Do not be fooled by complacency or bad habits. No matter how much smoke there is it is dangerous. The photo's attached were taken at small kitchen fire that was actually extinguished before the arrival of the first due units. An elderly occupant that was unable to escape the structure was trapped on the second division in a bedroom. The ladder company quickly threw a ladder to the second division and brought the occupant down the ladder. The moderate smoke condition was ventilated and readings were taken using the HCN meter. At the time metering began the first division had a fair amount of natural ventilation that had occurred, so readings did not exceed 7ppm which is just about the department's action level of 5ppm. The second division saw higher numbers that were as high as 22ppm. These readings were taken once the fans were started and after natural ventilation had a chance to remove some of the smoke. Imagine what the levels were while the elderly occupant was waiting to be rescued. By looking at the photos it is hard to imagine numbers this high. This is only stresses the importance of utilizing SCBA and monitoring before removing it. Do not commit into the dangerous smoke filled environment because it doesn't look that bad, because looks are deceiving.
CLOSE CALL 2
At a recent incident 2 City firefighters were taken to the Hospital with the possibility of Hydrogen Cyanide (HCN) exposure. A policy was in place to avoid this issue which was not followed. One of the reasons I’m sure was the size of the fire. We were on the smallest kitchen fire you could ever have. Very little smoke and the fire only left the stove and exposed the cabinet directly above. I don’t even think the ceiling was sooted up. It was one of those fires that we would have had cleaned up and been back at the station in a few minutes in days past.
With that established we have been running a HCN detector with the Township for close to a year. We typically run the unit though with a CO monitor after knockdown to make sure air quality is good enough to remove our masks. In this case we found High levels of CO over 100 ppm and HCN near 50 ppm in the building. With the IDLH of HCN being around 4 and the fire being out for 10-15 minutes already you can see where we were confused. We already had a Gas Powered Honda PPV fan in the front door ventilating so we gave it more time and sent a few guys in packs to the second floor to begin to strategically open windows. The two guys who had been on initial attack and following had removed their masks were seeing all this from outside and reported feeling a little nauseous. They were checked out by medics and as a precaution transported to the hospital to be checked out. Again there was absolutely no visible smoke in the structure at the time they removed their masks. They were later released with no ill effects.
We learned while still on the scene that when the fan was started in this case the choke was left partially on. You couldn’t tell as the fan was not sputtering and appeared to be running normally. With the readings not really coming down with close to 30 minutes of continuous ventilation already under our belt, we decided to put one of our electrical fans in the doorway in a PPV configuration to see if we could get the property ventilated. The levels slowly began to go down on the first and second floor but we were still finding pockets of higher readings. I opened up a small bathroom that had been closed from the start and got a quick reading of over 20 ppm. This home approximately of 2500 square feet had a basement with a secondary stair with Bilco doors. This door had been opened early on yet the door to the basement had been closed. As everyone who has vented a house knows this didn’t let air from either operation push into the basement. We were still getting readings of HCN near 40 ppm down there. Once we made sure that we had the door open and an exhaust from the basement it took around 10 minutes to get the area totally cleared out allowing us to clear the scene. This would have been one of those events that we would have cleared in 20 minutes and gave back to the family to occupy prior to using our HCN Detector.
As you can expect we had a lot of questions resulting from this call. To try to get a better idea of what had happened we took our fan down to our training building to run a few tests. First, we took readings of both CO and HCN and got 0’s. We then ran the fan in a PPV configuration into the space at full throttle for 15 minutes and took readings. We got really no readings on HCN and 17 ppm on the CO meter. We then ran the same fan at about half choke at full throttle for 15 minutes. Following this time we took a second set of readings. The HCN was up to 21, which is 5 times the IDLH number and the CO was at 96 which is also above what is acceptable for any length of time. Our monitors were located approximately 15 feet inside the multi room structure, one room past the room the fans were directly charging. We had one window open at the back side of the space with good air flow from the vent.
In closing I have been doing this job for over 25 years. I have choked on my fair share of smoke over that time. I was even taught to breath off the nozzle in my early years. Since we began using this detector it has really opened my eyes to the prevalence and pervasiveness of this gas. It doesn’t seem to be very predictable to date. All I can tell you is that we have been breathing it more than we thought over the years.
