Techcrunch points to a Youtube Video from Greenpeace which claims that Apple's iPhone has a high level of "toxic brominated compounds" and "hazardous PVCs".
In the video, Greenpeace calls for Apple to produce a more environmentally friendly iPhone. An online document details their findings. It should be noted that the iPhone does appear to be "compliant with the requirements of the EU's Directive on use of certain hazardous substances in electronics and electrical goods" based on the chemicals tested, but the paper still lists a number of potential concerns.
Update: A PDF of Greenpeace's claims can be found here.