Battery explosions are caused by an increase in internal battery temperature and some have resulted in severe skin burns. There is a small risk of battery explosion in devices modified to increase battery power. Nicotine poisoning related to e-cigarettes include ingestion, inhalation, or absorption via the skin or eyes. Accidental poisoning can result from using undiluted concentrated nicotine when mistakenly used as prepared e-liquid. There is possibility that inhalation, ingestion, or skin contact can expose people to high levels of nicotine. Concerns with exposure to the e-liquids include leaks or spills and contact with contaminants in the e-liquid. Pregnant women, breastfeeding mothers, and the elderly are more sensitive to nicotine than other individuals. There are<unk>  issues with the nicotine exposure from e-cigarette use, which may cause addiction and other adverse effects. There is considerable variation among e-cigarettes and in their liquid ingredients. and thus the contents of the aerosol delivered to the user. The cytotoxicity of e-liquids varies, and contamination with various chemicals have been detected in the liquid. E-cigarette vapor potentially contains harmful chemicals which are not found in tobacco smoke. Studies over a year on the effects of exposure to e-cigarettes have not been conducted, as of 2019. The risk from serious adverse events, including death, was reported in 2016 to be low. The long-term health consequences from vaping is likely greater than nicotine replacement products. They may produce fewer adverse effects compared to tobacco products. They may cause long-term and short-term adverse effects, including airway resistance, irritation of the airways, eyes redness, and dry throat. Short-term adverse effects reported most often were mouth and throat irritation, dry cough, and nausea. Adverse effects are mostly associated with short-term use and the reported adverse effects decreased over time. Dryness of the mouth and throat is believed to stem from the ability of both propylene glycol and glycerin to absorb water. Some e-cigarettes users experience adverse effects like throat irritation which could be the result of exposure to nicotine, nicotine solvents, or toxicants in the aerosol. Vaping may harm neurons and trigger tremors and spasms. The use of e-cigarettes has been found associated with nose bleeding, change in bronchial gene expression, release of cytokines and proinflammatory mediators, and increase in allergic airway inflammation which can exacerbate asthmatic symptoms, thus elevating infiltration of inflammatory cells including eosinophils into airways. A 2016 study found vaping using an e-liquid containing 23% alcohol was linked to reduced performance on the Purdue Pegboard Test. Reports to the FDA in 2013 for minor adverse effects identified with using e-cigarettes included headache, chest pain, nausea, and cough. Major adverse events reported to the FDA in 2013 included hospitalizations for pneumonia, congestive heart failure, seizure, rapid heart rate, and burns. However, no direct relationship has been proven between these events and e-cigarette use, and some may be due to existing health problems. Many of the observed negative effects from e-cigarette use concerning the nervous system and the sensory system are possibly related to nicotine overdose or withdrawal. Battery-related malfunctions Most e-cigarettes use lithium batteries, the improper use of which may result in accidents. Most fires caused by vaporing devices are a result of the lithium batteries becoming too hot and igniting. Defective e-cigarette batteries have been known to cause fires and explosions. The chance of an e-cigarette blast resulting in burns and projectile harms greatly rises when using low-quality batteries, if stored incorrectly or was altered by the user. Inexpensive manufacturing with poor quality control could account for some of the explosions. It has been recommended that manufacturing quality standards be imposed in order to prevent such accidents. Better product design and standards could probably reduce some of the risks. It is recommended that users be informed of appropriate charging and storage methods. In the event the lithium ion substances leak from the battery as a result of an e-cigarette blast, first aid is recommended to prevent additional chemical reaction. An e-cigarette blast can induce serious burns and harms that need thorough and lengthy medical treatment particularly when a device goes off in hands, mouths, or pockets. A 2017 review found "The electrolyte liquid within the lithium ion battery cells is at risk for overheating, thus building pressure that may exceed the capacity of the battery casing. This "thermal runway" can ultimately result in cell rupture or combustion." Metal objects, including coins or keys, can cause a short circuit when kept with batteries, which can result in overheating of the battery. It is recommended to use