This cyclooxygenase (COX) inhibitor, also known as Naproxen, presents as a white to very pale yellow and nearly odorless crystalline powder. It is known to be very soluble in alcohols and insoluble in water. Keep container tightly closed. Store in a cool and dark place at ambient temperatures - this substance is light sensitive. (S)-(+)-2-(6-Methoxy-2-naphthyl)propionic Acid is incompatible with oxidizing agents. This chemical is toxic if swallowed and causes skin irritation and serious eye irritation.