MANAGING BEST PRACTICES: EMF exposures: Keep pace with new info
February 5, 2009
How much EMF exposure did you receive today?
According to NIOSH you may have received between 0.1-7 milligauss (mG) by just sitting at your desk. If you were near an electrical resistance heater, your electromagnetic field (EMF) exposure could have reached 14,000 mG. It all adds up â€” but when do these exposures become a problem?
European legislationEurope is leading the way in addressing EMF workplace safety and health risks. The U.S. has no national or state legislation (and none is on the horizon) to address workplace EMF exposure. Member states in the EU, however, originally had until April 2008 to establish EMF legislation under Directive 2004/40/EC. This Directive requires all employers to measure workplace EMF exposure, determine if action values or exposures limits are exceeded, and institute controls (e.g. distance, shielding, and training). The implementation date has been pushed back until 2012 due to common magnetic resonance imaging (MRI) exposures exceeding limits.
Guidance from the NetherlandsThe Ministry of Social Affairs and Employment in the Netherlands prepared an extensive report that shows how the EU Directive on EMF is to be carried out at a Member State level. The report “Electromagnetic Fields in the Working Environment (June 2006)” is found at http://www.rivm.nl/bibliotheek/ rapporten/610015001.pdf.
What’s particularly good about the Netherlands report is that it provides a list of processes unlikely to exceed EMF action values, such as the use of office equipment and cell phones. The following are examples of equipment and processes that warrant EMF measurements: electrical installation and maintenance; dielectric heating (plastic sealers and wood gluing equipment); electrochemical processes (e.g. electroplating); induction heating (open coils or furnaces); welding (manual arc welding, cable and electrode holder, spot and induction welding); non-destructive magnetic testing.
Address curiosityThe public’s curiosity about EMF is growing. Curiosity is the first stage in risk communication; followed by the stages of concern, controversy, and conflict. Do not ignore an employee’s simple inquiry about EMF. If an employee’s curiosity is satisfied, then all is well. Do whatever you can to avoid conflict.
You may satisfy employee curiosity about EMF through your better understanding of the topic. The first place to start is by being thoroughly familiar with the Q&As in the NIEHS/ DOE EMF RAPID report found at http://www. niehs.nih.gov/health/topics/agents/emf/. Next, master the information in the Netherland’s report above.
EMF measurementsMeasuring EMF can be deceptively simple. For example, an “E-Alert” home inspection meter can be purchased online for $29.95 from the EMF Superstore at http://www.lessemf. com/. This meter is equipped with green (safe), yellow (caution), and red (warning) lights. The yellow light means magnetic flux densities between 2.5-8 mG are detected and the red light indicates magnetic flux densities exceed 8 mG. Meters such as this allow some people in the home inspection market to conduct surveys for EMF “hot spots.”
In reality, measuring for EMF and interpreting exposure at the workplace may be very involved. If you want to determine, for example, if action values are exceeded from EU Directive 2004/40/ EC, measurements must include electric field strength, magnetic field strength, magnetic flux density, equivalent plane wave power density, and contact current; and, these measurements must be determined for 13 frequency ranges (ranging from 0-1Hz to 2-300 GHz).
TLVs® for 8-hour TWA and ceiling values include EMF measurements for whole-body exposure, arms and legs, hands and feet, whole body and partial body, and point of contact current limits. TLVs® may vary depending upon calculations based upon the EMF frequency encountered.
Although there is no workplace EMF legislation in the U.S., and none appears imminent, you should determine if actions by the EU and other countries (e.g. Japan has workplace legislation on EMF) are a best practice that should be implemented at your workplace. At the very minimum, since exposure and concerns with EMF are certain to grow, you need to grow your knowledge on this topic.