Featured Research

from universities, journals, and other organizations

New Carbon Monoxide Sensor Developed For Occupational Use

May 20, 1999
Lawrence Berkeley National Laboratory
A new lightweight, inexpensive, accurate carbon monoxide (CO) sensor and monitoring system has been developed by scientists at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and Quantum Group Incorporated (QGI, San Diego).

A new lightweight, inexpensive, accurate carbon monoxide (CO) sensor and monitoring system has been developed by scientists at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and Quantum Group Incorporated (QGI, San Diego).

Related Articles

Field testing of the new device at the Moscone Convention Center in San Francisco has shown that it is more accurate than the personal CO monitors currently available on the market.

"About 19,000 accidental carbon monoxide poisonings were reported by the American Association of Poison Control Centers in 1995," said Michael Apte, a scientist in Berkeley Lab's Environmental Energy Technologies Division, 'but very little is known about the actual extent and distribution of carbon monoxide exposures in the United States. Five hundred to a thousand accidental deaths a year are attributed to carbon monoxide poisoning, and it's the number one cause of unintentional poisoning in the United States."

Total numbers of poisonings are also difficult to estimate, according to Apte, because the effects of sub-acute CO poisoning are easily misdiagnosed as flu-like symptoms such as headaches and dizziness.

There is limited understanding about carbon monoxide exposure risks, partly because there has been no affordable way to accurately measure CO in the field. Some of the current methods of measurement require expensive, heavy equipment or unwieldy air bag samplers. Others are relatively inexpensive and lightweight, but they are not accurate or sensitive enough to provide credible quantitative results for a large number of sites.

To fill this gap in technology, Berkeley Lab and QGI worked together to develop the new CO sensor, which can clip onto a person's clothing. It can be used as an occupational dosimeter, which measures a worker's time-weighted average exposure to CO over an eight-hour period, or as a residential passive sampler measuring time-weighted average exposure in a home or office over a one-week period.

Carbon monoxide poisonings are most often caused by exposure to excessive indoor levels of the gas. Faulty combustion appliances such as gas stoves or gas-burning water or space heaters can raise CO levels into the danger zone, as can automobile exhaust in enclosed spaces. "Although carbon monoxide concentrations are regulated outdoors by national and state ambient air quality standards, most people spend 90 percent or more of their time indoors, which is where elevated CO exposures are likely to occur," said Apte.

The LBNL/QGI Occupational CO Dosimeter (LOCD) consists of a square polystyrene vial less than two inches long. The device contains a carbon monoxide sensor made of palladium and molybdenum, a diffusion tube to control the rate at which CO is sampled, and a cap to seal the system.

"When the user removes the cap, air flows into the diffusion tube at a constant rate over the sampling period, typically an 8-hour work shift," Apte explained. "CO in the air reacts with the sensor at the end of the tube, turning it from yellow to blue in proportion to CO exposure. Analysis is simple-the device is placed into a standard lab spectrophotometer which, by measuring its color change, instantly indicates how much carbon monoxide the sensor absorbed. A single LOCD can be reused many times."

To prove that the sensor works accurately in the field, Apte and his Berkeley Lab team conducted a study of the CO exposure of workers at San Francisco's Moscone Convention Center in cooperation with Crawford Risk Control Services, an Oakland (CA) firm.

During the set-up of shows in the Center's 442,000 square feet of exhibition spaces, some 40 propane-powered forklifts are active almost continuously throughout the building. Diesel trucks also drive up to interior docks from the outside.

Before the study, Moscone Center management had already put a number of safety measures in place to reduce worker and building occupant exposures to CO, including installing catalytic converters on the forklifts and modifying the building's ventilation system to reduce exhaust concentrations.

The Berkeley Lab team provided 60 workers who volunteered for the study with the new occupational sensor, which was clipped to the workers' lapels. They were also given commercially available diffusion tubes, a current method used for measuring CO exposure. The Berkeley Lab team also measured CO levels using traditional methods, including air bag samples analyzed in an EPA-approved lab procedure, and real-time CO personal monitors containing an electrochemical sensor. Exposures were measured over a three-day period.

