The American Conference of Governmental Industrial Hygienists
ACGIH publish TLVs (Threshold Limit Values) and BEIs (Biological Exposure Indices) to a whole range of chemical substances and physical agents, including EMFs.
TheTLVs and BEIs are published each year. usually, they do not change from one year to the next, so although they may be labelled with the current year, that does not imply they were published for the first time in that year.
The relevant TLVs (correct in 2015) are as follows:
Static magnetic fields
- Whole body (general workplace): 2 T
- Whole body (special worker training and controlled worl-place environment): 8 T
- Medical device wearers: 0.5 mT
Power frequency magnetic fields:
- Whole-body exposure
- 50 Hz: 1.2 mT
- 60 Hz: 1 mT
- Arms and legs
- 50 Hz: 6 mT
- 60 Hz: 5 mT
- Hands and feet
- 50 Hz: 12 mT
- 60 Hz: 10 mT
- 25 kV/m (applies equally to DC, 50 Hz and 60 Hz)
- Explanatory text recommends steps to address spark discharges and contact currents above 5 to 7 kV/m. Protective devices (e.g. suits, gloves and insulation) are suggested above 15 kV/m.