Specifications

16
5.1.3 Smoke Tubes
The effectiveness of the general exhaust ventilation at removing the formalin vapours from the
dirty core area was tested using a smoke tube. The formalin dispensing station spigot was
located approximately seven feet from the ceiling-mounted exhaust grill in the dispensing room.
At one to three feet from the exhaust the smoke was drawn quickly into the exhaust, at four feet
the smoke lingered for a few seconds but it was still drawn to the exhaust; at five feet the general
exhaust had little or no effect on the smoke. There was no effect on the smoke when it was
tested right under the spigot of the formalin dispensing station.
According to the hospital ventilation system balance report from June 2000, the exhaust in the
formalin dispensing area had a flow rate of 1518 cfm.
5.2 Nitrous Oxide
5.2.1 Miran
Miran (area) data was collected for 8 Deliveries. No Miran data was collected for Delivery 5
because there was not enough time to move the machine from the adjacent room where Delivery
4 was in the final stages of delivery and set it up in the Delivery 5 room.
Deliveries 1, 2, 4, 5, 6, 7, 8, and 9 had a minimum and maximum readings of 2.7 ppm and 312.6
ppm. Delivery 3 had a minimum reading of 2.7 ppm and a maximum of 259 ppm. The means
for the deliveries ranged from 13.5 ppm to 194.5 ppm. In general, the Miran data fluctuated
wildly between 2.7 ppm and 312.6 ppm. It is important to note that once the values were
converted from volts (from Telog) to ppm, using a response curve generated by the WCB OF BC
laboratory, the Miran gave readings between 2.7 and 312.6 ppm. This means that the values
reported as 312.6 ppm may be greater than this value. Graphs of the Miran data can be found in
Appendix 6 of this report.