"Freeboard height" means, for open top vapor degreasers, the distance from the top of the vapor zone to the top of the degreaser tank, and for cold cleaning degreasers, the distance from the solvent to the top of the degreaser tank.
Ill. Admin. Code tit. 35, § 211.2450
Added at 17 Ill. Reg. 16504, effective September 27, 1993