Where did our RF standards come from?

The American National Standards Institute (ANSI) sets voluntary safety standards for products and materials ranging from motorcycle helmets to buildings.  One particular ANSI standard, ANSI C95.1, sets guidelines for human exposures to RF energy.  In 1992, this standard was revised to reflect the latest in research findings.  The limit for public exposure was set at a level 50 times below the observed threshold of physical effects.  While the possibility exists that there may be some as yet unknown adverse effects caused by a long-term mechanism, there have been no definitive findings in this area and no standards have been proposed for such low exposure conditions.

The Federal Communications Commission (FCC), the regulatory body for radio transmitting stations, has adopted the RF exposure guidelines published in a 1986 report by the National Council on Radiation Protection and Measurements (“NCRP-86”).  The NCRP-86 recommendations are similar to those adopted in ANSI C95.1-1992, and at PCS frequencies are even more restrictive.  Though the effective date for applying the NCRP standard to FCC licenses is September 1, 1997, the most conservative approach is to use the most restrictive applicable limit of the NCRP standard to evaluate cellular, PCS, and other transmitting facilities. 

The standards in the U.S. are very similar to those in Europe, Canada, Australia, etc, since all the standard-setting bodies around the world are looking at the same set of data from hundreds of published research studies, spanning decades of inquiry in industry and academia.  The standards incorporate a 50-times safety factor, judged by those independent bodies to be a prudent margin of protection for all members of the public – old or young, large or small, healthy or inform – for continuous exposure:  24 hours a day, seven days a week.

Our reports and measurements always express RF exposure levels as a percentage of the FCC limit.  For example, a proposed site may be 1% of the most restrictive public limit.  This does not mean that there is a 1% health risk.  Rather, it means that it is only 1% of the FCC’s RF limit.