For 1.6 SAR cellphone, the limit is based upon a cell phone call that averages 30 minutes when the cell phone is held at the ear. For cellphones with low SAR, even though it has low SAR, if you use your cell phone for couple or more hours, the result will be the same.
Holding a phone away from the body or using a wired earpiece lowers the amount of radiation absorbed, and text messaging rather than talking, further lowers the amount.
These are the Top List Cellphone Units and its SAR:
Watch the video below...