Somewhere 10 years ago a serious media and public debate took place on the potential hazard of power line electromagnetic fields. To help in resolving the controversial problem related to potential hazard of power line electromagnetic fields the Congress of the USA allocated 41 million US dollars for a 5-year RAPID program designed to investigate the potential of EMF to initiate cancer. After five years this program as well as several other independent panels concluded "there is no convincing evidence to affirm that magnetic fields from power lines are associated with cancer promotion".

Pay attention to the fact that WHO suggests that "precaution" principle will be applied toward biological and health effects caused by magnetic fields. Which means, "until proven safe, we should apply caution to magnetic field initiated bioeffects". In addition, the potential hazard occur when humans are continuously exposed to certain electromagnetic fields, while the therapeutic application requires several (normally 10-15 30-60 minute sessions) at fields that are hundreds times stronger than the surrounding electromagnetic fields. Remember: the fields are stronger but applied for short time in controlled conditions.

Nevertheless, every time one is suggested to use a physical therapy device, two questions arise: How much help I will receive? How safe is the device. Let try to answer the second question first.
It is a guiding principle that any attempt to utilize an electrically driven device, one has to address the device’s safety. Here is THERAMAG USA’s position:

The actual safety of THERAMAG is considered in the following directions:

The electrical safety of the device is assured by strict enforcement of the National Electric Code requirements.
THERAMAG is a device that generates magnetic fields in the range of up to 2,000 Gauss – this level is well within the limits of safety values of magnetic field strength as defined by the World Health Organization (which is 20,000 Gauss).
The patient safety is secured by following the criteria of World Health Organization (WHO) which indicated that magnetic fields used for diagnostic and therapy should not exceed 20,000 Gauss. From this point the magnetic fields generated by THERAMAG devices are 10-20 times smaller than the limit.
Safety of the operators of the device is achieved by such construction of the units at which at 3 feet from the THERAMAG magnetic field is at the background level.
THERAMAG is not a miracle device, nor a cure. It is a useful tool for your well-being.