Hydrofluoric acid (HF) is a colorless, corrosive liquid that is a solution of hydrogen fluoride in water. It is known for its ability to dissolve glass and many metals, making it useful in various industrial applications, such as glass etching and metal cleaning. Due to its high reactivity, it must be handled with extreme caution. Despite being a weak acid compared to others, hydrofluoric acid can cause severe chemical burns and systemic toxicity if it comes into contact with skin or is inhaled. Safety measures, including protective gear and proper ventilation, are essential when working with this hazardous substance.