There is only limited testing performed using NavVis devices in strong electromagnetic environments.
The NavVis VLX has passed in magnetic fields up to 30A/m (50/60 Hz stimulation), but a test against high electrical fields hasn't been done. The device is immune against RF fields 80 MHz-6 Ghz with up to 10V/m. NavVis advises against scanning in environments above these values.
Electric discharges as well as strong electric and magnetic fields pose a risk to the device itself but also to the operator. Examples of this type of environment include the following:
Power plants and substations
Electrolysis or electroplating plants
Electro-welding systems
Medical therapy and diagnosis systems (eg. MRI)
The device could suffer from temporary errors on site, but also permanent damage to the electrical components or sensors. For example, ESD events near the display can cause the screen to turn black, which will likely recover after a reboot.
For the operator we highly recommend checking the occupational health and safety regulations, which every worker must be educated on and complied with before entering such an environment.
However, if the device is used in such an environment it is at your own risk.