This napthoic acid derivative, also known as 1,4-dihydroxy-2-naphthalenecarboxylic acid, presents as a pale yellowish gray to yellowish gray crystalline powder. Store in a cool and dark place at ambient temperatures. 1,4-Dihydroxy-2-naphthoic Acid is known to be incompatible with oxidizing agents and should not be stored or handled in their vicinity.