Machine Design

Warnings Are Not Enough to Ensure User Safety from Generator Fires, Shocks, and Carbon Monoxide

Underwriters Laboratories recently published UL 2201, a Standard for Portable Engine-Generator Assemblies. UL Director of Standards Don Snyder explained the rationale behind the standard.

He pointed out that almost 370 generator-related deaths occurred between 1990 and 2005, many of them after a hurricane or major storm. He also said most of the reported incidents involved carbon-monoxide (CO) poisoning, which is why UL thinks it is critical for manufacturers to place prominent warning labels advising consumers where they can safely use portable generators.

Most of the warnings are common sense. For example, Snyder says, “Never use a generator indoors, in an attached garage, or where it can be exposed to rain or snow. Always read the instructions. And never plug an electric portable generator into a regular household outlet. Use a heavy, outdoor- rated cord for the generator, and have an electrician hook the standby electrical system to household wiring, if needed.”

Finally, warning labels or markings must give consumers critical safe-usage instructions, including a heads-up about the risk of CO poisoning.

Warning labels are admirable, but in the case of CO, you have to ask whether warnings are enough. The Consumer Product Safety Commission has identified CO poisoning, electrical shock, and fire as the three major safety issues associated with portable generators. But the new UL standard does not address them in any way other than with warnings posted on the products.

The technology presently exists for systems that will sense hazardous levels of CO. A system that shuts down the generator and sounds an alarm when the CO level reaches a predetermined limit would not be difficult or costly to implement.

I have investigated many serious incidents of CO poisoning associated with portable generators. In every case, the victim had taken action he thought would meet the instructions and warnings regarding proper ventilation. And in every case, he had guessed wrong. A safe design would have protected them.

People used to be electrocuted when they used hair dryers in bathrooms, but I have not heard of a single electrical-related death involving hair dryers with built-in ground-fault-circuit interrupters. Hair-dryer manufacturers addressed this hazard, so why couldn’t portable-generator manufacturers? Again, this would not be a difficult or costly modification.

Every portable-generator-related fire I have investigated was the result of someone spilling gasoline while filling the gas tank. A label can warn the operator of this danger, but with some help from designers hazardous spills could be made less likely.

Instead of papering over deadly problems with warning labels, the UL standard should require that hazards (1) be designed out, (2) be guarded against, and as a last resort, (3) be warned about. It is my opinion that this standard does not go far enough.

Lanny Berke is a registered professional engineer and Certified Safety Professional involved in forensic engineering since 1972. Got a question about safety? You can reach Lanny at [email protected].

Edited by Jessica Shapiro

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