§  1.1310   Radiofrequency radiation exposure limits.

   (a) Specific absorption rate (SAR) shall be used to evaluate the
   environmental impact of human exposure to radiofrequency (RF) radiation
   as specified in § 1.1307(b) of this part within the frequency range of
   100 kHz to 6 GHz (inclusive).

   (b) The SAR limits for occupational/controlled exposure are 0.4 W/kg,
   as averaged over the whole body, and a peak spatial-average SAR of 8
   W/kg, averaged over any 1 gram of tissue (defined as a tissue volume in
   the shape of a cube). Exceptions are the parts of the human body
   treated as extremities, such as hands, wrists, feet, ankles, and
   pinnae, where the peak spatial-average SAR limit for
   occupational/controlled exposure is 20 W/kg, averaged over any 10 grams
   of tissue (defined as a tissue volume in the shape of a cube). Exposure
   may be averaged over a time period not to exceed 6 minutes to determine
   compliance with occupational/controlled SAR limits.

   (c) The SAR limits for general population/uncontrolled exposure are
   0.08 W/kg, as averaged over the whole body, and a peak spatial-average
   SAR of 1.6 W/kg, averaged over any 1 gram of tissue (defined as a
   tissue volume in the shape of a cube). Exceptions are the parts of the
   human body treated as extremities, such as hands, wrists, feet, ankles,
   and pinnae, where the peak spatial-average SAR limit is 4 W/kg,
   averaged over any 10 grams of tissue (defined as a tissue volume in the
   shape of a cube). Exposure may be averaged over a time period not to
   exceed 30 minutes to determine compliance with general
   population/uncontrolled SAR limits.

   (d)(1) Evaluation with respect to the SAR limits in this section must
   demonstrate compliance with both the whole-body and peak
   spatial-average limits using technically supported measurement or
   computational methods and exposure conditions in advance of
   authorization (licensing or equipment certification) and in a manner
   that facilitates independent assessment and, if appropriate,
   enforcement. Numerical computation of SAR must be supported by adequate
   documentation showing that the numerical method as implemented in the
   computational software has been fully validated; in addition, the
   equipment under test and exposure conditions must be modeled according
   to protocols established by FCC-accepted numerical computation
   standards or available FCC procedures for the specific computational
   method.

   (2) For operations within the frequency range of 300 kHz and 6 GHz
   (inclusive), the limits for maximum permissible exposure (MPE), derived
   from whole-body SAR limits and listed in Table 1 in paragraph (e)(1) of
   this section, may be used instead of whole-body SAR limits as set forth
   in paragraphs (a) through (c) of this section to evaluate the
   environmental impact of human exposure to RF radiation as specified in
   § 1.1307(b) of this part, except for portable devices as defined in
   § 2.1093 of this chapter as these evaluations shall be performed
   according to the SAR provisions in § 2.1093.

   (3) At operating frequencies above 6 GHz, the MPE limits listed in
   Table 1 in paragraph (e)(1) of this section shall be used in all cases
   to evaluate the environmental impact of human exposure to RF radiation
   as specified in § 1.1307(b) of this part.

   (4) Both the MPE limits listed in Table 1 in paragraph (e)(1) of this
   section and the SAR limits as set forth in paragraphs (a) through (c)
   of this section are for continuous exposure, that is, for indefinite
   time periods. Exposure levels higher than the limits are permitted for
   shorter exposure times, as long as the average exposure over a period
   not more than the specified averaging time in Table 1 in paragraph
   (e)(1) is less than (or equal to) the exposure limits. Detailed
   information on our policies regarding procedures for evaluating
   compliance with all of these exposure limits can be found in the most
   recent edition of FCC's OET Bulletin 65, “Evaluating Compliance with
   FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic
   Fields,” and its supplements, all available at the FCC's internet
   website: https://www.fcc.gov/general/oet-bulletins-line, and in the
   Office of Engineering and Technology (OET) Laboratory Division
   Knowledge Database (KDB) (https://www.fcc.gov/kdb).

