Caustic Soda is primarily available in Flakes, Pearls, and Liquid (Lye) forms. For most B2B buyers, Caustic Soda Flakes 99% and Pearls 99% are the industry standards due to their high purity and ease of storage. Flakes are generally more cost-effective for large-scale industrial dissolution, while Pearls offer better flowability and are easier to measure for automated processes. If your facility is equipped with storage tanks and requires immediate integration into aqueous processes, Liquid Caustic Soda (32% or 50% concentration) may reduce labor costs, though it incurs higher shipping costs due to the water weight.