FDA Compliant GFS Tanks: Food-Contact Enamel and 21 CFR 175.300 An FDA compliant GFS tank stores food-grade or potable liquid against a surface formulated for contact under 21 CFR 175.300. The compliance lives in the enamel frit and the coating certificate, not in the steel alone. Engineered by Shijiazhuang Zhengzhong Technology Co., Ltd. (Center Enamel), a Glass-Fused-to-Steel (GFS) tank can be produced with contact-grade enamel when the frit and the documentation are