Homophthalic Acid Stellar 2001 seems to refer to a specific product or grade of homophthalic acid that is marketed under the Stellar 2001 brand name. Unfortunately, there is limited detailed public information about a specific product called "Stellar 2001" tied directly to homophthalic acid. https://www.sarex.com/fine/product/key-products/homophthalic-acid-stellar-2001