Benzotriazole sodium salt

Benzotriazole sodium salt (CAS 15217-42-2, EC 239-269-6) is the water-soluble sodium form of benzotriazole, commonly supplied under trade names including COBRATEC 40 S, Wintrol B 40NA, and ChemWorld 506. It carries no assigned E-code and is also referenced by the abbreviation NaBTA in technical literature.

In water treatment and metalworking fluids, NaBTA forms a stable, chemisorbed complex on copper and copper-alloy surfaces, blocking oxidative attack without interfering with system pH. In automotive coolants and industrial lubricants, it functions as a metal deactivator, coordinating with copper ions to prevent catalytic degradation of the base fluid.

Benzotriazole sodium salt is supplied as an aqueous solution, typically at 40% active concentration, and is registered under REACH. Procurement teams should confirm supplier Safety Data Sheets for classification under CLP Regulation and verify lot-specific documentation for quality-sensitive applications in electronics or closed-loop cooling systems.