A Summary of the Report and Order in ET Docket 93-62
By Wayne Overbeck, N6NB
woverbeck@ccvax.fullerton.edu
August 3, 1996
This is a summary of the FCC's new RF safety rules, which
were approved on August 1, 1996:
1) When the new rules go into effect next January 1, Amateur
Radio stations will no longer be categorically exempt from
complying with the FCC's RF safety standards. However,
individual amateurs will not be required to perform the
complex environmental assessments that are required of
many other FCC licensees.
2) The standards for RF safety that amateurs (and other FCC
licensees) will be required to meet are a combination of the
1992 ANSI/IEEE standards and somewhat stricter standards
developed by the National Council for Radiation Protection
and Measurement. The standards establish limits for human
exposure to RF fields; the permissible field strength (or
"power density") varies by frequency. The lowest power
density is allowed in the 30-300 MHz range. At those frequencies, the exposure limit is 1.0 milliwatt per square
centimeter in "controlled environments" (averaged over any
six-minute period) and 0.2 milliwatts per square centimeter
in "uncontrolled environments" (averaged over any 30-minute
period). Amateurs' own households will fall under the
standards for controlled environments, while RF fields in
other areas such as neighbors' homes must not exceed the
stricter limits that apply in uncontrolled environments.
3) Amateurs whose output power exceeds 50 watts will be
required to evaluate their station configurations (including
power output, antenna gain, frequency, proximity of the antenna
to inhabited areas, and duration of transmissions) to assure
compliance with the new rules.
4) The FCC will publish charts and tables to help amateurs
determine that their installations and operating parameters
comply with the rules. There will be examples showing
safe distances from various kinds of antennas with various
combinations of frequency, power output and transmission
duration.
5) Five questions concerning RF safety are to be added to each
of three Amateur Radio examination elements (elements 2, 3A and
and 3B). Application forms for new licenses and renewals will
require amateurs to certify that they have read and understand
the new RF safety requirements.
6) As a practical matter, the new rules will NOT require most
amateurs to modify their stations. The FCC conducted a
survey of RF fields near amateur radio stations in 1990 and
concluded that only a few station configurations may result in
exposures that would exceed the new standards. Potential
problem areas may include some high power mobile installations,
antennas located indoors or close to neighbors' units in
apartments and condominiums, and high power VHF-UHF stations
using very high gain antennas pointed toward an immediately
adjacent dwelling unit. Typical amateur stations using
directional antennas about 35 feet above the ground (or higher)
do not produce fields that exceed the new standards even at the
kilowatt level. The FCC's measurements indicated that my own
home station would not violate the new standards even with
the tower fully telescoped to 25 feet.
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Page last modified: 10:49 AM, 19 Mar 2000 ET
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