"Flush cleaning at aerospace facilities" means removal of contaminants, such as dirt, grease, oil, and coatings, from an aerospace vehicle or component or from coating equipment by passing solvent over, into, or through the item being cleaned. The solvent may simply be poured into the item being cleaned and then drained, or assisted by air or hydraulic pressure, or by pumping. Hand-wipe cleaning operations in which wiping, scrubbing, mopping, or other hand action are used are not included in this definition.
Ill. Admin. Code tit. 35, § 211.2412