Responding to a carbon monoxide alarm.

Dispatch

As soon as emergency rescue personnel or an HVAC company gets a call, trained professionals need to be ready to respond.  When the call concerns a home alarm of some type, dispatchers and HVAC technicians around North America have had to determine if it is a:

1.)    Smoke alarm or a CO alarm.

2.)    Where the people are calling from (a house on fire is no place for phone calls)

3.)    Has anyone passed out, vomiting or showing any other CO poisoning signs

4.)    Does the CO alarm have a reset button?  Has it been reset?  Are you still calling from the house?

Instruction must take place immediately as verbal questioning warrants.  If they haven’t left the building and the alarm has sounded again after reset, they should do so immediately if physically possible.

If one or more of the people in the building have headaches or are vomiting or showing any other physical indications of CO poisoning, they should all get to fresh air immediately if possible.

If someone has fainted or is unconscious and/or cannot be moved outside the affected area, windows and doors should be opened, especially in the room where the unconscious victim is.  Get everyone outside.

Instruct them not to go around opening windows, doors and turning off appliances if everyone can get outside immediately. 

Someone in a potentially contaminated environment should probably not be told to go around opening doors and windows risking further exposure.

Ventilating a structure may make it impossible to determine if CO was indeed present as well as increase the difficulty in identifying the source.

Go to a neighbor’s house if possible.  The calling adult should wait for the first response team in front of the building.  Complete cooperation with the first responders is vital.

Many times the service department of a regulated gas utility company is notified in direct phone link to all 911 CO alarm calls.  The cooperation between the gas utility companies and the fire departments in most areas has been professionally responsive.  This same cooperative effort appears to be absent in many rural areas where non-regulated fuel supply exists.

FIRST RESPONSE

There are many possible sources of CO in a building.  When you respond to CO, the protection of the inhabitants and all response personnel is predominant.  Your emergency response team must share in and understand the importance of each investigative step.  Each team member should have his or her own test instrument.

Before testing the buildings’ air for carbon monoxide we must have an instrument calibrated to manufacturers specifications and turned on outside the building. 

(Auto zero instruments will register increases above this false zero start.)  If you are using the Monoxor IIâ, you may manually zero the display.  Keep in mind, this is only to be done in environments where no CO is in the air and only needs that adjustment every few months.  There is little drift in the instruments display if we understand its’ boundaries of operation and we’re careful and observant during its’ use.

1.                  Cylinder, Calibration Gas (For CO calibration, use Bacharach P/N 24-0492. Recommended flow is 2-3 liters/minute at approx. 10 psi)

2.                  Regulator, P/N 51-2974

3.                  Tubing, P/N 03-6351

4.                  Tee, P/N 03-5532

5.                  Flow meter, P/N 06-6163

We have established our outside air reference and we record it.  If the calling consumer is not waiting in front of the building, our decision to enter becomes immediate: There may be someone inside.

If the caller is waiting for you outside the building, find out about all other inhabitants’ location and general health conditions while another one of your team enters the building, CO measuring device in hand.

Before entering any building on a CO or CO alarm call, some emergency responders are required (or it is local department policy) to wear self-contained breathing apparatus (SCBA).  In some jurisdictions, it is not uncommon to find SCBA’s worn if the inside atmosphere contains over 35 PPM or even 50 PPM.

Inside we are measuring air and looking for people or animals.  Confusion is one of the symptoms of CO poisoning and even though the caller informed you everyone was out of the building, our duty is to check again.  Record inside measurements.

Outside, our team member is still with the caller. Obviously, we would first address those most sick and administer oxygen and call for back-up support if needed.

If none of the building inhabitants are demonstrating debilitating CO poisoning symptoms, obtain a breath sample from whoever has been in the building the longest time and perhaps the healthiest (non smoking) person in the group.  We attach the Breath Analyzer Module to our Monoxor IIâ.

Have the subject inhale completely and hold breath for 15-20 seconds.  Subject should exhale about one-half of breath into the atmosphere and then, following instrument instructions, breathe the remaining breath into the mouthpiece of the BAM.  The balloon should be inflated in this manner until it reaches approximately 5” in diameter.

The expired breath will move through the test instrument and concentration in PPM will be displayed on the digital display.  This reading is not COHb %.  We have to convert that PPM measurement.  The accompanying chart will demonstrate the approximate equivalencies of PPM and COHb%.  If a poisoning of any degree is verified, your procedures for poisoning response should be followed.

Smokers may record a variance of COHb.  This range usually is within 2% to 6% COHb.  However, the amount of measured COHb in a smoker depends upon how soon after a cigarette smoked the sample is taken and how heavy a smoker the victim is.  Higher measurements may occur if a test is taken within the first ten minutes after a cigarette as opposed to one hour or more.  The amount of cigarettes per day and smoke actually inhaled also has an effect on this measurement.  (Often times in Bacharach seminar, a smoker volunteers for this breath test and the measurement is above 6% and not unusual to be over 10%)

It is suggested that samples be taken from several people in the building.  Record all measurements.

People living in urban areas where auto exhaust is high and background CO measurements regularly record above 9 PPM may also have breath samples around 2% even if they are non-smokers.  The human body produces some CO naturally; about ½ to 1% is a normal reading for a non-smoker who lives in fresh air.  If the average healthy person inhales 70 PPM for around 3 hours, a measurement should find around 10% COHb.

Once you have quantified the CO health of all people, your next steps are determined by the supporting activities of fuel suppliers and other responders.  In some rural areas, the First Responders also must perform CO source investigations and test individual appliances within the building.  If you have source investigation support by qualified technicians, your paperwork and possible victim placements are all that are required.

There are many scenarios for each situation.  If windows or doors were left open, the house may have ventilated before you arrived.  Your interior measurements may indicate little or no CO.  It is always recommended that appliances be tested before you allow the occupants back into the building.

Breath analysis may confirm the presence of CO but measurements inside may indicate no CO.  Complete testing of the building must be performed.  This will take time.  The housing of the inhabitants is then of concern.  The decision then is how and when and by whom is the next set of tests to be performed and who pays for it.

We may find that leaving a Bacharach Bodyguardâ4 with CO data-log capabilities in the building for several days will give us additional information about times of day when CO is highest in the building under normal operating conditions.  Noting the higher concentrations, when they occurred and finding out what systems were running, what weather conditions existed, how many people were home and other information can enlighten the source investigation team. 

If we don’t measure, we don’t know.