EU Trademark Classification EU01 Chemicals Potassium ferrocyanide Class 01 Potassium ferrocyanide 4221 亚铁氰化钾 Chinese 亚铁氰化钾 English Potassium ferrocyanide Spanish ferrocianuro de potasio Site ref. 4221 Class 01 Included in Harmonised Database (HDB), TM5 ID List