I have issued hundreds of hot work permits (any work producing sparks or flame) in industrial facilities. For grinding, requirements include removal of combustible materials, fire blankets, running water hose, fire extinguisher, continuous monitoring for flammable vapors (LEL meter), a separate person as fire watch, face shield, leather gloves and notification to the fire brigade.
Grinding in a confined space (another high hazard permit required) increases risk an additional level - add inhalation hazards, asphyxiation, entrapment. Would need forced ventilation and fresh air supplied respirator.
Our maintenance department would not even suggest grinding if the work could be done with a saw, which is not considered hot work.
Sure, industrial requirements can be considered extreme when working on your own equipment but the risks are extreme - fire, explosion, injury, fatality.