Cleaning work benches

Horizontal laminar flow clean air benches are not BSCs (Section 10.3.4). They discharge HEPA-filtered air across the work surface and toward the user. These devices only provide product protection. They can be used for certain dean activirie.s, such as the dust-free assembly of sterile equipment or electronic devices. These benches should never be used when handling potentially infectious materials. The worker can be exposed to materials on the clean bench. Horizontal clean air benches should never be used as a substitute for, i biological safety cabinet. 

This problem can be avoided by mounting utility outlets above the work benches. This method also has the advantage of keeping the benches clear of obstructions and easy to clean. Of course, exposed water pipes and electrical conduit do not have much esthetic value, and they are dust catchers as well. A coat of paint, however, both improves their appearance and makes cleaning easier. An even better solution is to box them in and cover them with removable panels. 

Electrical outlets can be installed in one of several ways. Small pedestals holding two or more outlets are often placed along the rear of wall-mounted work benches. They may also be put along the center of peninsulas or islands. Wiring is from below the countertop, which makes modifications difficult, just as with plumbing. While easy to reach, pedestals clutter the top and interfere with cleaning. 

After completing the experiments, clean the work bench and do not leave any hazardous chemicals unattended. 

Keep bench and work area clean and uncluttered. When you are finished using a chemical, put it back into storage and even if you are not finished with it, seal it back up with the cap or stopper. A clean work place makes things much faster, easier and safer. 

Below are two types of steam generators that you can build. The top one utilizes gas and the bottom one uses electricity for power. Every work bench needs steam. It is very safe for heating and very effective for cleaning glassware, etc. 

Fixtures within the room (e.g. work benches, chairs, equipment, etc.) should be kept to a minimum, and ideally be designed and fabricated from material that facilitates effective cleaning (e.g. polished stainless steel). The positioning of such fixtures should not hinder effective cleaning processes. Pipework should be installed in such a way as to allow effective cleaning around them and the presence of uncleanable recesses must be avoided. All corners and joints between walls and ceilings or floors are rounded, and equipment with movable parts (e.g. motors, pumps) should be encased. 

Some indication of a chemist s practical ability is apparent from the appearance of the working bench. This should always be kept clean and dry this is easily done if suitable wet and dry rags are kept at hand. Apparatus not immediately required should be kept as far as possible in a cupboard beneath the bench if it must be placed on the bench, it should be arranged in a neat and orderly manner. Dirty apparatus can be placed in a plastic bowl away from the working area until it can be cleaned and put away. Solid waste and filter papers must not be thrown in the sink. 

Consider that if 10 ml of a cell suspension is removed from a vessel it is replaced by 10 ml of air. It is therefore essential to reduce airborne contamination to a minimum. In an undisturbed room bacteria and fungal spores rapidly settle to the floor or the bench, and hence regular cleaning of the floor and bench with antiseptic solutions is required. The floor of the work room should be free of cracks and should be cleaned daily with a disinfectant solution. The work bench should be swabbed down before and after each use with a solution of 70% ethanol. This also serves to kill cultured cells which may have been spilt and hence prevents their transfer to other cultures (see 2.2). 

II.4 SEMIMICRO APPARATUS AND SEMIMICRO ANALYTICAL OPERATIONS The essential technique of semimicro analysis does not differ very greatly from that of macro analysis. Since volumes of the order of 1 ml are dealt with, the scale of the apparatus is reduced it may be said at once that as soon as the simple technique has been acquired and mastered, the student will find it just as easy to manipulate these small volumes and quantities as to work with larger volumes and quantities in ordinary test-tubes (150 x20 mm) and related apparatus. The various operations occupy less time and the consumption of chemicals and glassware is reduced considerably these two factors are of great importance when time and money are limited. Particular care must be directed to having both the apparatus and the working bench scrupulously clean. 

Inoculation Rooms. Frequently, separate rooms are used for work with bacteria, actinomycetes, molds, and sterility testing. High intensity UV lighting is commonly used when the rooms are unoccupied. These rooms generally have only work benches (or hoods) for easy cleaning. 

Researchers who worked in chemical laboratories 25 years ago will remember well that benzene was one of the common solvents used extensively, without any special precautions, for column chromatography and for general cleaning. Diethyl ether extraction of organic substances was carried out in laboratories equipped with gas hot water geysers, with ever lit pilot flame, and metals like lead, mercury, cadmium and arsenic were detected by carrying out flame test using Bunsen burners (mi the work bench. 

It is always desired and recommended that all cleaned glass apparatus not-in-use must not be allowed to accumulate on the working bench but should be stored away safely beneath the bench. 

Collection of the dust takes place via extracting walls, roof domes, moveable hoods or extraction work benches. An effective aid when collecting emissions are hot-air curtains which direct additional air into the cabin. The additional air used may be cleaned recycled extraction air, in order to economise on heating energy. However, it should be noted, that a portion of fresh air will still always need to be provided from the outside. 

Set up a clean working space, preferably with lower benching. Have an adjustable chair, set to a height such that you can look comfortably down the microscope with the back straight, but at the same time rest your arms on the bench or on specialized handrest, as this steadies the hands. 

Daily cleaning and disinfection of the interior of a safety cabinet is important. The tray under the work bench as well as the pre-filter contains spilled fluids. This area has to be cleaned and disinfected at least once a week wearing a P3 mask (see Sect. 26.4.1) and protective impermeable clothing. The pre-filters must be changed every 3-6 months the HEPA filters must be changed only after significant failme at qualification tests, repair being not possible any more. 

ALWAYS work on a clean laboratory bench surface, preferably glass ... 

Description of Operation The maintenance technicians remove and clean the solder pumps in accordance with the Standard Operating Procedure for the operation. The pumps are cleaned on a work bench in the tech area by scraping with metal spatula and brushing with a wire brush. 

General Observations Good housekeeping in the area, no visible indications of surface contamination. No signs of smoking or eating. Two desks had coffee cups. Scrapers and wire brushes not cleaned after use, but they are only used for the pump clean and they are kept in a small metal cabinet under the work bench that is dedicated to their storage. 

Personal air samples will be taken for both technicians. Two cassettes will be taken for each tech one while the pump is being cleaned on the work bench, and another during other operations where the exposures are not expected to be significant (e.g., pump removal and le-installation). 

Wipe samples will be taken on the work bench before pump maintenance (2 wipes) and post-clean after pump maintenance (5 wipes) on the wave solder machine at one or two locations before it is opened for maintenance (2-4 wipes) and after maintenance is complete (2-4 wipes) on the desk closest to the work bench (3 wipes) on the fingers of the technicians after removing gloves and washing hands (2-4 wipes). 

A typical thermogravimetric system is illustrated in Figs. 7.2 and 73, based on the classical, high-precision instrument, the Mettler Thermoanalyzer, first described in detail by Wiedemann in 1964. The left top sketch in Fig. 72 shows a view of a basic thermoanalyzer installation. The center table provides space for the high temperature furnace, the balance, and the basic vacuum equipment. The cabinet on the right houses the control electronics and the recorder. On the left is the work bench and gas cleaning setup. 

In order to achieve a high level of product safety it is well known that good work practices in the bench are necessary, and having a clean environment and proper work clothing are of vital importance. Knowledge about the interaction between air movements and the dispersion of contaminants plays an important role. Wake regions and vortex streets can easily be formed behind obstacles. 

Any cleaned portion of the Vitreosil must not be touched with the fingers before being worked. When using a bench flame, if the part being handled is subsequently to be worked, the piece of equipment must be re-cleaned before this further work is carried out. For this, cotton-wool dipped in alcohol is very useful—after the piece has been allowed to cool. 

Allocate adequate clean bench space for doing the work, so that equipment can be laid out in an uncluttered way. 

Place a clean sheet of aluminum foil on a bench top work area. Carefully remove each slide from the slide holder. Wipe remaining alcohol around the periphery of the tissue with Kim-wipe and place it on the clean sheet of aluminum foil. 

Finally, in a concluding paper Dr. Jorg Thommes considers enzyme recovery in Fluidized Bed Adsorption as a Primary Recovery Step in Protein Purification . As important as it is to track down new enzymes and selectively modify them, it remains equally important to actually make them available in the flask on the bench in adequate quantities at low cost with sufficient purity. Recovery is of central significance in this respect. Fluidized bed adsorption combines the process steps of cell separation, concentration and primary cleaning in recovery work. The procedure can also be excellently transferred from the laboratory to the pilot scale. 

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