardless of the qualification of the analyst in the laboratory and the superior quality of instruments used.
When transferring samples from the collection equipment to the storage container, care should be taken to ensure the continuance of anaerobic conditions if appropriate to the planned analysis. The maintenance of anaerobic conditions will to a large extent depend on the equipment being used. Similarly, the use of a metal spatula should be avoided if trace metals are of interest. The type and composition of sample transfer tools should be noted in the field notebook.
Types of water samples:1. Grab samples are single samples collected at a specific spot at
a site over a short period of time (typically seconds or minutes). Thus, they represent a "snapshot" in both space and time of a sampling area.
2. Composite samples provide a more representative sampling of heterogeneous matrices in which the concentration of the analytes of interest may vary over short periods of time and/or space.
Composite samples can be obtained by combining portions of multiple grab samples or by using specially
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designed automatic sampling devices.
Sequential (time) composite samples are collected by using continuous, constant sample pumping or by mixing equal water volumes collected at regular time intervals.
Flow-proportional composites are collected by continuous pumping at a rate proportional to the flow, by mixing equal volumes of water collected at time intervals that are inversely proportional to the volume of flow, or by mixing volumes of water proportional to the flow collected during or at regular time intervals.
Selection of sample containers:The type of sample container used is of extreme importance. Test sample containers and make sure that they are free of analytes of interest, especially when sampling and analyzing for very low analyte levels. Containers typically are made of plastic or glass, but one material may be preferred over the other.
For example, silica, sodium, and boron may be leached from soft glass but not plastic, and trace levels of some pesticides and metals may adsorb onto the walls of glass containers. Thus, hard glass containers are preferred.
For samples containing organic compounds, do not use plastic containers except those made of fluorinated polymers such as polytetrafluoroethylene (PTFE).
Some sample analytes may dissolve (be absorbed) into the walls of plastic containers; similarly, contaminants from plastic containers may leach into samples.
Avoid plastics wherever possible because of potential contamination from phthalate esters.
Therefore, use glass containers for all organics analyses such as volatile organics, semivolatile organics, pesticides, PCBs, and oil and grease.
Some analytes (e.g., bromine-containing compounds and some pesticides, polynuclear aromatic compounds, etc.) are light-sensitive; collect them in amber-colored glass containers to minimize photo- degradation.
Sample pre-treatment To minimize the potential for volatilization or biodegradation
between sampling and analysis, keep samples as cool as possible
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without freezing. No single method of preservation is entirely satisfactory; choose the preservative with due regard to the determinations to be made.
Use chemical preservatives only when they do not interfere with the analysis being made.
Methods of preservation are relatively limited and are intended generally to retard biological action, retard hydrolysis of chemical compounds and complexes, and reduce volatility of constituents.
Preservation methods are not limited to: pH control, chemical addition, the use of amber and opaque bottles, refrigeration, filtration, centrifugation and freezing.
o If freezing the sample is chosen as the preferred method of preservation as defined by the sampling programme and specified analytical method it is therefore essential for the sample to be completely thawed before use, as the freezing process may have the effect of concentrating some components in the pore water of the inner part of the sample.
o All preservation steps should be recorded in a site report and the temperature measured and recorded on site. If appropriate, other physical and chemical parameters should be determined on site or as soon as possible after sample collection.
o In practice every analytical exercise sets its own particular pre -treatment demands in the field a s s t i pu l a te d i n t he ana l y t i ca l p ro toco l s . The analysis plan prepared for the field sampling should include this section taking into account the particular requirements for the sample pre-treatment and storage containers before analyst. For example: Samples containing suspended sediment should be filtered as soon
as possible after collection. The filtrate can then be used for measuring the dissolved constituents. Sediment samples should generally be kept in glass containers and stored and transported cool. If it is necessary to keep them longer than one month, then this should be done in a deep freezer, giving due regard to the physicochemical changes that can occur to colloids on freezing.
Polyethylene containers or polypropylene bag are recommended for analysis of carbon, heavy metals, nitrogen and phosphorus a
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sa mp le can be stored in or jar frozen to -20oC for the period of max. 6 months.
