In recent years there has been considerable discussion and concern about the possible hazards of RF/MW radiation. Extensive research on this topic is underway in many countries. Natural low-frequency EM fields come from two main sources: the sun, and thunderstorm activity, but man-made fields at much higher frequencies have altered this natural EMF. At sufficiently high power densities, RF/MW energy can cause thermal effects that can cause blindness, and sterility. Non-thermal effects, such as alteration of the human body's circadian rhythms, immune system and the nature of the electrical and chemical signals communicated through the cell membrane have been demonstrated. However, none of the research has conclusively proven that low-level RF/MW radiation causes adverse health effects.
Radio-Frequency and Microwave Radiation, Third Edition. American Industrial Hygiene Association (AIHA), (2004). Provides a detailed look at the physical characteristics of radio-frequency and microwave radiation, its generation and sources, how it interacts with matter, and its biological effects. Existing standards and guidelines are discussed, as are instrumentation and controls. A handy glossary provides definitions of important terms, and an appendix presents a list of problems industrial hygienists and other health professionals might face.
Human Exposure to Radio Frequency and Microwave Radiation from Portable and Mobile Telephones and Other Wireless Communication Devices. Institute of Electrical and Electronics Engineers (IEEE) Committee on Man and Radiation (COMAR), (2000, September). Reports that sufficiently high levels of RF energy can interfere with other electronic equipment. This problem is more likely to occur with pulsed energy, which characterizes digital cellular telephones. Studies have shown that handheld cellular phones can affect the operation of heart pacemakers or defibrillators if the phone is placed directly over the device, and there have been reports of interference between cell phones and hearing aids. Individuals with pacemakers, implantable defibrillators, or other body-mounted medical electronic devices, should consult with their physician and/or the phone manufacturer to determine what precautions, if any, should be taken. Some manufacturers recommend that cell phones be used on the other side of the body from the implanted pacemaker.
Update on Cellular phone Interference with Cardiac Pacemakers. (1995, November 1). Reports interference with the pacemaker's normal delivery of pulses can occur when some cellular phones are placed very close to implanted cardiac pacemakers, The type of interference under study is called "electromagnetic interference", or "Emi". The CDRH concludes that interference issues are limited to TDMA-type digital technologies, and further, that a distance separation of ~6 inches (~15 cm) is sufficient to mitigate EMI.
American Radio Relay League (ARRL)
ARRL Handbook for Radio Amateurs. Newington CT: American Radio Relay League (ARRL), 1997.
RF Radiation and Electromagnetic Field Safety. Presents thermal and non-thermal effects, safe exposure levels, cardiac pacemakers, typical RF field strengths, and RF awareness guidelines developed by the ARRL RF Safety Committee, based on the FCC/EPA measurements and other data.
Amateur Radio RF Safety Calculator. Provides a main beam power density estimation program intended for use as part of a routine evaluation of RF safety compliance with FCC regulations. This is a World Wide Web front end for a public domain C program written by Ken Harker WM5R using the cgic library. This program has been derived directly from a public domain BASIC program written and published by Wayne Overbeck N6NB in the January, 1997 issue of CQ VHF, p. 33.
Cellular Phone Base Stations and Hand Held Cell Phones
What steps can I take to reduce my exposure to radiofrequency energy from my wireless phone? Federal Communications Commission (FCC). Recommends that users who conduct extended conversations by wireless phone every day, place more distance between their bodies and the source of the RF, since the exposure level drops off dramatically with distance. For example, use a headset and carry the wireless phone away from the body or use a wireless phone connected to a remote antenna.
"Use Of "Protective Devices" For Cellular Telephones Technical Information Statement." Institute of Electrical and Electronics Engineers (IEEE) Engineering in Medicine and Biology Magazine 21.3(2002):105-6. If a mobile-phone user wants to reduce his or her exposure to RF energy, for whatever reason, he or she can:
Limit the duration of calls
Use a digital handset instead of an older analog model. In most, but not all cases, digital handsets operate at lower power levels than analog models. (The actual power level, however, depends on local conditions and can vary greatly.)
Use "hands-free kits", which move the handset away from the body.
Human Exposure to Radio Frequency and Microwave Radiation from Portable and Mobile Telephones and Other Wireless Communication Devices. Institute of Electrical and Electronics Engineers (IEEE) Committee on Man and Radiation (COMAR), (2000, September). Indicates that local SARs produced by hand-held, transportable, and mobile transceivers and cellular telephones normally do not exceed FCC and other safety limits. Present scientific evidence, as reviewed by standards setting organizations and other expert groups, does not demonstrate health or safety risks from cellular and other communications transceivers. A potential exists for interference between hand-held units and some medical devices that may be located in close proximity to them (within a few centimeters).
Physical Agents Data Sheets (PADS) - Radiofrequency/Microwave Radiation. Alaska Department of Labor and Development. Requires employers who have people working around devices which produce radiofrequency/microwave radiation ensure that those devices are properly shielded to prevent leakage of radiation. The State of Alaska in its Alaska Occupational Safety and Health Standards has specified for incident electromagnetic energy frequencies from 10 MHz to 100 GHz, a Permissible Exposure Limit (PEL) of 10 mW/cm as averaged over any possible six-minute period.