The tests showed that the LOCD measured average workshift CO exposures accurately to within one part per million. The commercially available diffusion tube under-reported CO exposures by an average of about 3 parts per million.

"The results show that the new device represents a major improvement over current measurement technology," said Apte.

Worker CO exposures were almost all below the strict Cal-OSHA occupational standard of 25 parts per million. One worker who exceeded the standard probably received excessive exposure from operating a forklift in an enclosed semi-truck trailer, Apte said.

QGI is now looking for private-sector partners for distribution and is developing plans to manufacture and market the CO occupational dosimeter. A paper summarizing this research, "A New Carbon Monoxide Occupational Dosimeter: Results from a Worker Exposure Assessment Survey," will be published in the Journal of Exposure Analysis and Environmental Epidemiology. Its authors are Apte, Katherine Hammond, Lara Gundel and Daniel Cox.

Berkeley Lab scientists developed the diffusion tube technology used in the LOCD; the CO sensor technology was developed by QGI and validated by Berkeley Lab. The Department of Energy funded the project under an Office of Science-sponsored Cooperative Research and Development Agreement (CRADA). An early phase of the research was funded by the Office of Building Technologies, State and Community Programs.

DOE's Laboratory Technology Research (LTR) program, which sponsored the LOCD work, supports high-risk multidisciplinary research partnerships to investigate challenging scientific problems of interest to DOE and industry. In a recent LTR Industry Partner Survey involving over 100 companies, 91 percent of the companies said they had benefited from partnering with the laboratories and 97 percent of the companies said they would like to partner again with one of the labs on a future research project.


Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified research and is managed by the University of California.

Story Source:

The above story is based on materials provided by Lawrence Berkeley National Laboratory. Note: Materials may be edited for content and length.

Cite This Page:

Lawrence Berkeley National Laboratory. "New Carbon Monoxide Sensor Developed For Occupational Use." ScienceDaily. ScienceDaily, 20 May 1999. <www.sciencedaily.com/releases/1999/05/990520071752.htm>.
Lawrence Berkeley National Laboratory. (1999, May 20). New Carbon Monoxide Sensor Developed For Occupational Use. ScienceDaily. Retrieved March 1, 2015 from www.sciencedaily.com/releases/1999/05/990520071752.htm
Lawrence Berkeley National Laboratory. "New Carbon Monoxide Sensor Developed For Occupational Use." ScienceDaily. www.sciencedaily.com/releases/1999/05/990520071752.htm (accessed March 1, 2015).

Share This

More From ScienceDaily

More Matter & Energy News

Sunday, March 1, 2015

Featured Research

from universities, journals, and other organizations

Featured Videos

from AP, Reuters, AFP, and other news services

Rehab Robot Helps Restore Damaged Muscles and Nerves

Rehab Robot Helps Restore Damaged Muscles and Nerves

Reuters - Innovations Video Online (Mar. 1, 2015) A rehabilitation robot prototype to help restore deteriorated nerves and muscles using electromyography and computer games. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Elon Musk's Hyperloop Moves Forward

Elon Musk's Hyperloop Moves Forward

Buzz60 (Feb. 27, 2015) Zipping around at 800-miles an hour is coming closer to reality in California. An entire town is being built around Elon Musk&apos;s Hyperloop concept and it wants you to stop in for a ride when it&apos;s ready. Brett Larson is on board. Video provided by Buzz60
Powered by NewsLook.com
Vibrating Bicycle Senses Traffic

Vibrating Bicycle Senses Traffic

Reuters - Innovations Video Online (Feb. 26, 2015) Dutch scientists have developed a smart bicycle that uses sensors, wireless technology and video to warn riders of traffic dangers. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
In Japan, Robot Dogs Are for Life -- And Death

In Japan, Robot Dogs Are for Life -- And Death

AFP (Feb. 25, 2015) Robot dogs are the perfect pet for some in Japan who go to repairmen-turned-vets when their pooch breaks down - while a full Buddhist funeral ceremony awaits those who don&apos;t make it. Duration: 02:40 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.


Breaking News:

Strange & Offbeat Stories

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News


Free Subscriptions

Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile

Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?

Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins