Used in fertilizer production to provide phosphorus, an essential nutrient for plant growth. Commonly applied in the treatment of metal surfaces to remove rust and prepare them for painting or coating. Employed in the food industry as an acidulant in soft drinks and processed foods to enhance flavor and control pH. Utilized in dentistry and orthodontics to etch tooth surfaces for better adhesion of fillings and braces. Also serves as a buffering agent in pharmaceuticals and cleaning products.