Native Australian medicinal oil obtained from the leaves and terminal branchlets of the tea tree, Melaleuca alternifolia Myrtaceae. A complex mixture of hydrocarbons and terpenes of ≈100 components; the two standardized components for commercial use are 1,6-cineole (max of 15%) and the 1-terpinen-4-ol (min of 30%). Description: A. R. Penfold, J. Proc. R. Soc. N.S.W. 59, 306 (1925). Analysis and composition: J. J. Brophy et al., J. Agric. Food Chem. 37, 1330 (1989). Toxicity study: D. Villar et al., Vet. Hum. Toxicol. 36, 139 (1994). Antimicrobial activity: C. F. Carson, T. V. Riley, J. Appl. Bacteriol. 78, 264 (1995); and mode of action: S. D. Cox et al., ibid. 88, 170 (2000). Antifungal activity: K. A. Hammer et al., Antimicrob. Agents Chemother. 44, 467 (2000). Clinical evaluation in oral candidiasis in AIDS patients: A. Jandourek et al., AIDS 12, 1033 (1998). Review of early work: A. R. Penfold, F. R. Morrison, “Tea Tree Oils” in The Essential Oils 4, E. Guenther, Ed. (Van Nostrand Co., New York, 1950) pp 526-548. Review: J. A. Staton, Proc. 3rd. Sci. Conf. Asian Soc. Cosmet. Sci. Taipei, 18-24 (1997). Review of clinical trials: E. Ernst, A. Huntley, Forsch. Komplementrmed. 7, 17-20 (2000); of antimicrobial properties: L. Halcón, K. Milkus, Am. J. Infect. Control 32, 402-408 (2004); and medicinal properties: C. F. Carson et al., Clin. Microbiol. Rev. 19, 50-62 (2006). Review of toxicity: K. A. Hammer et al., Food Chem. Toxicol. 44, 616-625 (2006).