Heating and Sealing Devices
Radiofrequency (RF) Sealers and Heaters. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 80-107, (1979, December). Reports that workers near RF sealers may be unaware of their exposure to RF emissions, because the RF energy from sealers and heaters can penetrate deeply into the body without activating the heat sensors located in the skin. The results of a NIOSH study indicate that the majority of the workers surveyed were exposed to RF energy at levels exceeding values citable by OSHA. The following controls are recommended:
Properly design and install shielding material.
Maximize the distance between the worker and the source of RF energy emission should be maximized. Examples of means to accomplish this include the use of automatic feeding devices, rotating tables, and remote materials handling.
Tune the equipment electronically to minimize the stray power emitted.
Whenever possible, equipment switch off equipment when it is not being used. Maintenance and adjustment of the equipment should be performed only while the equipment is not in operation.
After the performance of maintenance or repair, all machine parts, including cabinetry, should be reinstalled so that the equipment is intact and its configuration is unchanged.
Post warnings and information.
Develop a medical surveillance program tailored to the expected degree of employee use of RF equipment and potential for exposure to RF energy.
When these machines are used, employees should use mechanical or electrical devices that allow them to stay as far away form the source of radiation as possible.
Whenever possible, these sealers should be turned off when not being used. Maintenance and adjustment of this type of equipment should be performed only by trained technicians and only when the machines are turned off.
Warnings should be posted to keep everyone away from the source of radiation except for those workers who are absolutely essential to performing the job.
Microwave Ovens and their Hazards. Canadian Centre for Occupational Health and Safety (CCOHS). Identifies old or faulty door seals as the most common causes of microwave radiation leakage. Mechanical abuse, a build-up of dirt, or simple wear and tear of continued use can cause door seals to be less effective. Theoretically, there will be small amounts of leakage through the viewing glass but measurements have shown this to be insignificant. Safety tips for installation and maintenance of microwave ovens include:
Take special care to ensure that no damage occurs to the part of the oven making contact with the door or door seals.
Ensure that the microwave is unplugged or disconnected from electrical power before reaching into any accessible openings or attempting any repairs.
Ensure that the adjustment of applied voltages, replacement of the microwave power generating component, dismantling of the oven components, and refitting of waveguides are undertaken only by persons who have been specially trained for such tasks. The services of a qualified repairman should be sought when any malfunction is suspected.
Do not by pass the door interlocks.
Do not test a microwave power generating component without an appropriate load connected to its output. The power generated must never be allowed to radiate freely into occupied areas.
Microwave Oven. US Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH). Contains FAQs about microwave ovens, checking ovens for leakage, tips on safe microwave oven operation, and the erupted Hot Water Phenomena in Microwave Ovens.
Radio Broadcast Antennae
Notice of Apparent Liability for Forfeiture (PDF). Federal Communication Commission (FCC), (2005, January 6). Describes a violation of FCC rules resulting in a $10K fine. The case involves a worker climbing an FM broadcast tower.
Traffic Radar Devices
Occupational Exposure of Police Officers to Microwave Radiation from Traffic Radar Devices. National Institute for Occupational Safety and Health (NIOSH), National Technical Information Service (NTIS) Publication No. PB95-261350, (1995, June). Recommends police officers take some simple steps which will sharply reduce their exposure to the low-level microwave radiation which these devices emit.
Always point the device away from the police officer's body, or his/her partner's body, while it is turned on.
Mount fixed radar antennas so that the beam is not pointed at any occupant of the patrol car.
Whenever possible, turn off a hand-held unit when it is not in use. If the police officer's unit has a "standby" mode, always use it when not measuring the speed of a vehicle. Never rest the unit against the officer's body when it is turned on.
When it is on, try to avoid pointing the device toward metal surfaces inside the police officer's car, such as the floor or a door, to avoid microwave reflection.
All other documents, that are not PDF materials or formatted for the web, are available as Microsoft Office® formats and videos and are noted accordingly. If additional assistance is needed with reading, reviewing or accessing these documents or any figures and illustrations, please also contact OSHA's Directorate of Technical Support and Emergency Management at (202) 693-2300.
**eBooks - EPUB is the most common format for e-Books. If you use a Sony Reader, a Nook, or an iPad you can download the EPUB file format. If you use a Kindle, you can download the MOBI file format.
U.S. Department of Labor | Occupational Safety & Health Administration | 200 Constitution Ave., NW, Washington, DC 20210 Telephone: 800-321-OSHA (6742) | TTY www.OSHA.gov
Thank You for Visiting Our Website
You are exiting the Department of Labor's Web server.
The Department of Labor does not endorse, takes no responsibility for, and exercises no control over the linked organization or its views, or contents, nor does it vouch for the accuracy or accessibility of the information contained on the destination server. The Department of Labor also cannot authorize the use of copyrighted materials contained in linked Web sites. Users must request such authorization from the sponsor of the linked Web site. Thank you for visiting our site. Please click the button below to continue.