I used to work for a company that bought off cuts from this plant and the static that comes off of these rolls is scary. I heard this story years ago and no one in our plant had a doubt about it being true because 3M ran enormous rolls.
See, I can believe that there are enormous EM fields in play. But I can't believe that the employees working there would react to them without code brown-ing.
When I was young I started my career working in manufacturing. Specifically machine shops with presses, CNC machines, EDM machines, ect...
You would be amazed at the level of hazard people are willing to accept. For example, I recall running one machine, a 300 ton press with an 84"x54" bed and 24" of stroke. It was 25 feet tall and we nicknamed this one Optimus Prime. When Optimus was warmed up he would spit warm hydraulic oil all over the place. A nice fine mist along with a slurry of hydraulic rain drops would cover the area. The solution was to wear Weimao hats made out of disposable cardboard.
Another machine was a 50+ year old roll form machine. How I did not lose my life on this machine is beyond me. Modern machines feed the material automatically and have clutches and brakes with optical sensors so they can stop on a dime. This one literally used inertia and a massive flywheel to function. You got the rollers spinning and fed the material into the first roller, then as it came out you had to guide the material into the next roller. Manually. In between spinning rollers. With your hands. And the machine had a 1,000lb flywheel that gave the whole thing intertia. You only needed to give it throttle once, and the whole machine would spin for 30+ seconds whether it was forming material, or your arm, or whatever. Chances are it would have sucked an entire human into the rollers on one blip of the throttle. And the coup de grâce was the throttle was a 50lb lever on a swing pivot. If you drop this lever to turn the machine OFF, it would bounce with gravity and bounce itself back on. This is not a third world country. These machines are located in Newburyport Massachusetts.
I was a lot younger back then, but to this day that is how helicopter engine are made. Those antiquated tools are more important to the major aerospace companies than any operator they've ever had.
I had the pleasure of operating some machines like that too. One was a hydraulic shear roughly the size of a school bus, and once you stomp the pedal there is absolutely no taking it back--it'll do a cycle and nothing can stop it. We also had a Buffalo Iron Worker which I managed to misalign a punch in once. A hefty chunk of HSS flew ~100ft across the shop and embedded itself in the steel siding. I don't know how it didn't hit me, because I was at the time occupying much of the solid angle. However the machine that scared me most was a giant drill press from the late 1800s that had a ~4' cast iron gear on top of the drill shaft which held enough inertia to keep the drill spinning for about a minute after the power was shut off.
Considering that it's possible to levitate a live frog with a (very strong) magnet without killing it, I'm able to believe that a sufficiently strong magnetic field can be detectable by a human without killing or immediately, obviously harming them.