insulated protective cases for batteries not in use to lessen the potential risk related to thermal runaway. Swallowing e-cigarette batteries can be toxic. Graphic from an October 2014 alt=Graphic from an October 2014 United States Fire Administration (USFA) report entitled Electronic Cigarette Fires and Explosions. The USFA said that 25 fires and explosions in the US were the result of e-cigarette use between 2009 and August 2014. The numbers of medical reports from harms resulting from vaping have continued to increase since 2016. Some batteries are not well designed, are made with poor quality components, or have defects. Major injuries have occurred from battery explosions and fires. Fires caused by e-cigarettes appear to be increasingly frequent. Direct harms from an e-cigarette blast include hand harms, face harms, waist/groin harms, and inhalation harms. Indirect harms happened when the vaporing device set on fire another object and resulted in a house fire, followed by harm from fire burns or inhalation. E-cigarette explosions have resulted in burns, lost teeth, neck fractures, and battery acid contact to the face, mouth, and eyes. The extent of the burns varied from 1% to 8% total body surface area, were reported and most commonly occurred in the lower extremity, hands, head and neck, and genitalia. The extent of the burn was mainly deep partial and full thickness. E-cigarette explosion harms correlated with malfunctioning of the device can result in minor total body surface area 2nd and 3rd degree burns. Around 50% needed surgical management for the burn. This was due to the extent of the injury. The most common harms are burns as a result of explosion in the pocket and harms to the face. A 2017 review found "Several of the reported cases show that 'the battery in pocket' precedes the incident. The damp environment in the pocket may have sufficient moisture to start a chemical reaction within the lithium-ion battery and the presence of metal objects can produce short-circuit which can over heat the battery leading to an explosion." Flame burns, chemical burns, and blast injuries have occurred as a result of the e-cigarette battery overheating. A man endured a unilateral corneoscleral laceration with prolapsed iris tissue and hyphemato to the eye area when an e-cigarette exploded in his mouth. A young man endured bilateral corneal burns to the eye area when an e-cigarette exploded near his chest. A man lost his life when his charging e-cigarette blew up and caught on fire next to oxygen equipment. House and car fires and skin burns have resulted from some of the explosions. The explosions were the result of extended charging, use of unsuitable chargers, or design flaws. There is a possible risk to bystanders from e-cigarette explosions. There is also a risk of property damage as a result of flammable materials catching on fire from an e-cigarette explosion. A March 2016 research article assembled reports by US government agencies and in the media of 92 e-cigarette blasts, fire, or overheating events, with related injuries in 47 individuals. Prominent harms included 2 cervical vertebral fractures, 1 palate fracture, 3 instances of damaged teeth, 33 thermal burns, 4 chemical burns, and 5 lacerations. alt=Graphic from a July 2016 United States Fire Administration (USFA) report entitled Electronic Cigarette Fires and Explosions in the United States 2009 – 2016. There has been an increase in the number of severe and moderate injuries resulting from e-cigarette explosions and fires since 2014. The USFA noted that this appears to correlate well with the e-cigarette sales trend. Between January 2015 and May 2016, 35 burns and correlated injuries were caused by e-cigarette explosions. Between January 2009 and December 31, 2016, 195 separate incidents of explosion and fire involving an e-cigarette were reported by the US media. These incidents resulted in 133 acute injuries. Of these injuries, 38 (29 percent) were severe. Sixty-one incidents occurred when either the device or spare batteries for the device were in a pocket. Sixty incidents occurred while the device was being used. Forty-eight incidents occurred while the battery in the device was being charged. Eighteen incidents occurred while the device or battery was stored. In seven incidents, it is not reported whether the e-cigarette was in use, stored, or being charged. One incident occurred during transportation on a cargo aircraft. Media reports generally characterize these incidents as explosions. While there is generally a brief period of overheating and off-gassing at the onset of the event, the events tend to occur suddenly, and are accompanied by loud noise, a flash
Safety of electronic cigarettes
Positions of medical organizations on electronic cigarettes
Road traffic safety
Construction of electronic cigarettes
Electronic cigarette and e-cigarette liquid marketing
Bicycle safety
Personal health application
Modesty in medical settings