Companies seeking Energy Star certification for their products must furnish lab test results to verify energy use before they can use the famous label.

The new requirement is the latest move by the U.S. Environmental Protection Agency and the Department of Energy to strengthen Energy Star. Despite broad recognition of the label, the brand's reputation has been tarnished in recent years because of reports that some labeled products failed to meet the program's standards.

In 2008, a Consumer Reports study found actual energy use of some labeled products exceeded the program's standards, such as an LG refrigerator with an average annual energy consumption of 1,110 kilowatt hours with its icemaker on -- well above its claimed consumption of 547 kWh.

The report also concluded that in some categories, nearly all products meet the energy-savings requirements of the program even though only a quarter of available models should meet the standards.

A recent report (PDF) from the Government Accountability Office described the weaknesses in the Energy Star's automated approval process, concluding the program was largely a self-certification system that is vulnerable to fraud and abuse.

The GAO received Energy Star certifications for 15 bogus products, including a generator-sized alarm clock powered by gasoline and an "air room cleaner" that resembled a space heater equipped with a feather duster (pictured right).

The sting operation found the bogus products slipped through the cracks, while new Energy Star partners were given access to the logo before having any of their products certified.

Companies seeking to become Energy Star partners will now only be given access to the label after receiving approval for a product.

The EPA and DOE began testing commonly used appliances last month, while also stepping up enforcement.

Thirty-five actions have been filed against manufacturers over the last five months for failing to meet Energy Star standards and rules.

"The safeguards we're putting into effect are essential for the millions of consumers who rely on Energy Star products to help save energy, money and the environment," Gina McCarthy, EPA assistant administrator for air and radiation, said in a statement.