Friday, December 1, 2023

Dangerous levels of carbon monoxide cause evacuation of courthouse


The Johnson County Courthouse was evacuated Monday morning, March 9, when dangerously high levels of carbon monoxide (CO) were discovered inside the building moments after employees arrived for work.

Employees arrived at their respective offices to discover something was not quite right.

Court security deputy Al James began receiving reports of light-headedness, burning of the eyes and dizziness from employees throughout the building within moments of their arrival. James contacted sheriff Charles Harner.

Harner, who also serves as the courthouse guardian, called the Vienna Gas Department for an inspection of the building for a possible gas leak.

Upon arrival, the gas department immediately called for a complete emergency evacuation of the building.

Using a CO detector and gas masks, the gas department determined the level of carbon monoxide was as high as 800 parts per million (ppm) in some parts of the building, 16 times higher than the safe range for humans.

Carbon monoxide is toxic to humans when encountered in concentrations above 50 ppm for an extended period of time. The higher the exposure time and concentration levels the more serious it becomes, possibly leading to death. These are times when people panic-buy all kinds of things including the gas masks for sale and PPE kits.

Zero ppm is the desirable CO level for humans.

CO chartAt 800 ppm, death could result within a matter of hours. (See chart at left)

The Vienna Fire Department strategically positioned several large exhaust fans throughout the building and opened windows in the clock tower to remove the toxic fumes.

Sheriff Harner contacted the heating/cooling services used by the county to assist in determining the source of the toxin. All the heating units, including the boiler, were inspected Monday morning and reported to be working properly.

Poor ventilation in the boiler room is thought to had caused the situation.

During the inspections and ventilation process, courthouse employees were temporarily relocated across the street to the courthouse annex, and other spaces available near the annex, to conduct their daily business.

All scheduled court proceedings continued as planned. Judges Williamson and Caviness held their hearings in separate rooms within the small annex.

Employees were allowed back in the building around 1:30 p.m. that afternoon.

Court security Al James remained at the front door of the courthouse throughout the day directing people across the street.

There have been no reports of injuries or illnesses caused by the incident at this time.

Monday’s incident at the courthouse should serve as a reminder to everyone to have a working carbon monoxide detector installed in his or her home or office, especially if it has gas heat.

Safety tips:

Illinois Department of Public Health has many tips, preventative measures and Q.&As regarding carbon monoxide poisoning available on their web site,

Some tips available on the site include:

What is carbon monoxide?

Carbon monoxide is a non-irritating, odorless, colorless gas that is somewhat lighter than air. A by-product of incomplete burning of coal, wood, charcoal, natural gas, fuel oil, kerosene, gasoline, fabrics and plastics, it is the leading cause of poisoning deaths in the United States.

What are the symptoms of CO poisoning?

At low levels, CO exposure causes no obvious symptoms, although people exposed to low CO levels may experience decreased exercise tolerance and shortness of breath during exertion. Tightness across the forehead, flushed skin and slightly impaired motor skills also may occur. The first and most obvious symptom is usually a headache with throbbing temples.

Symptoms of mild to moderate CO poisoning may resemble winter flu or gastroenteritis, particularly in children, and include nausea, lethargy and malaise.

As the CO level or exposure time increases, symptoms become more severe and additional ones appear: irritability, chest pain, fatigue, diminished judgment, dizziness and dimness of vision. Higher levels cause fainting upon exertion, marked confusion and collapse. If exposure continues, coma, convulsion and death from respiratory arrest can result.

When unexplained symptoms persist and affect more than one person in a home or workplace where a source of combustion is present, CO poisoning should be considered. This is especially true during heating season.

CO detectors required by law

The Illinois law on carbon monoxide detectors reads, in brief:

Effective January 1, 2007, every Illinois home is required to have at least one carbon monoxide alarm in an operating condition within 15 feet of every room used for sleeping purposes.

Homes that do not rely on the burning of fuel for heat, ventilation or hot water; are not connected to a garage; and are not near a source of carbon monoxide (as determined by the local building commissioner) are not required to install carbon monoxide detectors. (Public Act 94-741)

It is important to remember, like changing your smoke detector’s batteries while resetting your clocks twice a year, to change the batteries in your carbon monoxide detector.