Boric Acid

Boric acid (H3BO3, CAS 10043-35-3) is a weak, temperature-stable acid supplied by Global Chemicals LLC from Muscat stock at 99.5% minimum purity, as white crystalline powder or flakes. It dissolves at 5.7 g per 100 mL of water at 25°C, more at higher temperature, and a 0.1 M solution reads about pH 5.1, a saturated one about pH 4.1. Because it is a very weak acid (pKa 9.24) it buffers over a wide range without attacking steel, which is what makes it useful downhole.

In oilfield fluids. Boric acid and borate salts are the boron source for borate-crosslinked fracturing fluids, where the crosslink forms as pH rises and breaks again as it falls, giving a fluid that carries proppant and then cleans up. In water-based drilling and completion fluids it acts as a pH buffer and as a mild corrosion inhibitor, and it stays effective at the bottom-hole temperatures that break down organic additives. It also inhibits bacterial growth in stored mud.

Other uses. Borosilicate glass and glazes, where boron lowers the melting point and thermal expansion; flame retardants for cellulose and timber; nuclear reactors, where the boron-10 isotope absorbs neutrons; and as the starting material for borax, boron esters and other boron compounds.

Handling. Boric acid has low acute toxicity but is classified as toxic to reproduction under GHS and CLP, so plants handle it with dust control, gloves and a particle mask, and keep it out of food and feed areas. It is non-flammable and stable in storage when kept dry; it loses water above 100°C to form metaboric acid.

What to specify when you order. Purity (technical 99.5% or higher), form (granular or powder), and pack: 25 kg bags, drums or bulk bags. A certificate of analysis accompanies each lot and the SDS is available on request. Muscat stock ships the same day in the capital area and next day to Sohar.