Nov 14, 2005 9:50 pm US/Central

Deadly Silence: CO Detectors Fail To Warn Of Gas

Ed Curran
Reporting

(CBS) NAPERVILLE More than 10 years ago a Chicago ordinance required homes to have a carbon monoxide detector to warn you if the deadly gas is present.

But even if you change your battery every year and press the test button regularly, you may not be protected.

Your detector may not be working properly or not at all. CBS 2's Ed Curran reports on what could be a deadly silence.

“It was kind of scary, you pass out in the bathroom and wake up on the couch and you have no idea,” said Vigunya Voratanitkitkul.

In March, Voratanitkitkul’s boyfriend, Logan, found her lifeless body on the bathroom floor.

The Chicago Fire Department found high levels of carbon monoxide in their home -- 206 parts per million. She did not have a CO detector.

“They said we were lucky to be alive,” Voratanitkitkul said.
Naperville Assistant Fire Chief Rich Mikel has pulled many people out of homes filled with carbon monoxide.

Carbon monoxide is a silent killer. You cannot see, taste or smell it. At high enough levels, you could be dead within an hour.

Your detector is your last and perhaps only defense in an emergency. So how do you know if it's working?

“I wouldn't trust a CO detector more than 2 years old. I'd toss it and get a new one. Unfortunately, I can’t guarantee the new one's going to work,” said gas detection expert Paul Clifford.

Clifford has extensively studied home carbon monoxide detectors. One of his studies show that commercial brands behave inconsistently, with four out of five failing at low humidity levels, similar to Chicago winters.

We recruited 13 Chicago area families for a test. With the help of the Naperville Fire Department, we burned carbon monoxide rich charcoal to see if their detectors, plus one we purchased new, worked.

When the fire department measured carbon monoxide levels topping 100 ppm, the digital read outs of the CO detectors read 63, 48, 44, 41, 135, 19, and 0.

The digital readings are all over the map and they can be. Right now they don't have to be accurate. In 2007, Underwriters Labs will require them to have a margin of error of plus or minus 30 percent.

“Many sensors being used are inaccurate,” Clifford said. “It's only going to go off once, you may already have a deadly level of CO poisoning, and that's not good enough.”

Back to our test -- the poisonous gas continues to mount and one detector still has not gone off.

Our meters show us 475 ppm in this room. Every detector's gone off except one. It shows less than 60 ppm.

That malfunctioning CO detector belongs to Bill Michiels. For seven years, his family used it in their Oak Park home.

“There's nothing on this to indicate there's an error to me,” Michiels said.

It turns out Michiel's detector had been recalled six years ago. His is among more than one million recalled by the Consumer Product Safety Commission over the last 10 years.

When you press the test button on most CO detectors, you're testing the electrical circuits, not the gas sensor. A warning or signal to tell you the sensor's no longer working is not required by Underwriters Lab.

The CPSC wants that changed. In one report it says "UL should include an ‘end of life’ signal."

Underwriters Lab say they're working on it.

“That's a possible recommendation for the standards development committee. Any reasonable recommendation is accepted and will be evaluated thoroughly,” said John Drengenberg with Underwriters Laboratories.

Underwriters Laboratories says standards for detector performance in low humidity levels will be strengthened in 2007.

Most of the detectors we tested were older and technology has advanced a lot.

Underwriters and all the companies we spoke with, including First Alert, Kidde and American Sensors, all recommend replacing carbon monoxide detectors every five years.

Both Kidde and American Sensors are manufacturing newer models that have an "end of life" signal.

The bottom line here is detectors do save lives -- just replace them more often.

(© MMV, CBS Broadcasting, Inc. All Rights Reserved.)

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