Cell phones contain hazardous materials, that isn’t a secret. In fact, research firms iFixit and HealthyStuff regularly test brand new smartphone models for toxins such as mercury, lead and bromine, among a total of 12 common toxins found in smartphones. The group recently took the iPhone 5 into their labs and put it to the test. The result? It’s one of the “low concern” devices. Not bad Apple, considering the second generation iPhone holds the spot as the worst rated smartphone.

The iPhone 5 joins the Motorola Citrus, the iPhone 4S, the LG Remarq, the Samsung Captivate and the Samsung Evergreen in the “low risk” category. The high-risk phones include the Palm Treo 750, the BlackBerry Storm 9530, the Nokia N95, the Motorola MOTO W233 Renew, the Palm m125 and the aforementioned second generation iPhone.

“The HealthyStuff analysis demonstrates that Apple is actively reducing toxic chemicals in their products,” the group recently. “The iPhone has undergone a steady, gradual toxic chemical improvement in the last five years: the iPhone 2G received the worst overall score of all ranked phones, but the iPhone 4 and 5 are now among the top ten percent of phones.” The overall ranking, however, doesn’t mean that the phone doesn’t have dangerous aspects.

“Also worthy of note, phones that scored well overall did not necessarily fare well in every category,” the group explained. “The “low concern” Samsung Reclaim had a “high concern” proportion of arsenic. Twenty-four of the phones (nearly 70%) had a “high concern” proportion of copper.”

iFixit and HealthyStuff said that there’s still plenty of room for improvement and that we need to encourage manufacturers to clean up their act when it comes to making smartphones. We also need to recycle more, otherwise phones may end up being burned in landfills, which obviously poses insane safety risks.

[via GigaOm, iFixit]