We have rewired parts of a fertilizer plant in all pvc and plastic enclosures.
Nema 12R discos that are less than 5 years old are hardly recognizable on the outside. Inside they are still like new. It's a really nasty environment.
They are slowly replacing all the conveyors and bucket elevators with stainless steel equipment.
Plastic may not offer much impact protection, but it's better than switches that won't operate due to corrosion.
