The following letter is the Response of Albert Donnay, President of MCS Referral & Resources, Inc. to an Inquiry from Karyn Scurti, of Proctor Engineering, in behalf of the ASHRAE C O Committee considering CO Alarms made to the UL-2034 Standard, at the ASHRAE Meeting in Chicago, in Jan., 2003.

Karyn Scurti wrote to Albert Donnay:

Dear Sir,

Your name was given to us by TSI International.  We are very interested in learning more about the reliability of CO detectors for an upcoming  ASHRAE meeting where they will review the possibility of a new Standard for residential homes.  If you have any information to provide in favor or their reliability, it would be greatly appreciated.  The information below is an e-mail from our President, John Proctor, P.E. who put the call out for this information.  ASHRAE will be meeting next week.

Thank you.

Karyn Scurti

Executive Assistant
(415) 451-2481

From: John Proctor, P.E.
President of Proctor Engineering Group, Ltd.
Voting Member of ASHRAE 92.2P Committee

Urgent Request to All CO Detector Manufacturers:

We need additional information on the reliability and advisability of CO Detectors. We are particularly interested in how the current UL Standard was developed and changed as well as the Canadian Standard. We are interested in why low level detection is treated by the UP Standard in the way it is.

We are interested in any and all information you have available or can get your hands on concerning the reliability of CO Detectors.

I presume that you have copies of the various studies sponsored by the gas industry and that you may have contrary opinions and information. If you do not have copies of their studies I would be happy to send them to you.

Please respond as soon as possible. If you are interested in attending and addressing the ASHRAE meeting, I believe that can be arranged.

Sincerely
John Proctor, P.E.

Albert Donnay's response:

Subject: Re: Carbon Monoxide Detectors to be Discussed at ASHRAE Meeting

Thanks for consulting me.  Do you have the latest GRI study of home CO detectors ?  It shows there is still much variation in home CO alarm accuracy (ranging from single digit to triple digit!).  Also, now that AIM units are no longer in production, there are no home CO alarms on the market that either automatically or manually can test their CO sensor to see if it still works.  (the AIM units had an internal
hydrolyzer that tested the CO sensor's  response to hydrogen as a surrogate for CO).

Pushing the "test" button in all other units only tests the electronics, not the sensor, so users have no idea if/when the sensor  drifts far out of range or fails to detect CO completely.

Given that people may die under such circumstances, I consider this an unacceptable flaw. Smoke testing of home CO alarms (with manuf. supplied CO or by consumer with a cigarette) also may not work since an atmosphere of at least 400ppm CO must be maintained  for at least 5 minutes in order to reach the fastest UL2034 alarm threshold.

Worst of all is that all the UL 2034 standard time/exposure alarm thresholds are based on the assumption that people only need to be warned if/when their COHb level exceeds 10%.  But as I recently documented in a letter to Environmental Health Perspectives (the journal of US NIEHS), the often published table that shows the CO symptoms expected at various COHb levels (and no symptoms below 10%) is not based on ANY actual data!!! (click here to read letter ).

While some CO alarms now display a "COHb" level, this is never accurate and misleading even it were, since the medical literature makes clear that COHb levels do not correlate with the signs, symptoms or severity of CO poisoning.

In fact, asthmatics react badly to just 2-3 ppm of CO exposure, and low birth weight babies are associated with 3rd trimester exposures averaging as low as 6ppm.

While some CO alarms may save some lives (if they are still working), they too often give only a false sense of security as they fail to
warn people of low levels and transient spikes.   As I've petitioned it to do, the ASHRAE 62.2 committee could do much more to protect public health by restoring the requirement it dropped from the 1989 edition (apparently inadvertently, at least it gave no reason for doing so deliberately) that attached residential garages be built with 100cfm of continuous exhaust ventilation per vehicle, as section 403.3 of the Intl Mech Code still requires.

Such fans would entirely eliminate the buildup of CO indoors from  largest unvented CO source in most modern homes.

Albert Donnay, MHS
Donnay Environmental Health Engineering

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