Specific Absorption Rate (SAR)

“the amount of RF energy absorbed by the human body when exposed to a radio frequency electromagnetic field”

A measure of the amount of RF energy absorbed by the human body when exposed to a radio frequency electromagnetic field, for instance, RF from a mobile phone. The SAR is defined as the power absorbed per mass of tissue and has units of Watts per Kilogram (W/Kg). The SAR provides a straight forward way of measuring RF exposure from a mobile phone to ensure that the phone’s RF emissions comply with the safety guidelines set by regulatory entities, for instance, the US Federal Communications Commission (FCC) and the European Committee for Electrotechnical Standardization (CENELEC). The exposure limit set by the FCC for mobile phone RF exposure is 1.6W/Kg over any 1 g of exposed tissue. CENELEC sets the limit at 2 W/kg averaged over any 10 g of exposed tissue.

Specific Absorption Rate (SAR) is described by the Federal Communications Commission (FCC) as follows:

“Working closely with federal health and safety agencies, such as the Food and Drug Administration (FDA), the FCC has adopted limits for safe exposure to radiofrequency (RF) energy. These limits are given in terms of a unit referred to as the Specific Absorption Rate (SAR), which is a measure of the amount of radio frequency energy absorbed by the body when using a mobile phone. The FCC requires cell phone manufacturers to ensure that their phones comply with these objective limits for safe exposure. Any cell phone at or below these SAR levels (that is, any phone legally sold in the U.S.) is a “safe” phone, as measured by these standards. The FCC limit for public exposure from cellular telephones is an SAR level of 1.6 watts per kilogram (1.6 W/kg).”

For more information on SAR regulations provided by the FCC, can be found here.