Probably not SAFETY certified though -— and he will be responsible when the bins go up because a fan and a sensor fail simultaneously, causing a methane buildup, and then the “smart switches” finally get tripped in a methane/oxygen environment, and his family or workers are killed.
I post this as I sit in a PLC/SAFETY/ISO-26262 meeting.
Toyota paid 4 billion dollars for their bitflip error that caused Lexii to accelerate unbound.
Sometimes it is AOK to be cheap, other times, not so much.
Whether he used a PLC or PLA unless it is programmed tested and approved by various agencies $$$ and unless the wiring is good for Class 1 Div 2 or whatever is required...
Intrinsicly safe? A very specialized line of work.