Home Use Generators: Dangerous and Behind the Curve

In late October 2011, Connecticut was hit by a rare early-season snowstorm that left more than 860,000 businesses and homes in that state without power. And some state residents who didn’t or couldn’t wait for the power to be restored, tried to survive the outage with the use of a portable generator. From the day of the storm until November 9, the Department of Public Health received 143 reports of carbon monoxide poisoning – nearly nine times the number of reports – 16 – for the previous three years combined. Five individuals died and 41 required a hospitalization; the majority of incidents were caused by portable generators for home use.

In writing about this surge in the Connecticut Epidemiologist, the researchers noted: “Outbreaks of CO poisonings following winter storms are well documented and continue to be a problem.”

Carbon monoxide (CO) is a potentially deadly gas found as a byproduct of internal combustion engines that is odorless, colorless and tasteless. According to the latest figures from the CPSC, from 1999 to 2011, 695 – nearly 80 percent – of the 881 fatalities from 513 incidents were associated with generators. And CO poisonings from home generators will continue to be a problem, because the only countermeasure mandated by the U.S. Consumer Product Safety Commission are warnings. While other engine-manufacturing industries, such as automotive and marine generators, use available technology to significantly reduce their CO emissions, makers of portable generators for home have been relying on capital letters and pictograms to avert injury and death.

The data suggest that dramatically worded warning labels don't do enough to depress the injury and mortality rate. According to CPSC spokesman Scott Wolfson, there was a noticeable decline in CO incidents involving generators after the recent Mid-Atlantic derecho and Hurricane Issac. Nonetheless, the CPSC has been exploring technical solutions to the CO hazard since 2006.

The CPSC first became involved in the issue in 2002, when the generator-involved CO fatalities began increasing annually. The agency began to track the incidence of poisoning and deaths and commented on the drafting of voluntary standard that was initiated by Underwriters Laboratories in 2003. (In 2009, UL published voluntary standard 2201. According to a UL news release, the only aspect of the standard that addressed the CO hazard was a requirement for “clear usage labels that may help reduce the known risks of CO poisoning and electrocution.”)

But it was one of the most active and deadly hurricane seasons in recent memory that motivated the CPSC to take some action. Category 5 Hurricane Katrina, with the submerging of New Orleans, $81.2 billion in damage and a death toll of at least 1,836, remains an iconic catastrophe. Yet, that year, seven major hurricanes made landfall, most of them in the U.S. The successive waves of weather-related devastation caused the CPSC, which previously issued a consumer warning about portable generators and CO hazards about once annually, to publish an unprecedented five over a three-month period.

By October, then-CPSC Commission Chairman Hal Stratton ordered his staff to undergo a complete review of portable generator safety, including a feasibility study of safety cut-offs, performance requirements to substantially reduce CO emissions, weatherization for safety in wet and cold environments, better public awareness campaigns, the creation of a private sector group to develop a technical solution, and stronger warning labels.

According to the October 2006 briefing package that the CPSC assembled for the commission, “the feasibility of performance requirements to substantially reduce consumer exposure to CO should be pursued. Examples include reducing the generator engine's CO emission rate or through use of sensors that can detect hazardous ambient CO levels and shut off the generator in time to prevent serious injury or death.”  The Commission never got farther than a rulemaking to up the wattage of the warning labels.

In January 2007, CPSC passed a Final Rule requiring the warning label to add pictograms and to state: “Using a generator indoors CAN KILL YOU IN MINUTES; ‘‘Generator exhaust contains carbon monoxide. This is a poison you cannot see or smell; NEVER use inside a home or garage, EVEN IF doors and windows are open; Only use OUTSIDE and far away from windows, doors, and vents.’’ The law did not require the warning language to include a Spanish language version on the theory that Hispanics only represented a 5.6 percent slice of portable generator purchasers in 2005, and some of them were probably illiterate in their native language, so a warning label wouldn’t help them anyway.

“Despite these findings, the Commission does not dismiss the potential usefulness of providing the information in the labeling in Spanish, especially in regions of the country with large Hispanic populations. Thus, the rule does not prohibit manufacturers from providing a Spanish-language version of the labeling in addition to the prescribed English-language label,” the rulemaking said.

