In this chapter, the following terms have the meanings indicated. Terms Defined. “Batch type hot-dip galvanizing installation” means an installation in which clean, oxide-free iron or steel items are coated on a non-continuous basis with a thin layer of zinc by immersion in a bath of molten zinc. “Flux” means any chemical substance used in a hot-dip galvanizing installation to help metals fuse together by preventing oxidation.