On December 4, 2019, the FCC released a notice regarding a report and order as well as proposed rulemaking on RF exposure limits. In this notice, the FCC also declines requests to increase/decrease existing RF exposure limits as well as a petition to treat the outer ears separately from other extremities in regard to RF exposure limits. In this notice, the FCC performs the following:
Revises implementing rules to reflect modern technology.
Updates existing criteria for determining when a licensee is exempt from RF exposure evaluation criteria.
Provides more flexibility for licensees to establish compliance with RF exposure limits.
Provides methods that RF equipment operators can use to mitigate the risk of excess exposure.
Proposes an additional limit for localized RF exposure.
Proposes methodologies for compliance for portable devices operating at high GHz frequencies and an extension to THz frequencies as well.
Proposes the acceptance of WPT equipment under Parts 15 and 18.
In the Second Report and Order, the FCC adopts new methods for the determination and demonstration of compliance with standards. This report and order does not revise existing RF exposure limits. The following three subjects are addressed in the Second Report and Order: exemptions from RF exposure evaluation requirements; clarification regarding measurement methodologies used to determine potential RF exposure levels in cases in which no exemptions apply; and post-evaluation mitigation procedures to prevent exposure to RF emissions beyond the established exposure limit.
Exemptions from RF Exposure Evaluation Requirements The FCC has adopted proposals from the 2013 RF Further Notice in order to revise criteria governing exemption from RF evaluation requirements. The new exemption criteria applies to all rules authorizing RF sources. A device is exempt from RF exposure evaluation requirements if it meets one of the following criteria:
Low-power devices that transmit at no greater than 1 mW
Higher-power devices with transmitter antennas that operate within 40 cm of the body and
All other transmitters based on a set of formulas for MPE limits.
In addition, exemption requirements are further separated into single and multiple RF sources. View the official notice to read through all exemption criteria.
Under these rules, licensees and applicants seeking equipment authorization who seek exemption must use the calculations provided to determine whether or not the device or transmitter meets the above criteria for exemption. If the device or transmitter does not meet the above criteria, a routine evaluation for compliance with RF exposure rules is required.
The FCC emphasizes that these rules do not require Part 15 devices—except those operating under the provisions of Sections 15.255, 15.257, 15.319, and 15.407—to provide a routine environmental RF exposure evaluation prior to equipment authorization. The Commission, however, does require an evaluation where there is a potential for RF exposure caused by either higher-power emissions or operation in close proximity to users (ex: Wi-Fi routers used in residential environments).
Measurement Methodologies to Determine RF Exposure Limits when Exemptions do not Apply
For fixed RF sources in which exemption does not apply, routine environmental evaluation must be performed. In most cases, this evaluation does not require the determination of a precise exposure level. For cases in which more precise calculations are require, the FCC emphasizes that ensuring human safety is the most important factor. The FCC has removed requirements specifying acceptable approaches to evaluation. These will be superseded by any valid computational method to determine compliance with RF exposure limits. To find a list of acceptable methods, you can visit the OET Bulletins and KDB.
In addition to this change, the FCC has eliminated a minimum measurement distance of 5 cm for devices operating above 6 GHz.
In regard to responsibility, the FCC recognizes that an entity responsible for new construction or the modification of existing facilities could bring a compliant site out of compliance. All licensees subject to Section 1.1307(b) responsibility for maintaining compliance and the obligation to bring a previously-compliant sites back into compliance. If an environmental change or other external factor occurs that brings a site out of compliance, all licensees share the responsibility for any modification or remediation necessary to bring the site into compliance. Finally, if a site is found out of compliance, a licensee that can demonstrate that its facility was compliant and did not cause the non-compliance will not be liable in an enforcement proceeding relating to the period of non-compliance.
Other Updates to RF Exposure Requirements:
For applicants for equipment authorizations covered by Parts 15 and 18, in Sections 15.212(a)(viii), 15.247(i), 15.255(g), 15.257(g), 15.319(i), 15.407(f), 15.709(h), and 18.313: the general exemption criteria for the specific exemption from routine evaluation will be substituted.
For applicants and licensees in the Public Mobile Service Personal Communications Service: general exemption criteria for the specific exemption from routine evaluation will be substituted in Sections 22.379 and 24.52.
For applicants and licensees of satellite earth stations: the 5 percent criterion in Section 25.117(g) will be removed and similar language will be incorporated into Section 25.115, paragraph (p), Section 25.129, paragraph (c), Section 25.149, paragraph (c)(3), and Section 25.271, paragraph (g).
For applicants and licensees in the Miscellaneous Wireless Communications Services, Radio Broadcast Services, and Private Land Mobile Services: general exemption criteria for the specific exemption from routine evaluation will be substituted by modifying Section 27.52 and Section 73.404, paragraph (e)(10) and by adding Section 90.223 and removing Section 90.223.
Mobile devices have been added to Section 95.2385 for WMTS and Section 95.2585 has been revised to eliminate the limited specification of FDTD modeling for MedRadio service medical implants.
For applicants and licensees in the Amateur Radio Service: general exemption criteria for the specific exemption from routine evaluation based on power alone will be substituted in Section 97.13(c)(1) and the use of occupational/controlled limits for amateurs will be specified.
For applicants and licensees in the Multichannel Video Distribution and Data Service: general exemption criteria for the specific exemption from routine evaluation of stations in the 12.2-12.7 GHz frequency band with output powers less than 1640 watts EIRP will be substituted in Section 101.1425.
Notice of Proposed Rulemaking In this notice, the FCC seeks comment on the following:
The expansion of the range of frequencies for which RF exposure limits apply
The incorporation of rules regarding localized exposure limits above 6 GHz parallel to the localized exposure limits established below 6 GHz
The specification of conditions under which and methods by which limits are averaged (in time and area) during the compliance evaluation and
New issues raised by WPT devices.
Comments to the proposals delineated in the notice are due by January. Please see the official notice to view a detailed description of the FCC’s proposals.