塩化ナトリウム粒子を用いたフードからの漏洩濃度の測定

抄録

Concentration of NaCl aerosol released from a fume hood to the work place was measured at face velocities of fume hood up to 0.5m/sec. Influence on the release rate of aerosol was investigated, i. e. the movement of a worker in front of the fume hood and the flow rate of room air supply. Release of the aerosol was detected in work place when fume hood face velocity was lower than 0.4m/sec. The concentration of aerosol released to the work place increased with a decrease in the face velocity. On the other hand, the release was not detected at face velocity 0.5m/sec in any working condition, where the concentration in the air was less than 8×10^-12μg/cm³ per dispersion rate (μg/min), as the detection limit. This value was 1/4, 000 of the concentration which was estimated assuming that 1/10 of the aerosol quantity in the fume hood was released.