4-Chloro-3,5-dimethylphenol (CAS 88-04-0), with molecular formula C?H?ClO and molecular weight 156.61 g/mol, features a chloro group at C4 and methyl groups at C3/C5 of the phenol ring. It is a widely used antimicrobial agent, effective against bacteria/fungi, applied in disinfectants, cosmetics, and industrial preservatives. It requires sealed, cool storage to avoid oxidation, maintaining its biocidal activity for practical use.