Volatile organic compounds (VOCs) include toluene and meta xylene. In the study of Czogala, J. et al. almost all of the detected smokes contained toluene . In the study of Goniewicz, M.L. et al. toluene and meta xylene were detected in almost all sample smokes. These VOCs are irritating to the skin and mucous membrane, and have an anesthetic effects on the central nervous system, as well as having certain carcinogenicity .