Lee Doran and Regina Romary
National Board consultant and National Board publications editor,
Summary: The following article is a part of National Board
Classic Series and it was published in the National Board BULLETIN. (3 printed pages)
A silent killer finds its way into the headlines each winter. This year was no
different, with frequent reports of the deaths and illnesses caused by carbon
monoxide poisoning, usually in permanent residences. Yet carbon monoxide
emission, which causes no damage to the boiler equipment whatsoever, is almost
When it comes to boiler accidents, most people relate to a boiler explosion or
a combustion chamber explosion. Yet incidents involving carbon monoxide are
much more frequent than the other two combined.
According to the U.S. Consumer Product Safety Commission, an estimated 250
persons die and almost 5,000 are injured [an October 2000 press release cites
more than 10,000] each year in non-fire-related carbon monoxide poisoning.
Estimates of nonfatal injuries are difficult to determine because many victims
do not seek treatment or are misdiagnosed as having colds or influenza.
However, these estimates suggest that there are 20 nonfatal injuries for every
fatal carbon monoxide poisoning.
Accident investigation results consistently attribute blame to the venting
systems. Recent articles have warned of venting failures which might allow
carbon monoxide to leak into buildings. But the vent pipe is actually only part
of the problem.
Further investigation would reveal that it is the burner that isn't operating
properly. When the burner is not receiving enough air, unburned fuel is
released in the forms of carbon monoxide and soot. The root cause of any carbon
monoxide emission is the burner operating without enough air.
So why is the venting so often blamed? Investigators will usually end their
search at a faulty flue pipe, not realizing that there would be no problem if
poisonous gas wasn't being produced by the burner. In most jurisdictions,
carbon monoxide failure investigations are conducted by the fire marshal's
office. Unfortunately, personnel in fire prevention are unlikely to be
thoroughly trained in investigation of boilers and water heaters. It is
improbable that unqualified personnel will identify problems and potential
problems that might exist.
Most jurisdictions have firm lines separating the responsibilities of their
departments; in particular, the responsibilities of the fire prevention and
boiler safety branches are well-defined. By this division of duty, boiler
safety personnel are usually charged with the inspection of a boiler or
pressure vessel's steam or waterside operation, while fire prevention personnel
are responsible for the portion of the equipment involving fire. Likewise,
insurance companies commonly assign investigation responsibilities the same way
between fire and property insurance personnel.
The problem with this arrangement is that, as mentioned, fire prevention
personnel often aren't trained to inspect or investigate boilers and pressure
vessels. In fact, it isn't always clear that inspection of the equipment falls
within their domain. Frequently the end-result is that no one inspects the
fuel-firing apparatus. Problems with the burner, such as improper calibration
or worn-out parts, go undiscovered until it's too late.
It is extremely important that the entire boiler be inspected, including all
connecting apparatus and auxiliary equipment. Inspection of the entire boiler
as a complete system is the only way to ensure safe operation.
For this reason, many jurisdictions of the U.S. and Canada have adopted ASME
CSD-1: Controls and Safety Devices for Automatically Fired Boilers. CSD-1
addresses combustion equipment requirements as well as steam and waterside
control, testing, and operation in the inspection and investigation of boilers.
Twenty-eight states and jurisdictions of the U.S. and Canada require at least
part of CSD-1.
Florida is one state that has adopted only the portion of CSD-1 concerning
steam and waterside controls of boilers. This standard was in effect on
February 2, 1995, when a guest in a Tampa hotel died, apparently from carbon
monoxide poisoning. The matter is still under investigation. Another person
died two years ago when carbon monoxide leaked into a West Palm Beach hotel.
Investigation in that case revealed a malfunctioning boiler burner system,
according to Billy Smith, assistant director of the Florida State Fire
Marshal's Office. Full compliance with CSD-1 and complete boiler-system
inspection might have prevented such tragedies.
As the standard becomes more widely known and used, personnel in fire
prevention and boiler safety are recognizing the interdependence of a boiler's
pressure and fuel-firing apparatuses. Expanding use of CSD-1 is improving
safety of boilers and pressure vessels through better inspection, greatly
reducing risk to the public.
But prevention of carbon monoxide poisoning doesn't stop with the appropriate
inspection of boilers and pressure vessels. Proper care, testing, and
maintenance of the equipment is vital to its safe operation. Due to budgetary
constraints, public buildings such as schools and churches are often forced to
forgo training for their boiler maintenance personnel. Other times, management
simply does not recognize the need for training of operation and maintenance
personnel in this extremely vital area. The risk to the people who enter these
buildings every day greatly outweighs the nominal cost of training.
In its training efforts, the National Board has included instruction on boiler
fuel-firing apparatus and combustion-side controls in its Inservice Inspection
Seminar (ISI), presented in a jurisdiction by request of its chief inspector.
These portions of the seminar ensure the boiler inspector understands the
basics of the equipment and the importance of safe operation. In addition, the
seminar offers a jurisdiction's chief inspector the opportunity to invite
operators/maintainers/owners and service organizations, in an effort to improve
the safety of the general public within that jurisdiction. But this is a small
effort. More must be done in this area.
With trained personnel, proper maintenance, and inspection of the boiler or
pressure vessel as a complete unit, carbon monoxide poisoning will not continue
to be the deadly problem it is. Just as the venting system is the often-blamed
symptom of a larger problem, so is the carbon monoxide emission indicative of a
lack of the proper care a boiler requires.
Editor's note: Some ASME Boiler and Pressure Vessel Code requirements may have changed because of advances in material technology and/or actual experience. The reader is cautioned to refer to the latest edition and addenda of the ASME Boiler and Pressure Vessel Code for current requirements.