Like any transmitting antenna, magnetic loop or MagLoop also known as STL or small transmitting loop antennas transmit RF. So relative distance from antenna to operator, exposure over time, amount of radiated power, and antenna nulls or directivity should be considered while using any antenna. Many references for RF exposure distances and limits for magnetic loop antennas have already been written. Most of which recommend a 100W Loop be placed (about 10-13 feet) 3 to 4 meters or greater distance from the operator while operating. That distance will decrease at lower power levels (50W 5-6.5 feet, etc.). Here are a few references to guide your decisions:
http://www.nonstopsystems.com/radio/frank_radio_antenna_magloop.htm
https://www.hamradioandvision.com/small-loop-compliance-distance
http://transition.fcc.gov/bureaus/oet/info/documents/bulletins/oet65/oet65b.pdf (Table 17)
http://www.qsl.net/pg4i/3.html
The minimum coax length Alpha Antenna offers is 15 feet. This is because the safest distance between the antenna and operator is 10-13 feet or greater. For more information, CLICK HERE for a list of available 100W Magnetic Loop Antennas