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microorganlsins currently used In biotechnologic applications are debilitated, 
or "crippled" through genetic manipulation such that their ability to 
reproduce outside of a laboratory environment is severely curtailed. None of 
the organisms in current use have been shown to cause Infection or disease in 
persons using biotechnologic techniques. Recent risk assessments suggest that 
the likelihood of infection by altered microorganisms is minimal. 
Despite those reassurances, probabilistic arguments have been developed that 
workers engaged in industrial applications of biotechnologies may be colonized 
8 9 
or infected by modified organisms. * 
The primary defense against colonization or infection of biotechnology workers 
will be provided by strict physical containment of genetically altered 
5 
organisms. Development of proper work practices and educational programs 
for workers is also of great Importance in reducing the likelihood of 
occupational exposures. In the development and capitalization of industrial 
biotechnologies, exposure control and worker protection should be given as 
great emphasis as process integrity and product development. Experience 
gained by NIOSH in other sectors of the chemical and pharmaceutical 
manufacturing industries Indicates that preplanned maintenance is also a 
central aspect of exposure control; facilities for containment of altered 
organisms should periodically, in accordance with a strict timetable, be shut 
down for scheduled examination and repair. Procedures for evaluation of 
facilities and for validation of the Integrity of physical containment should 
be developed at the outset as an integral component of facilities design. 
A second defense against colonization or infection of biotechnology workers is 
provided by "biological containment". Such containment will be achieved 
[ 514 ] 
