電子菸，亦稱電子霧化器，其依液體溶液之成分，可分為含尼古丁成分或不含尼古丁成分之類型。依現行菸害防制法規定，電子菸非屬菸害防制法規範下之菸品，僅於特定情形下，受藥事法、菸酒管理法之管制。然2016年12月8日之菸害防制法修正草案版本中，新增電子菸之定義，依該修正條文，無論是否含有尼古丁成分，均屬菸害防制法管制之範圍，另修正草案條文亦明文規定任何人不得供應予未滿18歲者、不得製造、輸入、販賣或展示電子菸，此修正草案條文顯係對電子菸採取全面嚴格管制之立場。然而就單純之霧化、煙液器及加熱之電子裝置，以及未含尼古丁成分者而言，其對健康造成之危害尚無明確定論，故此菸害防制法修正草案版本之修正，已涉及規範正當性，以及是否違反比例原則之疑慮。此外，修正草案條文界定電子菸之方式亦過於寬泛，有執行上之困難，宜限縮於「具有有害物質之液體」加以管制。

E-cigarettes, also known as e-cigs, can be divided into two categories depend on whether or not its liquid contains nicotine. According to the current Tobacco Hazards Prevention Act, E-cigarettes are not regarded as tobacco products, thus, it just confined by Pharmaceutical Affairs Act or The Tobacco and Alcohol Administration Act in certain circumstances. However, Draft Revision of the Tobacco Hazards Prevention Act in December 8, 2016 added the definition of E-cigarettes. According to this draft revision, whether or not nicotine is contained, E-cigarettes should be governed by Tobacco Hazards Prevention Act. Pursuant to the draft revision, no person shall provide E-cigarettes to persons under the age of eighteen or manufacture, import, sell or display E-cigarettes. It is obvious that the draft revision confines E-cigarettes comprehensively and strictly. Nonetheless, the health risk of E-cigarettes which does not contain nicotine cannot be proved yet. Therefore, the draft revision of the Tobacco Hazards Prevention Act involves the regulatory legitimacy and the principle of proportionality. Moreover, the way of defining E-cigarettes under this draft revision is too broad to implement; thus, it should be limited to what contains hazardous substance.