Samples for analysis of chlorinated hydrocarbons, pesticides and organic pollutants can be extracted immediately and stored in glass jar or frozen to - 20oC and extracted as soon as possible.
o In all cases sample containers should be delivered to the laboratory tightly sealed and protected from light and excessive heat, because the sample may change rapidly due to gas exchange, chemical reactions and the metabolism of organisms.
1.2 Manage waste generated from laboratory activitiesTypes of Laboratory WastesA wide range of wastes arise in chemical laboratories. Examples include:
Liquids, such as aqueous solutions, oils and solvents Sludges, which can be both aqueous and non-aqueous Solid materials, such as chemicals, glass, packaging, papers,
waste samples and equipment.
Waste management in chemical laboratories must follow guiding principles for planning laboratory programmes and waste control measures:
i. Reduce waste at source where possible. In a laboratory context this could mean planning work carefully so as to minimize raw material consumption.
ii. Put objects back into use (reuse). Cleaning and re-labeling reagent bottles for re-use, or returning them to supplier is the best option.
iii. Recover value from waste by recycling. iv. Incinerate non-recyclable combustibles, [using approved methods to minimize atmospheric pollution], In order to reduce waste volume and toxicity.
v. As a last resort, render the waste less environmentally harmful by an appropriate treatment and dispose of it to landfill. The amount of waste discharged to landfill should have the lowest practicable volume and the lowest achievable environmental toxicity.
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Liquid wastes / Aqueous Waste (call for special attention)CyanideSmall quantities of cyanide waste should be converted to carbonate, by mixing it in a large beaker in a fume cupboard with a slight excess of Sodium hypochlorite solution. The reaction is normally complete in a couple of days. When the cyanide has been destroyed, the resultant waste may then be sent to drain after heavy dilution with water.
Chromium VIWaste containing Chromium (VI) should be reduced to Chromium (III) with an appropriate agent, Iron (II) solution or Sodium Sulfite for example, which will be more acceptable for effluent treatment.
SulfideThe addition of zinc sulfate to a solution of sulfide will precipitate zinc sulfide, which may be collected in a suitable container, and stored for ultimate disposal, with other redundant chemicals. The solution remaining can be sent to drain.
Organic LiquidsSolventsWaste organic solvents should be stored in separate labeled containers according to type (chlorinated and non-chlorinated), both to reduce risk of chemical reaction.
OilsOils, both mineral and synthetic, also cause severe problems in sewerage plants and must be transferred to licensed waste handlers. Waste oils, if carefully segregated according to type, are recoverable either as a recycled commodity, or as fuel oil.
Solid and Sludge Wastes
GlassGlass waste must be stored in a labeled robust waste bin separately from other solid waste for ease of recycling. Empty reagent bottles in good condition may be re-used within the laboratory after thorough cleaning and removal of old labels.
ResinsAs a general rule synthetic resins and resin components, whether fully cured or not, should not be mixed with general non-hazardous waste
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for disposal. They should be placed separately in labeled containers with appropriate labels indicating the possible hazards for disposal as special waste.
Safety and Environmental considerations for Laboratory Waste Disposal General Considerations:All potential waste streams that arise as part of laboratory operations needs to be assessed and an appropriate disposal route selected prior to it actually being generated.
Waste should be collected in a suitable container and labeled accordingly.
All generators of potentially hazardous wastes must ensure segregation, accurate and complete labeling and safe storage, transport, treatment and disposal of such wastes.
Wastes should be minimized where possible. Waste chemicals and solvents are stored in suitable areas whilst
awaiting collection and must not be accumulated. Wastes should be segregated and mixing avoided where possible, as
unexpected reactions may occur. (Note chemical Compatibility) If you are generating a large amount of one particular type of waste,
have a separate residue container for it. Ensure the container is not leaking and there is no spillage on the
exterior of the container. Untrained staff and students are not to handle hazardous wastes
and must not be given responsibility for them. Personal Protective Equipment should be a consideration when
handling chemical waste. Reference should be made to the Material Safety Data Sheet. Special collections can be made from the laboratory at the cost of
the unit and/or research group. Class 1 (Explosive) and Class 4 (Spontaneously Combustible) wastes
should follow special disposal procedures. Halogenated solvent wastes are to be collected in waste containers,
labeled as halogenated solvents. Halogenated wastes must be kept separate to other organic solvents as, for example, mixtures of acetone and chloroform can explode.
