The Center for Environmental Health in Oakland, California, sent Apple notice on Monday after environmental activist group Greenpeace released a scientific analysis of how Earth-friendly iPhones are.

In a YouTube video posted at the Greenpeace website, scientist David Santillo claims that iPhones contain dangerous levels of bromine, chlorine and "phthalates," chemical compounds used to increase the flexibility of plastic.

"Electronics companies have traditionally relied on the cool clean image of their devices in order to sell them," Santillo says in the video, which starts with Apple chief executive Steve Jobs ebulliently announcing the iPhone launch.

"What we have found over the years is that once you get behind that shiny cover the story is very different."

The level of phthalate esters, a chemical linked to birth defects, in plastic coating of iPhone earphones wires is greater than that allowed in toys or childcare items sold in Europe, according to Greenpeace.

"If a pregnant woman is winding and unwinding that cord a number of times each day, like we all would, she is getting exposed to this chemical," center chief executive Michael Green told AFP.

"That is a big piece of our concern."

The notice sent to Apple and the California state attorney general gives the nonprofit environmental law group legal standing to sue Apple in 60 days.

A lawsuit could compel Apple to put warnings on iPhone packaging but doesn't require the renowned maker of iPods and Macintosh computers to recall devices or alter the composition of models yet to be sold.

"There are chemicals in some of the parts that come with the iPhone that are well known in California to cause birth defects," Green said. "We want those chemicals out."

The center's experience in "hundreds of different cases" is that companies prefer to get rid of offending chemicals rather than taint images of brands with health warnings, according to Green.

"No sense warning people when they can just use different chemicals to make it so no one is exposed to toxins," Green said.

"It's a better business decision. Especially with Apple, because its brand is so valuable."

Apple declined to discuss the matter with AFP on the grounds it doesn't comment on pending litigation.

Apple products conform to rigorous standards set in the European Union and the Northern California company has vowed to eliminate PVC and bromines connected to fire retardants from its model line by the end of the year.

Environmentalists contend that the greening of Apple is long overdue, with the company lagging behind rivals when it comes to eliminating toxins and supporting recycling or safe disposal of products.

Greenpeace also criticized Apple for having batteries glued and soldered into iPhones, making it harder to replace, recycle or properly dispose of the chemically hazardous power packs.