This article was originally published by RFID Update.
March 28, 2007—Everything from wireless networks to cell phones to electric shavers has been subjected to media hand wringing about potential dangers from exposure. These stories have generally overstated the risk, but certainly when there is excessive exposure to electromagnetic fields (EMF) there could be a health risk concern. The key factors are the amount of energy, the proximity to the source, the length of exposure, and the frequency. RFID devices, like the aforementioned consumer products, are deemed safe under recommended implementation approaches, but buyers should take appropriate precautions.
EPCglobal, specifically the Health and Science Public Policy Committee, has looked at an exhaustive body of research related to EMF exposure aggregated by the World Health Organization (WHO), the International Commission on Non Ionizing Radiation Protection (ICNIRP), and others. With the current scientific understanding, the general conclusion that can be drawn is that exposures below the recommended levels pose no health risk. As to RFID specifically, an occupational EMF audit conducted in Australia looked at various warehouse implementation scenarios and demonstrated that when the proximity was near contact (less than one centimeter), the exposure was between 45 and 75 percent of the recommended limit. At 20 centimeters away, that percentage drops to a range of 2 to 25 percent, then drops precipitously to between 1 and 8 percent at 40 centimeters (nearly 16 inches). Some reader manufacturers include advisories in their packaging to keep antennae 22 centimeters from employees and the public.
There is a large body of work in this area that has been reviewed by the scientific community, regulatory agencies, and other interested parties. However, there needs to be more study that looks more specifically at RFID technology in typical occupational and public deployments. What concerns us is the possibility that some implementations take measures to improve efficacy. Utilizing higher power levels, continuous power for readers in close proximity, and increasing the density of readers are all techniques for improving performance, and there isn’t enough data on how this impacts exposure levels.
Many of the existing studies were relative to the effects of mobile phones, which are usually in closer proximity to the user than RFID readers but have lower power and shorter exposure times. A large amount of research was underwritten by Motorola and, despite an obvious vested interest in demonstrating that mobile phones are safe, the work has been vetted and is generally respected by the larger scientific community. Motorola continues to support research on the biological and health effects of RF exposure through the Mobile Manufacturers Forum. Again, what is needed is more study on specific RFID device implementation scenarios.
Essential Guidance
Reader manufacturers and the implementing businesses must be diligent and pre-emptive as they carry the liability should a hazard become known. The analysis of EMF exposure limits is extremely complex and depends on a large range of variables. Therefore we provide some essential guidance for companies using RF equipment. Until there is more study, we recommend the following:
- When selecting readers for an implementation, make sure the vendor can verify compliance with accepted standards. Similarly, installation service providers should have experience with RF and understand how to minimize exposure. If you want an added level of protection, request that your vendors indemnify you from any future health claims resulting from use of the technology.
- Stay informed of the guidance offered by regulatory and standards bodies such as the ITU, WHO, IEEE, OSHA, and ICNIRP. Educate your employees on safe practices and reinforce this training with signage. If implementing in a public space, companies should pay particular attention to the limits in national regulations and international recommended guidelines, which differ from the limits in occupational spaces.
- Take specific readings of EMF levels after initial installation and when equipment is added or replaced to assure compliance with standards. Perform regular audits to verify continued compliance and make sure that the hardware is properly maintained.
- Balance the need for read efficacy with exposure levels. Use lower power levels if possible. Shut down antennae when not in use and activate with motion sensors as an alternative to always-on operation. Work around issues with dead spots rather than simply increasing the density of the readers.
There is no reason to stall RFID implementation projects. Taking appropriate measures, however, will mitigate risk and preemptively address any fears that may be raised by employees or consumers. For further reference, EPCglobal released EPCglobal Recommended Occupational Use Best Practices for Complying with Limits on Human Exposure to Electromagnetic Fields in January.