Specifications

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4.1.5 Smoke Tubes
Smoke tube testing was conducted to visualize the effectiveness of the general exhaust
ventilation in the dispensing area. The smoke tube was activated at intervals of one foot up to
approximately seven feet from the exhaust. The ceiling mounted exhaust duct opening was
located approximately seven feet away from the dispensing station.
4.1.6 Strategy
Direct reading colorimetric tubes with hand held pump and treated silica gel tubes with low flow
pumps were used. The original intention was to sample from 7:30 am to 3:30 pm and the
sampling equipment was all set up waiting for the first biopsy of the day to appear, however, the
first two procedures did not yield a biopsy and therefore the sampling day was shortened.
The colorimetric detector tubes acted as personal samples since they were drawn in the breathing
zone of the worker. The silica gel tubes were collected as environmental (area) samples. For the
purposes of this study it was not practical to set the pumps and silica gel tubes on the nurses
since it was often a different nurse that dispensed the formalin. The nurse that dispenses the
formalin was the nurse that was in the OR where the biopsy was taken. If the unit had been
attached to one nurse for the duration of the shift the data would represent only one exposure to
formaldehyde. Since the units were set up near the formalin dispensing station they represented
a worst case scenario.
4.2 Nitrous Oxide
4.2.1 Equipment
• Bacharach Medigas Model 3010 Nitrous Oxide Meter P/N 19-7109.
This machine was a new, hand held, infra-red (IR) analyzer that can be used for personal
sampling. The unit can be worn on the waist belt and a small air sampling tube can be secured
on the back and leading to the breathing zone. Several discussions occurred between the various
Bacharach offices in Canada, United States and England concerning the operation and accuracy
of the machine. The machine was developed in England and discussions also occurred with the