Przedsiębiorstwo Innowacyjno-Wdrożeniowe Delta has produced chemical specialities at Krupczyn near Dolsk in Wielkopolska since 1984, and its fire line is the EXPANDER-FR intumescent varnish for timber and wood-based boards. ITB’s national register lists Delta as holder of ITB-KOT-2018/0476, third edition, issued in October 2024 and valid to December 2028, covering EXPANDER-FR for protecting timber building elements and wood-based panels including chipboard, plywood and oriented strand board. The assessment is held in the manufacturer’s own name. Its other lines are vulcanising chemicals and biocidal protective agents, so fire protection is one product family rather than the whole business.