"Process unit shutdown" means a work practice or operational procedure that stops production from a process unit or part of a process unit. An unscheduled work practice or operational procedure that stops production from a process unit or part of a process unit for less than 24 hours is not a process unit shutdown. The use of spare equipment and components and technically feasible bypassing of equipment and components without stopping production is not a process unit shutdown.
Ill. Admin. Code tit. 35, § 211.5230
Added at 17 Ill. Reg. 16504, effective September 27, 1993