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BIOSAFETY


fitted with self-closing devices and interlocking.


The input and output of material from the


laboratories should be via barrier-type terminal boxes – boxes placed on the wall with two ports, so that the transfer material does not jeopardise the room air quality.1 For the waste outlet, autoclave type barrier systems should be used. BL-3 laboratories should be provided with a double door autoclave.


Figure 3: Signaling gateway to BL-3 laboratory.


to open observing the flows of laboratory areas to prevent accidents. Lever-type handles should be used to enable the doors to be opened without the use of hands. Environments containing large equipment will need to have doors or removable panels with leaves, that are width compatible with the size of the equipment, for entry and exit of the room.


In BL-3 laboratories, doors should be


considered as safety devices that prevent the entry of unauthorised people into areas of risk, and should only open after deployment of an identification card or other access device. The windows should be set high, to provide natural light and visual contact with the outside and should be located at least 1.10 m above floor level, to allow for the installation of benches or desks. In BL-3 areas the windows need to be properly sealed with safety glass.


Countertops, sinks and furniture Countertops for work undertaken in a standing position should be at a height of 0.90 m and counters for tasks undertaken in a sitting position, should be set at a height of 0.75 m with a minimum depth of 0.70 m or with dimensions suited to specific equipment. Laboratories should be equipped with at


least a double sink for washing and decontamination of materials and sinks for hand hygiene. The furniture needs to be ergonomic,


modulated and constructed with impervious surfaces that are resistant to chemicals, have no recesses and corners with latches and handles to allow for easy cleaning and maintenance.


Control barriers Control barriers include equipment and operating methods that seek to control the environmental conditions within closed and restricted areas, and to minimise the chance of contamination. Access to the laboratory is through barriers such as antechambers or an airlock locking system with double doors


Facilities The facilities areas need be designed to facilitate maintenance and to allow for flexibility of relocation or expansion. Facilities gases (compressed, liquefied or cryogenic) may have features that involve potential risk. Storage areas for gas cylinders should be outside the building, with easy access for maintenance, supply and with adequate ventilation. In BL-3 areas it is mandatory that the supply lines of compressed gases are equipped with HEPA filters. Air treatment facilities also need to meet


local regulatory requirements. Biological safety cabinets must have a duct to the outside of the building, with its tip sited above the highest point of the building and that of any neighbouring buildings, away from inhabited buildings and air intakes of the HVAC system (See Fig. 2). For BL-3 laboratories the installation of


exclusive use air treatment facilities is mandatory, equipped with HEPA filters in the exhaust duct without recirculation of air in the room or any other area of the building. The air flow must always be directed from areas of lower potential risk to the areas of greatest risk of contamination. The system must also be able to maintain an internal static pressure in the laboratory that is lower than that of surrounding areas (negative pressure). It also needs an automatic control system, fitted with an alarm sounder that is triggered in the event of a system failure. Physical facilities will also need to comply with the safety regulations of the local fire department and standards. The fire protection system should contain appropriate equipment with alarms, detectors and extinguishers which are all suitably located and marked. In BL-3 areas escape routes and


‘An accurate survey of the programme requirements is the first consideration for the architectural design of BL-3 laboratories.’


emergency exits must have direct access to the outside area and need to have an international biohazard symbol on the access door to the laboratory (See Fig. 3). This should also contain appropriate information on the microorganisms that are being handled, with their respective risk classes, the name of the researcher and a contact telephone number.


Decontamination and waste disposal A location for temporary storage of waste, before disposal, should also be considered. In BL-3 laboratories it is mandatory that the environment is equipped with a system that allows for disinfection and gas sterilisation via a physical autoclave barrier (double door), located between the support and containment areas.


Final considerations To properly design a laboratory that meets specific standards of work, it is necessary to know the biosafety level that will be adopted. For BL-1 and BL-2 levels of biological containment, a good functional planning of space, coupled with good laboratory practice, is sufficient. For BL-3 or BL-4 levels of biological


containment, where the infectious agents handled in these spaces the adoption of the requirements of levels BL-1 and BL-2, as well as the use of containment booms and equipment biosafety is necessary. Procedures undertaken in laboratories without the appropriate biosafety can have serious implications to humans and the environment. An accurate survey of the program


requirements is the first consideration for architectural design of BL-3 laboratories, which should detail the activities to be undertaken in each room, as well as a list of equipment to be used. These should take into account the specific requirements of containment areas too – such as purity, circulation and internal air pressure – and the requirements of environmental and acoustic comfort, lighting, materials, finishing, electrical installations, liquid and specialty gases.


References 1 Bicalho FC. 2010. A arquitetura e a engenharia no controle de infecções. 1a Books.


. ed. Rio de Janeiro: Rio


2 Vieira VM, Salgado MS. Indicadores da margem de incerteza das decisões arquitetônicas para laboratórios NB3 a partir de estudo de casos. Gestão e Tecnologia de Projetos 2008; 3(2) 78-105. Disponível em:www.arquitetura.eesc.usp.br/ jornal/index.php/gestaodeprojetos/article/ viewfile/78/95 Acessed on 27 July 2012.


3 Silva FH. L. A. Equipamentos de contenção. 1996. In: TEIXEIRA, P. (org.). Biossegurança: uma abordagem multidisciplinar. Rio de Janeiro: Fiocruz, p. 163-189.





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