[Formaldehyde-reducing efficiency of a newly developed dissection-table-connected local ventilation system in the...

In compliance with health and safety management guidelines against harmful formaldehyde (FA) levels in the gross anatomy laboratory, we newly developed a dissection-table-connected local ventilation system in 2006. The system was composed of (1) a simple plenum-chambered dissection table with low-cost filters, (2) a transparent vinyl flexible duct for easy mounting and removal, which connects the table and the exhaust pipe laid above the ceiling, and (3) an intake creating a downward-flow of air, which was installed on the ceiling just above each table. The dissection table was also designed as a separate-component system, of which the upper plate and marginal suction inlets can be taken apart for cleaning after dissection, and equipped with opening/closing side-windows for picking up materials dropped during dissection and a container underneath the table to receive exudate from the cadaver through a waste-fluid pipe. The local ventilation system dramatically reduced FA levels to 0.01-0.03 ppm in the gross anatomy laboratory room, resulting in no discomforting FA smell and irritating sensation while preserving the student's view of room and line of flow as well as solving the problems of high maintenance cost, sanitation issues inside the table, and working-inconvenience during dissection practice. Switching ventilation methods or power-modes, the current local ventilation system was demonstrated to be more than ten times efficient in FA reduction compared to the whole-room ventilation system and suggested that 11 m3/min/table in exhaust volume should decrease FA levels in both A- and B-measurements to less than 0.1 ppm in 1000 m3 space containing thirty-one 3.5%-FA-fixed cadavers.