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Cyanide wastes must be placed in an appropriate waste bottle and the solution kept alkaline at all times
Dry chemicals should be placed in a drum (not more than 5L), labeled "Waste Chemicals for Disposal".
Strong oxidizing and reducing agents (chlorates, bromates, peroxides, nitrates, iodides, metal dusts, hypochlorites, etc.) should not be placed in this drum. Highly reactive substances such as amines, phosphorus compounds, acetic anhydride, acetyl- chloride should never be placed in general disposal containers. Follow safety instructions on the disposal of these reactive dry chemicals. They should never be placed with organic chemicals.
Always seek Guidelines for Laboratory Waste Disposal.1.3 Classify chemicals according to their properties
Storage of chemicals The primary purpose of this plan is to control health or physical hazards posed by chemical compounds during storage in the lab. Specifically, it is designed to:
1. Protect flammables from ignition; 2. Minimize the potential of exposure to poisons; and 3. Segregate incompatible compounds to prevent their accidental
mixing.
Note: Storage Begins with Purchasing - purchase minimum needed for
experiment do not “buy in bulk” to lower per unit costs (unless the “bulk” quantity is needed).
Limit the amount of chemicals stored to the minimum required. Initial & date chemical labels upon receipt.
Ranking Chemical Storage Groups: (From Most Hazardous to Least Hazardous)Group 1: Flammables Group 2: Volatile Poisons Group 3: Oxidizing Acids Group 4: Organic and Mineral Acids Group 5: Liquid Bases Group 6: Liquid Oxidizers Group 7: Non-Volatile Poisons Group 8: Metal HydridesGroup 9: Dry Solids
These groups fall under the following categories:
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Solvents - which include flammable/combustible liquids and halogenated hydrocarbons (e.g., acetone, benzene, ethers, alcohols)
Note: Store glacial acetic acid as a flammable liquid Inorganic mineral acids (e.g., nitric, sulfuric, hydrochloric, and
perchloric acids). Bases (e.g., sodium hydroxide, ammonium hydroxide) Oxidizers Poisons Explosives or unstable reactive chemicals such as peroxides.
Ensure that caps and lids on all chemical containers are tightly closed to prevent evaporation of contents. Store all hazardous liquid chemicals in drip trays that are chemically resistant.
Storage Based on Hazard Class Avoid storing chemicals on countertops or in fume hoods except for
thosebeing currently used.
Label all containers to which hazardous materials are transferred with the identity of the substance and its hazards.
Avoid exposure of chemicals to heat or direct sunlight. This may lead to the deterioration of storage containers as well as the degradation of the chemicals.
Use approved corrosive storage cabinets (constructed of chemically resistant components) for storing acids and bases.
Use flammable storage cabinets to store flammable liquids.
The following guidelines are provided for the safe storage of hazardous materials in accordance with their hazard classes: Acids
Segregate acids from reactive metals such as sodium, potassium, magnesium, etc.
Segregate oxidizing acids from organic acids, flammable and combustible materials.
Segregate acids from chemicals which could generate toxic or flammable gases upon contact, such as sodium cyanide, iron sulfide, calcium carbide, etc.
Segregate acids from bases.
Bases Segregate bases from acids, metals, explosives, organic peroxides
and easily ignitable materials.
Solvents (Flammable and Halogenated Solvents)
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Store solvents in approved safety cans or cabinets. Segregate them from oxidizing acids and oxidizers. Keep them away from any source of ignition (heat, sparks, or open
flames).
Oxidizers Store in a cool and dry place. Keep away from combustible and flammable materials. Keep away from reducing agents such as zinc, alkali metals, and
formic acid.
Cyanides Segregate from acids and oxidizers.
Water Reactive Chemicals Store in a cool, dry place away from any water source. Make certain that a Class D fire extinguisher is available in case of
fire.
