Electromagnetic Field Safety Standards

IAP Research makes Magnepress^® equipment that uses pulsed magnetic forces to form metals and compact powder materials. One concern that is sometimes raised is that exposing people to the pulsed electric and magnetic fields (EMF) may have harmful health effects. To address this concern, IAP Research has reviewed the relevant standards and related them to the pulsed fields produced by IAP’s equipment.

The Safety Standards

There are three organizations that publish safety standards for exposure to electromagnetic fields.

• ICNIRP, the International Commission on Non-Ionizing Radiation Protection. ²
• ACGIH, American Conference of Governmental Industrial Hygienists. They publish the "Threshold Limit Values and Biological Exposure Indices" annually. ⁸
• IEEE Standards Coordinating Committee 28 for Non-Ionizing Radiation Hazards. Their IEEE Standard C95.1-1991 gives recommendations to prevent harmful effects in humans exposed to electromagnetic fields in the frequency range from 3kHz to 300GHz.¹

There are no United States federal government regulations for exposure to electromagnetic fields in the relevant frequency range, which is around 3.5kHz. Likewise, ICNIRP and ACGIH give no guidelines for exposure to pulsed electromagnetic fields in the 3.5kHz frequency range.

For people with pacemakers, we are not aware of any safety standards that relate to the 3.5kHz pulsed fields produced by Magnepress^® equipment.

The IEEE standard applies to electromagnetic fields with frequencies from 3kHz to 300GHz. The fields produced by IAP’s metal forming and compaction coils are pulsed fields (1 cycle per discharge of the capacitor bank) operating in the very low end of the relevant spectrum, at about 3.5 kHz. Although the standard deals primarily with continuous fields, it does provide guidance for treatment of pulsed fields. Those guidelines are used for this bulletin.

Figure 1 shows the IEEE’s Maximum Permissible Exposure (MPE)¹ level (a constant 163 A/m) compared to the decreasing exposure of a person standing at increasing distances from the center of an example metal-forming electromagnetic coil. This exposure level assumes that the coil is pulsed 2 times per minute. Figure 1 shows that at one meter distance, the exposure is less than one-tenth of the maximum permissable exposure.

Figure 1. EMI from an example metal forming coil.

Figure 2 shows the IEEE’s Maximum Permissible Exposure (MPE)¹ level (a constant 163 A/m) compared to the decreasing exposure of a person standing at increasing distances from the center of an example powder-compaction electromagnetic coil.   Figure 2 shows that at one meter distance, the exposure is less than one one-hundreth of the maximum permissable exposure.

 Figure 2. EMI from a particular powder compaction coil.

To keep well below the IEEE’s recommended exposure limit, operators of Magnepress^® equipment should stay at least one meter from the electromagnetic coil when the coil is being pulsed. When the coil is idle, the electromagnetic emissions of the system are no greater than normal industrial and residential electrical equipment.

References

1. IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300GHz, IEEE Standard C95.1-1991.

2. Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic, and Electromagnetic Fields (Up to 300 Ghz), Health Physics, Vol. 74, No. 4, April 1998, pgs 494-522.
3. No Adverse Health Effects from EMFs, Journal of Environmental Health, Volume 59, No. 7, March 1997, Pgs 27-28.
4. Pacemakers and EMF, EPRI Journal, Volume 22, No. 3, May/June 1997, pg 4.
5. The EMF Controversy: Are Electromagnetic Fields Dangerous to Your Health?, Materials Evaluation, September 1997, pgs 994-998.
6. The Effects of Electromagnetic Fields on Cardiac Pacemakers, IEEE Transactions on Broadcasting, Vol. 38, No. 2, June 1992, pgs 136-139.
7. Maximum Pulsed Electromagnetic Field Limits Based on Peripheral Nerve Stimulation: Application to IEEE/ANSI C95.1 Electromagnetic Field Standards, IEEE Transactions on Biomedical Engineering, Vol. 45, No. 1, January 1998, pgs 137-141.
8. 1998 TLVs and BEIs: Threshold Limit Values for Chemical Substances and Physical Agents, published by the American Conference of Governmental Industrial Hygienists, 1330 Kemper Meadow Drive, Cincinnati, Ohio. 45240. Phone: (513) 742-2020.