   Note to paragraphs (a) through (d): SAR is a measure of the rate of
   energy absorption due to exposure to RF electromagnetic energy. These
   SAR limits to be used for evaluation are based generally on criteria
   published by the American National Standards Institute (ANSI) for
   localized SAR in Section 4.2 of “IEEE Standard for Safety Levels with
   Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3
   kHz to 300 GHz,” ANSI/IEEE Std C95.1-1992, copyright 1992 by the
   Institute of Electrical and Electronics Engineers, Inc., New York, New
   York 10017. These criteria for SAR evaluation are similar to those
   recommended by the National Council on Radiation Protection and
   Measurements (NCRP) in “Biological Effects and Exposure Criteria for
   Radiofrequency Electromagnetic Fields,” NCRP Report No. 86, Section
   17.4.5, copyright 1986 by NCRP, Bethesda, Maryland 20814. Limits for
   whole body SAR and peak spatial-average SAR are based on
   recommendations made in both of these documents. The MPE limits in
   Table 1 are based generally on criteria published by the NCRP in
   “Biological Effects and Exposure Criteria for Radiofrequency
   Electromagnetic Fields,” NCRP Report No. 86, Sections 17.4.1, 17.4.1.1,
   17.4.2 and 17.4.3, copyright 1986 by NCRP, Bethesda, Maryland 20814. In
   the frequency range from 100 MHz to 1500 MHz, these MPE exposure limits
   for field strength and power density are also generally based on
   criteria recommended by the ANSI in Section 4.1 of “IEEE Standard for
   Safety Levels with Respect to Human Exposure to Radio Frequency
   Electromagnetic Fields, 3 kHz to 300 GHz,” ANSI/IEEE Std C95.1-1992,
   copyright 1992 by the Institute of Electrical and Electronics
   Engineers, Inc., New York, New York 10017.

   (e)(1) Table 1 to § 1.1310(e)(1) sets forth limits for Maximum
   Permissible Exposure (MPE) to radiofrequency electromagnetic fields.

   Table 1 to § 1.1310(e)(1)—Limits for Maximum Permissible Exposure (MPE)
   Frequency
   range
   (MHz) Electric field strength
   (V/m) Magnetic field strength
   (A/m) Power density
   (mW/cm^2) Averaging
   time
   (minutes)
              (i) Limits for Occupational/Controlled Exposure
             0.3-3.0                614    1.63   *(100)      ≤6
             3.0-30                 1842/f 4.89/f *(900/f^2)  <6
             30-300                 61.4   0.163  1.0         <6
             300-1,500                            f/300       <6
             1,500-100,000                        5           <6
             (ii) Limits for General Population/Uncontrolled Exposure
             0.3-1.34               614    1.63   *(100)     <30
             1.34-30                824/f  2.19/f *(180/f^2) <30
             30-300                 27.5   0.073  0.2        <30
             300-1,500                            f/1500     <30
             1,500-100,000                        1.0        <30

   f = frequency in MHz. * = Plane-wave equivalent power density.

   (2) Occupational/controlled exposure limits apply in situations in
   which persons are exposed as a consequence of their employment provided
   those persons are fully aware of the potential for exposure and can
   exercise control over their exposure. The phrase fully aware in the
   context of applying these exposure limits means that an exposed person
   has received written and/or verbal information fully explaining the
   potential for RF exposure resulting from his or her employment. With
   the exception of transient persons, this phrase also means that an
   exposed person has received appropriate training regarding work
   practices relating to controlling or mitigating his or her exposure. In
   situations when an untrained person is transient through a location
   where occupational/controlled limits apply, he or she must be made
   aware of the potential for exposure and be supervised by trained
   personnel pursuant to § 1.1307(b)(2) of this part where use of time
   averaging is required to ensure compliance with the general population
   exposure limit. The phrase exercise control means that an exposed
   person is allowed and also knows how to reduce or avoid exposure by
   administrative or engineering work practices, such as use of personal
   protective equipment or time averaging of exposure.

   (3) General population/uncontrolled exposure limits apply in situations
   in which the general public may be exposed, or in which persons who are
   exposed as a consequence of their employment may not be fully aware of
   the potential for exposure or cannot exercise control over their
   exposure. For example, RF sources intended for consumer use shall be
   subject to the limits for general population/uncontrolled exposure in
   this section.

   [ 85 FR 18145 , Apr. 1, 2020]