Laboratory chemical hoods: a historical perspective.
A historical review of laboratory fume hoods leads to a consideration of the current status of structural design, operating characteristics (with special reference to face velocity), safety (relative to standardized test results), energy conservation, and certification methods. Noteworthy are (1) the increasing complexity of instrumentation designed to assure full safety function plus airflow modulation to minimize energy consumption; (2) the extreme plasticity of accepted and recommended face velocity values; (3) the insensitivity of standardized hood test protocols to variations in face velocity; and (4) a serious lack of correlation between operator risk, face velocity, and standard hood test results. Safety considerations lead to the selection of laboratory fume hoods having the highest demonstrated containment capability. This is in spite of the fact that most hood operations have a low hazard rating. Energy savings could be realized if the face velocity of each hood could be modulated to match the risk associated with the work being conducted.
First
Melvin W
MW
Department of Environmental Health Sciences, Harvard School of Public Health, 677 Huntington Ave., Boston, MA 02115, USA. mfirst@hsph.harvard.edu
D000392:Air Movements; D002568:Certification; D003247:Conservation of Natural Resources; D004736:Energy-Generating Resources; D017408:Guidelines as Topic; D006801:Humans; D007753:Laboratories; D016272:Occupational Health; D012449:Safety; D014691:Ventilation / Q000295:instrumentation* / Q000592:standards