As plumbing and heating professionals become increasingly aware of the dangers of CO while on the job, new products make it easier to raise alarms in dangerous environments.

Carbon monoxide and other gas monitors now can be worn or carried by technicians in lightweight and compact devices - small enough for a shirt pocket, or worn on a tool belt.

Jim Davis, veteran CO tester, teacher and combustion mentor for National Comfort Institute, advocates wearing such devices, and always carries his CO stick monitor when he evaluates buildings and mechanical rooms. The model 317-3 CO stick from Testo Inc. detects the presence of CO and warns the wearer both visually and audibly. It doesn't require any zeroing - just turn it on - and it features a self-test mode to verify the CO sensor without the need for test gas.

“You can find CO everywhere,” he warns. Even at the hotdog stand for a quick bite to eat.

Davis travels the country, speaking at conferences and training entire companies about CO. He's given testimony during legal snafus where a contractor is held liable for servicing a piece of heating equipment that later was found to emit lethal levels of CO, killing members of a household.

Many of Davis's biggest supporters were once clueless plumbing and heating contractors looking for more information about CO, fearful that their customers and families could be in danger. Or worse, that they, too, might be next in a litigation battle if a death or injury occurs.

Wearing portable CO monitors can warn you in real time if you're being exposed to elevated or life-threatening amounts of CO. This could possibly save a technician's life if he enters a home or building to perform repairs to damaged equipment that is unknowingly emitting high amounts of the poison gas.

John Ruhnke of JR's Plumbing & Heating (Norwalk, Conn.) knows firsthand how a serious situation can be averted by using portable monitors.

After a recent service call, one of JR's technicians called in sick the following day. But a part was still needed to complete the repair. Stand-in tech Fred went to complete the call when his battery-operated CO monitor alarmed him. He wasn't there to service the home's boiler, but when a combustion analysis was performed with a Bacharach Fyrite Pro, the boiler was found to give off very high levels of CO to the chimney - the fuel mixture was too rich. The gas valve was adjusted to correct the problem.

Upstairs in the residence lived a 40-year-old woman. CO levels were found at near 50 ppm. She was notified of the danger and strongly encouraged to purchase a CO monitor for her home.

Tools To Use

Portable monitors read very low levels of gas after only a few seconds' exposure to raised levels. Unfortunately, some home monitors only go off after 70 parts per million, and can take up to four hours to go off; too long to be exposed to CO.

Ruhnke feels that portable monitors raise the bar in the industry, as well as awareness in his customers. He's also passing on to his technicians the tradition of caring for the safety of their clientele and the well-being of the company's employees.

Ben Graf with Aim Safety of Aerion Technologies (aerion is Greek for “gas”) says testing for CO is very important to anyone who deals with combustible gasses. Wearing pocket monitors is a step toward awareness and ultimately is used to save lives. “The monitors protect the worker from dangerous environments, as well as protect the customers,” Graf says.

Aim offers several models of portable monitors with varying function and price. The single-gas detection models - like the popular 450 series - are ideal for plumbing and heating professionals because of their lightweight and visible display (upside-down for adequate viewing when clipped on).

Advanced features for equipment such as the Alien single-gas model offer datalogging and software for analysis. (This series is sometimes used by law enforcement to test suspected meth labs.)

The new Pilot model is a multigas detector. Graf notes there are the “standard four” gasses that require monitoring: carbon monoxide, oxygen, combustibles (methane) and hydrogen sulfide (sewer gasses). The Pilot is inexpensive (comparable to the 450) and offers some datalogging, but it is lighter weight and can be worn on a belt.

All of Aim's portable monitors feature a two-year warranty, and are designed ruggedly. They were built for use in small confined spaces. Aim's products are available through safety equipment distributors.

Some of the contractors Davis hasn't trained through NCI often use the excuse, “Well, we haven't killed anyone yet.” But he would like to know who's going to volunteer to be the first? Davis likens the awareness of CO dangers to driving drunk. The culture has changed in the past decades regarding the dangers of driving under the influence and also about wearing seatbelts, or pulling over to talk on the phone. He feels the time will come for mandated CO detection.

Until then, real-time testing for CO can be performed by your company easily through carrying a simple but effective detection device in your pocket.

For further information on NCI, visit To contact Aim Safety, visit the Web site Information on Testo Inc. can be viewed at

CO can cause neurological, heart and respiratory damage and disease. It can stay in the blood for hours and not show noticeable symptoms.

Carbon Monoxide Levels Chart
9 ppm - maximum level vented appliances may emit.
25 ppm - maximum level allowed in parking garages.
30 ppm - first level that can contribute to congestive heart failure. Dangerous for infants, elderly, infirm.
70 ppm - level that UL-listed alarms must sound within four hours.
200 ppm - possibly fatal to infants, elderly, infirm.