Study provides details on portable generator emissions and carbon monoxide exposure

July 11, 2013

Despite warnings to the contrary, many people continue to operate portable generators indoors or close to open windows, doors, or vents, resulting in more than 500 deaths since 2005. And each year, more than 20,000 people visit the emergency room and more than 4,000 are hospitalized due to exposure to toxic levels of carbon monoxide (CO), a colorless, odorless gas. Fatality is highest among people 65 and older.

A new computer modeling study by National Institute of Standards and Technology (NIST) researchers scrutinizes the deadly relationship between CO emissions and occupant exposure. They conducted simulations of 87 types of dwellings representative of the U.S. housing stock with a generator operating within a room in the house, its basement, or attached garage.

The study considered two scenarios of portable-generator operation: continuous operation for 18 hours and operation with some type of control technology that causes the generator to shut off periodically, or so-called "burst" releases.

Regardless of housing type or location, generators that release as little as 27 grams of CO per hour continuously for 18 hours cause 80 percent of the modeled cases to result in an exposure predicted to reach dangerous levels. In comparison, current commercially available generators that were tested by NIST in a previous study emitted CO at a rate of 500 to 4,000 grams per hour.

For generators characterized by burst releases of CO, the NIST team found that CO emissions of more than 139 grams resulted in dangerous levels of exposure.

The findings, reported to the U.S. Consumer Product Safety Commission, could help in setting limits on CO emissions from portable generators.

Explore further: Prototype generators emit much less carbon monoxide

More information: Persily, A. et al. Residential Carbon Monoxide Exposure due to Indoor Generator Operation: Effects of Source Location and Emission Rate (NIST Technical Note 1782), June 2013. Downloadable from:

Emmerich, S., Persily, A. and Wang, L. Modeling and Measuring the Effects of Portable Gasoline Powered Generator Exhaust on Indoor Carbon Monoxide Level (NIST Technical Note 1781), Feb 2013.

Related Stories

Prototype generators emit much less carbon monoxide

April 17, 2013

Portable electric generators retrofitted with off-the-shelf hardware by the University of Alabama (UA) emitted significantly lower levels of carbon monoxide (CO) exhaust, according to the results* of tests conducted by the ...

Pricing can cut CO2 emissions from electric generators

April 28, 2008

Levying a price on carbon dioxide released by electric generators could considerably reduce greenhouse gas emissions — even before the deployment of any environmentally friendly technology — according to scientists in ...

Recommended for you

Microsoft aims at Apple with high-end PCs, 3D software

October 26, 2016

Microsoft launched a new consumer offensive Wednesday, unveiling a high-end computer that challenges the Apple iMac along with an updated Windows operating system that showcases three-dimensional content and "mixed reality."

Making it easier to collaborate on code

October 26, 2016

Git is an open-source system with a polarizing reputation among programmers. It's a powerful tool to help developers track changes to code, but many view it as prohibitively difficult to use.

Dutch unveil giant vacuum to clean outside air

October 25, 2016

Dutch inventors Tuesday unveiled what they called the world's first giant outside air vacuum cleaner—a large purifying system intended to filter out toxic tiny particles from the atmosphere surrounding the machine.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.