Containment cabinets, primary

Laboratory rooms intended for toxic work should be provided with adjacent shower and change facilities. The layout must not require freshly showered personnel to track back through the area that they might have just contaminated. All drains, including those in laboratory floors, should have deep traps and be directed to a toxic sump. Airlocks will help prevent toxic fumes from spreading to non-toxic areas in the event of a failure of a primary containment cabinet. Check valves in the incoming water lines will prevent contamination of potable water supplies when pressure is lost. 

Physical containment of biohazards is achieved through the use of primary and secondary barriers. Primary barriers, the first line of defense against the release of a biohazardous agent, are the measures used to contain the experimental material, and include both techniques and equipment. In the context of this chapter, however, they refer to the use of items of equipment, particularly safety cabinets. Primary barriers are used to provide physical separation of the worker and experimental materials to prevent injury to the worker, provide physical separation of the experimental work from the environment to prevent contamination of the work, and control the release of aerosols created by the work which could pose a hazard for the researcher. 

Centers for Disease Control and Prevention and National Institutes of Health. Primary Containment of Biohazards Selection, Installation and Use of Biological Safety Cabinets. Washington, DC U.S. Department of Health and Human Services, 1995 (available on http // www.niehs.nih.gov/odhsb/biosafe/bsc/bsc.htm)... 

Class UB2 The Class 11B2 BSC is a total-exhaust cabinet no air is recirculated w ithin it (Fig. 10.97). This cabinet provides simultaneous primary biological and chemical containment. The supply blower draws in room air or outside air at the top of the cabinet, passes it through a HEP,IV filter, and down into the work area of the cabinet. The building or cabinet exhaust system draws air through both the rear and front grills, capturing the supply air plus the additional amount of room air needed to produce a... 

Databases are electronic filing cabinets that serve as a convenient and efficient means of storing vast amounts of information. An important distinction exists between primary (archival) and secondary (curated) databases. The primary databases represent experimental results with some interpretation. Their record is the sequence as it was experimentally derived. The DNA, RNA, or protein sequences are the items to be computed on and worked with as the valuable components of the primary databases. The secondary databases contain the fruits of analyses of the sequences in the primary sources such as patterns, motifs, functional sites, and so on. Most biochemical and/or molecular biology databases in the public domains are flat-file databases. Each entry of a database is given a unique identifier (i.e., an entry name and/or accession number) so that it can be retrieved uniformly by the combination of the database name and the identifier. 

Exhaust air from primary containment devices (fume hoods, safety cabinets or other) shall be appropriately treated by filtration using a high efficiency particulate air filter (HEPA), or by adsorption, absorption, reaction, incineration, or dilution used individually or in an appropriate combination. If HEPA or charcoal filters are used, these must be installed and operated to permit decontamination, maintenance, and replacement without exposing personnel or causing contamination of the environment. 

The facility must be designed to control access. Signs should designate restricted areas. Clothing requirements for entry should be identified. There should be directional air control with adequate ventilation rates. Primary containment equipment such as chemical fume hoods, a Class I or Class II (Type B) biological safety cabinet, or a glove box system should be available for use with known or suspect chemical carcinogens or other toxic substances. 

The water is treated with UV radiation for primary disinfection, then chlorinated for secondary disinfection. An applied chlorine dosage of only about 1 mg/L is necessary. The entire water treatment system is housed in a 2.97 m (32 fU) building. The UV disinfection system consists of six irradiation chambers, two control cabinets with alarms, chart recorders, relays, hour-run meters, lamp and power on-lights, six thermostats, electrical door interlocks, mimic diagrams, and six UV intensity monitors measuring the total UV output. Each irradiation chamber contains one 2.5-kW mercury vapor, medium-pressure arc tube, generating UV radiation at 253.7 nm. 

Biological materials to be removed from the Class III cabinet or from the Biosafety/Laboratory Containment Level 4 laboratory in a viable or intact state are transferred to a nonbreakable primary container and then enclosed in a nonbreakable, sealed secondary container. This is removed from the facility through a disinfectant dunk tank, fumigation chamber or an airlock designed for this purpose. 

A Processing Tank Containing Cell-Free Supernatant Aseptic Sample Port 9 C Cabinet (negative p ssur Primary and HEPA Filters 14... 

PRIMARY CONTAINMENT A system of containment which prevents the escape of a biological agent into the immediate working environment It involves the use of dosed containers or safety biological cabinets along with secure operating procedures. 

Equipment is considered the primary barrier for protection of the employees. Items such as biosafety cabinets, safety centrifuges, enclosed containers, impervious work surfaces, autoclaves, foot-operated sinks, and other equipment specifically designed to prevent direct contact with infectious organisms or with aerosols must be available. Personal protective equipment can also be considered as an effective secondary barrier if engineering controls are not sufficient. These latter items can include, at minimum, a lab coat or wrap-around gown, possibly gloves, masks, or respirators, goggles, and head and foot covers. 

During the preparation of hazardous drugs, use a ventilated cabinet to reduce the potential for occupational exposure. Performance test methods and criteria for BSCs may be found in Primary Containment for Biohazards Selection, Installation and Use of Biological Safety Cabinets, second edition, CDC/NIH, 2000. A current field certification label should be prominently displayed on the ventilated cabinet per NSF/ANSI49. 

FIGURE 7.3.4.1 Components of a HEPA Filter, (a) Borosilicate glass woven filter with aluminum separators (small folds) and (b) HEPA filter mounted in a wooden box. (From Figure 1 in CDC/NIH, Primary Containment for Biohazards Selection, Installation, and use of Biological Scfety Cabinets, 3 edition, 2007 available at http //www.cdc. gov/od/ohs/biosfty/primary containment for biohazards.pdf.)... 

Safety Equipment Enclosed containers, biological safety cabinets, and personal protection equipment are the main kinds of safety equipment. The primary roles are containment and barriers. Safety containers prevent the release of unsafe substances during normal activities and operations. An example is a safety centrifuge cup. 

Many so-called cabinet tests are used to detect lot-to-lot variation of materials. Cabinet tests involve exposure of a material to an aqueous fog that may contain a variety of corrosive species (e.g., chlorides, sulfates), either singly or in combination. The exposure conditions (e.g., temperature, solution pH, solution specific gravity, fog delivery rate, position of specimens) are carefully specified and controlled. However, extensive efforts to correlate cabinet test results with those of service performance tests for many materials, including steel, have failed. The inability of the cabinet to reproduce the exposure conditions experienced in service is the primary contributor to that limitation. The unique interplay of the environment with the relatively fragile passive film on steel makes proper selection of exposure conditions mandatory. Standardized cabinet tests that could be adapted for quality control of uncoated steel are described in the following standards ... 

From Figure 1 in CDC/NIH, Primary Containment for Biohazards Selection, Installation, and use cf Biological Safety Cabinets, 2009 http //www.cdc.gov/biosafety/pubUcations/bmbl5/BMBL5 appendixA. pdf, (accessed Dec 2014). 

Containment BLl-LS level. Cultures of viable organisms containing recombinant DNA molecules are to be handled in closed systems or other primary containment equipment. An example of required containment is a biological safety cabinet containing a centrifuge used to process recombinant DNA culture fluids. The purpose of containment is to reduce the potential for the escape... 

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