Pyrophoric Substance (Materials which will react with the air to ignite when exposed, example: white phosphorus.)
Store in a cool, dry place making provisions for an airtight seal.
Light Sensitive Chemicals Store in amber bottles in a cool, dry, dark place.
Peroxide Forming Chemicals Store in airtight containers in a dark, cool, and dry place. Label containers with receiving, opening, and disposal dates. Periodically test for the presence of peroxides.
Toxic Chemicals Store according to the nature of the chemical, using appropriate
security where necessary. Know the properties of the chemicals used.
Chemical Storage - Incompatible Chemicals Certain hazardous chemicals should not be mixed or stored with other
chemicals because a severe reaction can take place or an extremely toxic reaction product can result.
The following incompatibility matrix and table contains examples of incompatible chemicals:
Acids AcidsOxidizin
Acids Alkalis
Oxidizer Poisonsinorgani
Poisons
Water reactiv
Organic
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Inorganic
g Organics
/Bases
s c organic
e solvents
AcidsInorganic
X X X X X X
AcidsOxidizing
X X X X X X
AcidOrganics,
X X X X X X X
Alkalis (Bases)
X X X X X X
Oxidizers
X X X X
PoisonsInorganic
X X X X X X
PoisonsOrganic
X X X X X X
Water reactive
X X X X X X
Organic solvents
X X X X X
X = Not compatible – do not store togetherA Designated Storage Place for Each Compound
Each stock chemical container should have a designated storage place, and should be returned to that same location after each use.
Storage locations can be marked on containers. Do not store stock supplies of chemicals on benchtops where they
are unprotected from ignition sources and are more easily knocked over. Only chemicals in use or of low hazard levels (e.g., salts and buffers) are permitted on benchtops.
Chemicals must never be stored on the floor, not even temporarily!
Do Not Store in Chemical Fume Hood Do not keep stock supplies of chemicals or waste in chemical fume
hoods where they clutter space, interfere with the hood’s airflow, and may increase the risk of a fire in the laboratory.
Seal All Chemical Containers All chemical containers must be sealed, including bottles used for
waste chemicals. Waste containers must remain sealed except when a worker is actually filling the container with chemical waste.
Alphabetical Only within Storage Groups Do not store chemicals in alphabetical order except within a storage
group. (Alphabetical arrangement of randomly collected chemicals
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often increases the likelihood of dangerous reactions by bringing incompatible materials into close proximity).
Keep chemicals Away from Sun and Heat Storage areas should not be exposed to extremes of heat or
sunlight.
Do Not Store Chemicals under the Sink Do not store any chemicals except bleach and compatible cleaning
agents under the sink.
Labels and Labelling (Label Chemicals Properly) Chemicals should be dated when received and when opened. If the
chemical is one that degrades in quality or becomes unsafe after prolonged storage, the shelf-life expiration date should also be included.
All containers of chemicals must be properly labeled. These include chemicals stored in their original containers, chemicals transferred to another container for storage, and chemical solutions prepared in the lab for non-immediate use.
2.0 DESIGN LABORATORY LAYOUT
2.1 Design layout for analytical space based on parameters
For any new construction or renovation of laboratory areas, consider health, safety and regulatory compliance issues regarding laboratory equipment, chemicals and parameters to be analyzed early in the design stage of the project.
There should be a visible separation between laboratory and non- laboratory space, for instance with different flooring.
Laboratory space should be physically separate from personal desk space, meeting space and eating areas.
Workers should not move across laboratory space or chemical storage places in order to exit from non-laboratory areas.
2.2 Preliminary consideration for design
Doors to laboratories should open outward and not be fire-rated unless necessary.
Slippery floors should be avoided. Equipment such as weighing scales, analytical machines such as
spectrometers etc should rest non vibrating floor bases.
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Entry ways should have provisions for mounting emergency information posters and other warning signage immediately outside the laboratory (e.g., on the door).
Each door from a hallway into a lab should have a view panel to prevent accidents to allow individuals to see into the laboratory in case of an accident or injury.
