Special about Specific Absorbtion Rate (SAR)
 Tech.
 Track
Issued by: Teleconformity
Number: TCMY-003
Publication date: 2010-10-05
Author: CEO
FCC RF Exposure

For Portable devices (devices that can be used and weared with you in the proximity of the body, lap, hands, wrist, feet, ankles, face, ear, etc.), FCC Routine Evaluation for SAR is required in case the source-based time-averaged power (average conducted power or average radiated EIRP, whichever is the highest) between the Low and High treshold in the table below. Below the Low treshold, no Routine Evaluation is required. Routine Evaluation refers to the requirements specified in 47 CFR part 2.1093, using measurements or computer simulation.
Exposure categoryLow treshold (mW)High treshold (mW)
General population
(Uncontrolled)		60 / f when d < 2.5 cm
120 / f when d ≥ 2.5 cm		900 / f when d < 20 cm
Occupational
(Controlled)		375 / f when d < 2.5 cm
900 / f when d ≥ 2.5 cm		2250 / f when d < 20 cm
f shall be the mid-band frequency expressed in GHz; the limit calculated with this mid-band frequency applies to all channels. For PTT with body-worn or face-held modes, d is the distance from the device case to a parsons body; for modules with antennas inside laptops, d is the distance from the antenna to the persons body.

If not below the Low threshold, please refer to the SAR test procedures as published in the FCC KDB, applying the SAR limits from 47 CFR part 2.1093 in the table below:
Exposure categoryWhole-Body
averaged over entire body		Partial-Body
averaged over 1 gram of tissue		Hands, Wrists, Feet, Ankles
averaged over 10 gram of tissue
General population
(Uncontrolled)		0.08 W / Kg1.6 W / Kg4 W / Kg
Occupational
(Controlled)		0.4 W / Kg8 W / Kg20 W / Kg
Note 1: Above 6 GHz, SAR limits are not applicable and MPE limits should be applied at 5 cm or more.
Note 2: Time-averaging for field strength and power density does NOT apply for the general population.
Note 3: The controlled limits cannot be used to evaluate Part 15 devices!
Note 4: All estimates and calculations should be made with the highest gain antennna!

For Mobile devices, usually a 20 cm safety distance is taken to calculate the exposure of the device against the Maximum Permissible Exposure (MPE) limits. For calculation, the far field suitable Friis formulae is a common approach and acceptable to include in your filing. Make sure that your device is recognized as a mobile device. You cannot freely choose and consider just any EUT to be a mobile device!
Friis formulae: PowerDensity = OutputPower [mW] * AnennaGain [linear] / (4*pi*distance2) [mW / cm2]
Exposure category300 MHz - 1500 MHz (mW/cm2)1500 MHz - 100 GHz (mW/cm2)
General population
(Uncontrolled)		f / 1500 over 6 min1 over 30 min
Occupational
(Controlled)		f / 300 over 6 min5 over 6 min
f shall be expressed in MHz. Limits as specified in 47 CFR 1.1310.

The Maximum Permissible Exposure (MPE) limits at each frequency for electric field strength [V/m] and magnetic field strenght [A/m] are specified in Table 1 of
(Uncontrolled) OET65b


Articles by Teleconformity

Find below a summary of SAR publications for FCC, IC, R&TTE, MIC Japan, Australia and Brazil.



Related information published by the authorities:

FCC information about RF safety (including references to SAR levels of mobile phones)
Industry Canada information on RF Engergy and Health
▸ Guidelines (GL-02) for the protection of the general public in compliance with Safety Code 6.
MIC Japan information regarding Biological effects of Radio
European Policy on RF exposure (DGSANCO)
▸ European Publications on EM fields
▸ European Report on the implementation of Council Recommendation 1999/519/EC (May 2010)


International:

SCENIHR Report on Health Effects to EMF (November 2009)
INCHEM overview 137 regarding Health Criteria on EMF (300Hz-300GHz)
Australian ARPANSA Radio Protection Standard / ACA 2003 (3kHz-300GHz)
Knowledge Platform EMF, Netherlands - Kennis Platform ElectroMagnetische Velden



For more information on this subject, or comments, please contact Teleconformity.

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