Hydrofluoric Acid 50% Lab, 4L. $150.00. Qty: Add to Shopping Cart. Hydrofluoric Acid 50% Solution | 500ml, 1 & 4 Liter Bottle | Technical & Lab Grade | Formula HF | Highly Corrosive | Dangerous Inorganic Acid | For Industrial Uses, Glass & Enamel Etching, Cleaning Brass & Aluminum, Removing Rust |