... 2). Kojic acid, (5-hydroxy-2-hydroxymethyl-1,4-pyrone, CAS: 501-30-4) is whiteor off-white crystal, 3). Kojic acid, (5-hydroxy-2-hydroxymethyl-1,4 ... for cosmetics: 0.2~1.0%.(2) Raw Materials: Kojic acid, (5-hydroxy-2-hydroxymethyl-1,4-pyrone, CAS: 501-30-4) is the ... headache and toothache, etc.).(4) Agriculture: Kojic acid, (5-hydroxy-2-hydroxymethyl-1,4-pyrone, CAS: 501-30-4) is used in producing ...