Angled sash modification of vertical sash fume hood.
Am Ind Hyg Assoc J 1986 Jul; 47(7):A-432
A fume hood in a pathology laboratory was redesigned to protect the operator's face from irritating concentrations of formaldehyde (50000) and other fluids during the performance of visually demanding tasks. The modified hood window had two sheets of clear acrylic, fitted with rubber strips at the sides. The sheets were hinged at the top and center and attached to the hood walls by sliding bolts at adjustable sash heights. The author recommends a clearance of at least 6 to 9 inches between the center hinge and the back wall, and selection of hood sash openings to prevent the back flow of contaminants out of the hood (recommended face velocities are 100 to 125 feet/minute). Before modification of the fume hood, laboratory personnel were exposed to formaldehyde concentrations exceeding the NIOSH recommended standard (1 ppm). The modified hood keeps exposures at or below analytical detection limits.
NIOSH-Author; Exhaust-hoods; Ventilation-hoods; Laboratory-equipment; Occupational-exposure; Eye-irritants; Eye-protective-equipment
American Industrial Hygiene Association Journal