Who would have guessed those popular white ear buds could reduce the Apple faithful’s gene pool?

Greenpeace said in a report Monday that Apple’s iPhone ear bud cords contain chemicals considered harmful to human reproduction.

“The phthalates found in the headphone cords are classified in Europe as ‘toxic to reproduction’ because of their long-recognized ability to interfere with sexual development,” Greenpeace scientist David Santillo said in the report.

The environmental group said that while the substances are not prohibited in mobile phones, they have been banned for use in toys sold in Europe and should be removed by Apple.

The Mac maker’s popular phone contains a number of substances—internally and externally—at levels prohibited for use in young children’s toys by San Francisco, which has its own environmental standards, and by the European Union, Greenpeace said.

“Anything having to do with health should be taken seriously,” Enderle Group analyst Rob Enderle said. “It’s just one more reason to get rid of those crappy Apple ear buds and get something decent.”

The Greenpeace report, pointing out that cell phone giant Nokia has already eliminated such hazardous materials, said there is no reason why Apple’s iPhone couldn’t be made without toxins such as vinyl plastics and brominated flame retardants.

Apple CEO Steve Jobs in May 2007 promised in an essay, titled “A Greener Apple,” that the computer maker would phase out those controversial substances by the end of 2008. The iconic computer maker’s chief said that his company would eliminate the use of lead, cadmium, hexavalent chromium, cadmium, arsenic, mercury, as well as the other materials.

Mr. Jobs had also touted the computer maker’s recycling efforts, saying the company may be on track to outdo Hewlett-Packard and Dell by 2010.

Still, Apple has long been at odds with Greenpeace. In August 2006, Greenpeace gave Apple failing marks for its lack of progress in phasing out brominated flame retardants and polyvinyl chloride, used to insulate wires. And Greenpeace is a regular protester at such events as Macworld, where activists often pass out anti-Apple pamphlets.

“I know Greenpeace has been having a long-running feud with Apple,” Mr. Enderle said. “It’s kind of ironic that Al Gore is on the board.”