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IRLG Radio Frequency/Microwave Committee: Interim Statement on RF Sealers

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William A. Herman, Zorach R. Glaser · 1979

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Government agencies recognized RF sealer health risks in 1979, establishing early precedent for regulating high-power RF workplace exposures.

Plain English Summary

Summary written for general audiences

The Interagency Regulatory Liaison Group (IRLG) issued an interim statement in 1979 addressing occupational RF exposure from industrial RF sealers operating at 27 MHz and 2450 MHz frequencies. This government report examined workplace safety concerns for workers operating these high-power RF devices used in manufacturing to heat and seal materials. The document represents early regulatory recognition of potential health risks from occupational RF exposure in industrial settings.

Why This Matters

This 1979 government report marks a critical moment when federal agencies first acknowledged serious concerns about RF exposure in workplace settings. RF sealers represent some of the most intense RF exposures workers can face - these industrial machines generate power levels thousands of times higher than your cell phone to heat and bond materials. The fact that multiple government agencies collaborated on this interim statement shows they recognized the urgency of addressing these exposures, even without complete scientific certainty.

What makes this particularly relevant today is how it demonstrates the long history of RF health concerns in occupational settings. While your daily RF exposures from phones and WiFi are much lower than industrial RF sealers, the biological mechanisms of concern remain the same. This early regulatory attention to workplace RF safety helped establish exposure limits that continue to influence modern safety standards, though critics argue these limits remain inadequate for protecting public health from chronic, lower-level exposures.

Finding

In the view of the IRLG Radio Frequency/Microwave Committee, workers exposed to RF fields equivalent to plane-wave, far field exposures of 30 mW/cm² (10 mW/cm² in the literature quoted throughout this report) at 27 MHz have an increased risk to their health and safety.

In their words

In the view of the IRLG Radio Frequency/Microwave Committee, workers exposed to RF fields equivalent to plane-wave, far field exposures of 30 mW/cm² (10 mW/cm² in the literature quoted throughout this report) at 27 MHz have an increased risk to their health and safety.

Exposure Information

A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 10 to 60 MHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 10 to 60 MHzPower lines50/60 HzCell phones~1 GHzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Specific exposure levels were not quantified in this study.

Study Details

To address potential exposure of workers to fields emanating from RF sealers and identify a provisional level of human exposure that constitutes clear cause for concern.

Measurements of fields generated by RF sealers have shown levels in excess of 2000 V/m and 10 A/m. S...

Workers exposed to RF fields equivalent to plane-wave, far field exposures of 30 mW/cm² at 27 MHz have an increased risk to their health and safety. The statement is provisional and may be modified in the future as more information becomes available. The existing bioeffects data base is incomplete, but regulatory agencies must act with responsible conservatism in safeguarding public health.

Cite This Study
William A. Herman, Zorach R. Glaser (1979). IRLG Radio Frequency/Microwave Committee: Interim Statement on RF Sealers.
Show BibTeX
@article{irlg_radio_frequency_microwave_committee_interim_statement_on_rf_sealers_g7409,
  author = {William A. Herman and Zorach R. Glaser},
  title = {IRLG Radio Frequency/Microwave Committee: Interim Statement on RF Sealers},
  year = {1979},
  
  
}
No DOI on file for this study.

Quick Questions About This Study

RF sealers are industrial machines that use high-power radio frequency energy at 27 MHz or 2450 MHz to generate heat for welding, sealing, or bonding materials like plastics, fabrics, and wood products in manufacturing processes.
The Interagency Regulatory Liaison Group recognized that workers operating RF sealers faced potentially harmful RF exposures from these high-power industrial devices, prompting coordinated federal attention to workplace safety standards and regulations.
Both frequencies can cause tissue heating through energy absorption, but 2450 MHz (same as microwave ovens) penetrates less deeply while 27 MHz penetrates deeper into body tissues, creating different exposure patterns for workers.
RF sealers generate extremely high power levels during operation, creating intense electromagnetic fields that can cause tissue heating and other biological effects in workers positioned near these industrial machines during regular use.
This early government recognition of occupational RF risks established precedents for EMF safety regulations and demonstrated that federal agencies have long acknowledged potential health effects from electromagnetic field exposures.