This piece was originally published in the March 2017 issue of electroindustry.
Ken Gettman, Director, International Standards, NEMA
The Institute of Electrical and Electronic Engineers (IEEE) International Committee on Electromagnetic Safety (ICES) looked at human exposure to electromagnetic fields (EMF) and related safety provisions at a recent meeting.
ICES Technical Committee (TC) 95 addresses protection against harmful effects in humans. Among the concerns are the potential for long-term or chronic effects. These were studied extensively in the 1990s for fields developed by power lines and more recently with the widespread use of cell phones and the towers.
One standard developed under TC 95 is IEEE C95.2 Standard for Radio-Frequency Energy and Current-Flow Symbols. It is used in the posting of signs for radio-frequency safety programs when access to equipment or areas around equipment needs to be limited. IEEE ICES will update this document, particularly to harmonize it with ANSI Z535 standards.
IEEE is working on consolidating separate documents for frequencies from 0 Hz to 3 kHz, and another from 3 kHz up to 300 GHz, as was done to provide a guidance document for use by the North Atlantic Treaty Organization (NATO). IEEE C95.1-2345 Standard for Military Workplaces—Force Health Protection Regarding Personnel Exposure to EMF was implemented by NATO countries and facilitates consistent practices and policies.
The International Commission on Non-ionizing Radiation Protection (ICNIRP) develops guidance concerning human exposure to non-ionizing radiation electromagnetic fields (EMF), which includes ultraviolet, light, infrared, and radio waves, as well as infra- and ultrasound, but not x-rays or nuclear radiation. ICNIRP is currently focusing on cellular research, particularly the potential harmful effects from electrostimulation, electroporation (cell membranes), microwave hearing (a thermal effect), and temperature elevations above recognized thresholds.
IEEE ICES and ICNIRP are exchanging documents and proposals and working to harmonize the recommended levels of exposure. Both organizations rely heavily on literature review from published and peer-reviewed materials developed in the health and scientific fields. One area of significant effort in the research community is the development and refinement of body modeling to determine the extent of exposure from various sources, given the difficulty of determining actual heating impacts within the human body and the complexity of determining induced current flow.
The work of these organizations can be found throughout the world. In the European Union (EU), the Electromagnetic Fields Directive 2013/35/EU provides the minimum health and safety requirements regarding the exposure of workers to risks arising from EMF. In the United States, exposure to EMF is under the jurisdiction of several government agencies, including the Federal Communications Commission (FCC), Food and Drug Administration (FDA), and Occupational Safety and Health Administration (OSHA).
From the FDA standpoint, exposure of hospital workers in the vicinity of scanners employing strong field producing components and exposure of individuals with implanted medical devices are areas of concern. For OSHA, electric utility and factory workers where welding or electro-heating are used come under scrutiny. The FCC addresses cell towers and other broadcasting facilities where workers and perhaps untrained individuals could be exposed.
Learn more about these documents standards.ieee.org/about/get.