Laboratory areas with autoclaves should have adequate room to allow access to the autoclave and clearance behind it for maintenance. There should also be adequate room for temporary storage of materials before and after processing. Autoclave drainage should be designed to prevent or minimize flooding and damage to the floor.
Eating and drinking areas should be physically separate and conveniently located.
Allow for security of laboratory and materials. Consider the need for vented chemical storage areas or cabinets
for chemicals with low odour thresholds. Allow adequate ventilation. The location of fume hoods, supply air vents, laboratory furniture
and pedestrian traffic should encourage horizontal, laminar flow of air into the face of the hood, perpendicular to the hood opening. Hoods should be placed away from doors and not where they would face each other across a narrow space.
Laboratories using hazardous materials must have an eyewash and safety shower within 100 feet or 10 seconds travel time from the chemical use areas.
Flooring under safety showers should be slip-resistant. Fire extinguishers, safety showers and eyewashes should be
conspicuously labelled. Fire extinguishers appropriate for the chemicals and equipment
in use should be placed near the entrance of each laboratory.
2.3 Design biological laboratory layout A biological laboratory at a minimum requires the following: A full range of piped services such as deionized or reverse
osmosis (RO) water, Laboratory cold and hot water, A water distiller, A hand washing sink with emergency eyewash, A safety shower, A fume hood/chamber, A standard flammable storage cabinet, A refrigerator,
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A corrosive storage cabinet. Wet Laboratories: Biological Laboratories are essentially wet
laboratories of which their functions include working with solutions or biological materials. The analysts and researchers utilize benches, sinks, chemical fume hoods and cabinets. Generally, a wet laboratory is fitted out with a full range of piped services such as deionized or reverse osmosis (RO) water, laboratory cold and hot water, laboratory waste/vents, carbon dioxide (CO2), vacuum, compressed air, hand washing sinks, eyewash, safety showers, natural gas, telephone, local area network (LAN), lighting, and power. Any wet laboratory where biological specimens are used shall require an area to store wastes. Sufficient kneehole space shall be provided in each laboratory to accommodate chairs as well as other in use waste receptacles. Laboratories that use radioactive materials will require a lockable storage area for multiple radioactive waste containers including dry and liquid waste. Access to ice cubes is required for most biomedical research. Work areas and desk space require low bench space with kneeholes or adjustable, flexible desktop space. These areas may be used for a large number of computers requiring High Voltage AC, supplemental cooling, electricity, emergency power, uninterruptible power, and/or telecommunications / LAN.
Microbiological Laboratories: A microbiology laboratory is a more specific biological laboratory that deals with the qualitative and quantitative estimations of microorganisms as of interest in a given situation. This interest may be the need to assure the quality of products, safety in handling and consuming them, the probable spoilage they may undergo; or it may be to recognize the effective functioning of microorganisms in processing (fermenting) food. Products examined microbiologically may be water (potable and for other uses), foods & feeds, and non-food items. The tests performed in a food microbiology testing laboratory are mostly to examine the following parameters or microorganisms, but are not limited to what is given below:
Total plate count or viable plate count Coliforms and fecal (thermotolent) coliforms as a group Escherichia coli Staphylococcus aureus and their toxins Salmonella Listeria monocytogenes Bacillus cereus Yeasts & Molds Pseudomonas aeruginosa in water
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The testing may extend to the following microorganisms in specific situations where food is known to be vulnerable or is exposed to reservoirs of pathogenic microorganisms:
Laboratory facilities should also provide space for administrative activities and informal staff interaction. Administrative space should include offices for the laboratory personnel and their secretarial and support staff. Areas should be provided to encourage interaction and philosophical exchange of ideas between scientists. Interaction areas may include refreshment or break areas, copy centers, meeting rooms, corridors, and terraces.
Factors to be considered when designing a Laboratory is to effectively achieve the Laboratory Goals and Objectives
Quality of LifeThe laboratory should be designed for people who conduct analyses and provide them with a safe and pleasant work environment that leads to increased productivity: Direct natural light and view to the exterior, adequate work space, appropriate color, a coordinated and well organized layout, cafeterias, credit unions, bank teller machines, recreation facilities, shops, and child care facilities are some of the design features that will enhance the quality of life. These amenities should ether be in the facility or in close proximity.
