Boric Acid (H₃BO₃) is a white, water-soluble crystalline compound used in ceramics as a source of boron (B₂O₃) in glazes and frits. It begins to decompose around 150–300 °C, releasing water and forming boron oxide, which then acts as a flux to help melt silica at lower temperatures. Because of this behavior, boric acid is often used in low-fire and fast-fire glaze formulations to promote gloss and glass formation. (digitalfire.com) Boric Acid can irritate the respiratory system, eyes, and skin. Avoid inhaling the dust, and when mixing always wear gloves, a dust mask or respirator, and work in a well-ventilated area. Do not ingest, and wash hands and exposed skin thoroughly after handling.
