See under electronic cigarettes, e-cigarettes, ENDS. In addition to risks of vaping (can cause ARDS, somtimes fatal) and unknown adverse effects of agents including flavoring agent diacetyl and THC (PMID 25383564, 31491072), there is the risk of nicotine poisoning if cartridge contents is swallowed, notably by children. Cartridges may also contain illicit substances or drugs including cannabis (PMID 26347431), ‘sexual enhancers’ such as tadalafil, poppers (amyl nitrite, butyl nitrite), or drugs of abuse (PMID 30245461, 30835796).). Taking history of exposure to tobacco smoke, inhalants, stimulants, inhaled drugs and/or substances of abuse is indicated in every patient. Patients on oxygen (dioxygen) who use e-cigarette may suffer burns. See PMID 24338077, 24350225, 24575993, 24732161, 25383564, 27705269, 28522559, 31491070, 31491071, 31491072, 31491073)