The new warning language requirement was effective in May 2007. In the five years since, the agency has not tried to measure the efficacy of heightened warnings. However, the portable generator death and injury data seem to correlate more closely with weather — specifically, weather disasters. Besides the Connecticut snowstorm example, 2005, with its series of strong hurricanes, was a national high point for generator-involved CO deaths – 64 reported deaths compared to 49 in 2004.  A surveillance study of CO poisonings in Florida compiled by the state health department noted that most of its cases were related to cold weather, however: “Past studies show that generator related CO poisoning were increased after hurricane landfalls in Florida. The number of generator related CO poisoning cases (n=15) were lower in 2010. There was no hurricane landfall in Florida during this year.”

In fact, despite warning language to NEVER use a generator in a home or garage, more consumers are doing so after the labeling requirements went into effect than before the capital letters and pictograms were mandated. According to the CPSC’s 2012 incidence report:

“In recent years, the most common location of generators associated with CO fatalities has shifted from the basement to the non-basement living space of the home. From 2004 through 2011, 38 percent (169 of 442) of CO fatalities in the home occurred with a generator placed in the non-basement living space of the home, compared to only 21 percent (23 of 109) of non-basement use of generators from 1999 through 2003.”

For this reason, perhaps, the CPSC staff has not given up on the technological approach that it first advocated six years ago.

Certainly the CPSC has a model in the automotive and marine engine industries. In 1975, the automobile industry began to equip their products with catalytic converters to meet the emission limits required by the Clean Air Act of 1970. According to the National Institutes of Occupational Health this development was “a lifesaver,” as demonstrated by an analysis of unintentional vehicle-related CO deaths from 1975 to 1996, showing an 80 percent decline.

In 2005, market demand compelled the marine industry to adopt the voluntary, but stringent CO emission standard for the small, water-cooled spark-ignited engines used to power marine generators. Three manufacturers developed low-CO products: Westerbeke and Kohler, which used electronic fuel injection to control CO emissions, and Indmar, which developed an engine using a catalytic control device. In 2008, the U.S. Environmental Protection Agency adopted the voluntary CO emissions level as a mandatory standard.

This year, the CPSC published a report on its low-CO emitting generator technology demonstration project. Its purpose was: to see if an engine with a substantially reduced CO emission rate could be developed that would reduce the risk of fatal and severe CO poisoning when used in an indoor location. The report described the strategy as an effort not to reduce the CO emissions rate to make portable generators safe for indoor use, rather, to reduce it enough to delay the onset of CO poisoning symptoms and slow their worsening, so that occupants have time to recognize their exposure and exit the building.

“The high CO emission rate of current generators can result in situations where the exposed person experiences extremely quick onset of confusion, loss of muscular coordination, loss of consciousness, and death with little or no time in experiencing the milder CO poisoning symptoms. Without adequate warning provided by milder symptoms, victims have very little, if any, time to recognize that an imminent life-threatening environmental hazard is occurring and to seek safety or take other actions that could help their situation after the initiation of the exposure.”

The CPSC built a prototype, in which closed-loop electronic fuel injection with stoichiometric fuel control and a three-way catalyst were adapted onto the engine of a commercially available portable generator. CO emissions were reduced by 95 percent. In a second demonstration, researchers tested a similar generator in its OEM configuration and prototype configuration, in common fatal scenarios of a generator operating in the attached garage of a single-family home. In addition, the researchers performed health effects modeling to estimate the time in which occupants would become aware of their CO exposure.

In the demonstration project report, CPSC researchers concluded: “Based on the data patterns in the CPSC’s incident data, staff believes that many future fatal and serious CO poisonings involving consumer use of generators can be prevented if industry were to adopt a stringent CO emission standard for engines installed in generators on the order of that achieved with operation of the CPSC prototype.”

Will industry go first? Or will the CPSC initiate a rulemaking? The earth is warming – and increasing the odds of dramatic weather events. At the same time, the nation’s electric power gird is aging and stretched thin. This is the perfect storm for more outages, more home use of portable generators, and more CO poisoning when the winds come up and the power lines go down.


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