Natural Light and Lighting: Laboratories and offices should be provided with natural light and views to the outside, as long as they do not conflict with functional requirements. Laboratory requires high quality lighting in terms of lighting intensity. The ability to control lighting in specialized laboratories or in spaces that use computers should also be considered.
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Noise: Noise sensitive areas include, but are not limited to, space where microscopy, microinjection or other procedures that require a high degree of manual precision or metal concentration are performed. Noise levels in laboratories are difficult to control because room finishes are generally hard and non-absorbent. Equipment such as chemical fume hoods, centrifuges, and vacuum pumps contribute to the high noise levels within the laboratory. Planning should isolate noise sensitive areas from noise sources wherever possible. Vibration: Vibration caused by equipment can adversely affect the quality of life in the workplace for personnel. Structural dampening to minimize vibration is required for sensitive instruments so that scientific research is not adversely affected. Some pieces of equipment that are vibration sensitive can be placed on a special vibration dampening table or close to more vibration stable parts of the building. Interaction: Exchange of ideas in a biomedical research facility is fostered by formal and informal communication, interaction and collaboration among labs of the same competence. In addition to the desired consolidation of branch level activities, an important requirement is a building planning concept that promotes informal encounters and communications among all of its occupants. Proximity to common facilities, such as conference rooms, rest rooms, break rooms, coffee areas and vending machines, mailboxes, clerical support services and supplies encourage casual encounters and facilitate interaction. Interaction areas should be shared spaces and these spaces should be designed to draw analysts out of their labs and offices from time to time. Careful design of circulation patterns and corridor spaces can also contribute to interaction between building occupants in all parts of a building. The designer should consider alternative informal interaction areas such as event areas at the end of corridors where analysts can talk together without using meeting rooms In addition, bulletin boards, directories and seating areas should be located in entrance lobbies or where there is cafeteria access. Conference rooms might open into these areas to encourage additional interaction. Another potential interactive space might be an exhibit area in a public entrance area that has adjacency to an auditorium, cafeteria or other public spaces. Flexibility: It is important that laboratory space and utility services be designed for flexibility so they can be readily adapted to accommodate future changes in research protocols. Laboratories require an enormous
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amount of capital to construct, and they should not be rendered functionally obsolete due to a minor change in state-of-the-art technology or research priorities. It is important that the laboratory have the ability to change without affecting adjacent research activities.
Capability: The laboratory building must be capable of providing all the utility services necessary for the scientists to conduct their research. It is equally important that provisions be made for future utility services to accommodate unanticipated demands brought about through improvements in technology or through changes in research protocols. Flexibility and capability can be said "to go hand in hand". Reserve capacity should be designed into the primary building utility systems to accommodate future levels of growth and change. Spare capacity should be designed into the building systems to allow researchers flexibility to add equipment and instrumentation as required meeting ever changing needs without compromising laboratory health and safety.
Expansion: In the context of master planning, future expansion is an important consideration in laboratory facilities. State-of-the-art research buildings must be designed to accommodate expansion. Establishing a framework for building systems which can be easily expanded and be consistent with the master plan is essential.
Laboratory development and layoutIt is important in developing a laboratory and preparing the layout to recognize the required work capacity of the laboratory, the number of staff engaged in testing, the services (electricity, water, gas) required and the mechanisms to control unintentional release of microorganisms to the environment as well as cross contaminations. Two layouts for a small capacity laboratory and an optimal capacity laboratory are described below:
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General guidelines for a small microbiological testing laboratoryWhere funds and human resource are limited, it is advisable to establish microbiological laboratories of minimum capacity, with the possibility of future expansion as demand and funds increase. Three essential separate works spaces need to be identified and an office space. Small laboratories will expect to have around four technical staff.
Let us take a microbiological testing laboratory with a minimal capacity of 70 sq. m. It will have a separate room in the vicinity which allows public access for receiving and storing samples. This room may be adjacent to the laboratory or some distance from it, depending on the general layout of the institution and its areas of public access. The sample receipt room may serve as a common facility for other testing laboratories (chemical etc). The space suggested for each activity in a small laboratory is as follows:
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Food testing Laboratory 25 m2
Changing/entry room 10m2
Media preparation room 10m2
Washing/decontamination room 10m2
Office 10m2
Interior passage 05m2
TOTAL 70m2 (Approx.)
FIG 1 - LAYOUT PLAN FOR A SMALL FOOD MICROBIOLOGICAL TESTING LABORATORY
The layout plan in (Fig. 1) shows an arrangement of the different areas used to carry out functions preventing contamination. There are locations for:
The main testing laboratory, A media preparation room, Glassware washing, An office, Changing room.
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FIG 2 - LAYOUT PLAN FOR WORK BENCHES IN A SMALL FOOD MICROBIOLOGICAL TESTING LABORATORY
A constructed workbench projecting into the middle of the laboratory, as indicated in the layout diagram in the figure above (Fig. 2). The proposed dimensions for the bench are 90 cm (height), 400 cm (length)) and 125 cm (width) with a sink, power outlets and gas outlets. The centre writing table in testing laboratory should be 100 cm x 100 cm x 75 cm (height).
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FIG 3 - LAYOUT PLAN FOR EQUIPMENT FOR A SMALL FOOD MICROBIOLOGICAL TESTING LABORATORYThe locations for equipment in the laboratory are given in Fig. 3
Important considerations for equipment installation• Locate and plan space required for heavy equipment, • Locate and plan space required for sensitive equipment and • Follow instructions for installation of equipment.
For example balances:
Should be located in separate room, protected from sudden drafts and humidify changes.
Temperatures should be at room temperature; this is especially important if building heat is shut off or reduced during non-working hours.
When not in use, the balance should be properly switched off, objects such as weighing dish removed from the pan and the slide door closed.
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Special precautions should be taken to avoid spillage of corrosive chemicals on the pan or inside the balance case; the interior of the balance housing should be kept clean.
Balances should be checked and calibrated periodically by a company service man or follow the relevant manufacturer's instructions as closely as possible.
The balance should be operated at all times according to the manufacturer’s instructions.
2.4 List of instrument common used in aquatic environmental analysis
Balances with different sensitivity: analytical, electronic, etc. pH meter, ion-selective electrodes, electro-conductivity meter, DO
a. Visual & Ultraviolet b. Infrared c. Fluorescence d. Atomic Absorption (AAS) e. Inductively Coupled Plasma (ICP) f. Atomic Emission spectrophotometer g. Mass Spectrometer
Total and Dissolved Organic Carbon Analyzer (TOC/DOC) Adsorbable/Extractable Organic Halogen Analyzer AOX/EOX) Gas Chromatographs (GC) with different detectors Ion-chromatograph (for anions and/or cations) High Pressure Liquid Chromatography (HPLC)
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2.0Sanitary inspection in conjunction with laboratory analysis and report preparation.
2.1 Sanitary inspection of water sources and laboratory analysisThe water supply source is the beginning of the drinking water system. Preventing source water contamination is the most effective means of preventing contaminants from reaching consumers. Source water protection also helps you to ensure the least expensive method is used for treatment of water. Hence, a sanitary inspection should be designed to assess the control of contaminants and determine the reliability, quality, quantity and vulnerability of the water source. The photograph below portrays the shallow well in the rural setup.
Collecting water in jerrycans and traditional pots. (Photo: Richard Adam)
Sanitary inspection and water-quality analysis are complementary activities. However it has been suggested that sanitary inspection should take priority over analysis, but the two should be done together wherever possible. The inspection identifies potential hazards, while analysis indicates whether contamination is occurring and, if so, its intensity. A sanitary inspection is indispensable for the adequate interpretation of laboratory results.
Sanitary inspections reports provide essential information about immediate and ongoing possible hazards associated with a community
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water supply, even in the absence of microbiological or chemical evidence of contamination. In addition, inspection reports of over a period of years provides a longer-term perspective and assists in the identification and minimization of risks caused by progressive deterioration in any aspect of water supply.
