A smartphone must receive certification from the Federal Communications Commission (FCC) before it can be sold on the US market.
The Specific Absorption Rate (SAR) is one of the criteria that must be met by smartphone manufacturers.
SAR is defined as the power absorbed per tissue mass with units of watts per kilogram (W/kg). The current SAR standard in the US is 1.6 watts per kilogram.
No 10: T-Mobile Prism 2
Manufacturer: T-Mobile International AG SAR: 1.38
No 9: Kyocera Hydro Elite
Manufacturer: Kyocera Communications Inc SAR: 1.39
No 8: Nokia Lumia 925
Manufacturer: Nokia Oyj SAR: 1.4
No 7: ZTE Source
Manufacturer: ZTE Corporation SAR: 1.41
No 6: Nokia Asha 503
Manufacturer: Nokia Oyj SAR: 1.43
No 5: Kyocera Hydro XTRM
Manufacturer: Kyocera Communications Inc SAR: 1.44
No 4: Kyocera Hydro Edge
Manufacturer: Kyocera Communications Inc SAR: 1.48
No 3: Alcatel One Touch Evolve
Manufacturer: Alcatel-Lucent SAR: 1.49
No 2: Motorola Moto E
Manufacturer: Motorola Inc SAR: 1.5
No 1: Motorola Droid Maxx
Manufacturer: Motorola Inc SAR: 1.54