Vaping involves heating a liquid solution to create an aerosol, which is inhaled into the lungs. This aerosol is often incorrectly called “smoke,” but it is chemically distinct from traditional cigarette combustion products. While vaping is intended for respiratory absorption, users sometimes accidentally swallow a portion of the mist or concentrated e-liquid. Swallowing these components introduces unique health implications due to the digestive process. This analysis details the chemical components of vape aerosol and the systemic and localized health effects that occur when these substances are swallowed.
What Exactly Is Swallowed in Vape Aerosol?
The substance aerosolized by a vaping device is an e-liquid, which is primarily a mixture of four components: Propylene Glycol (PG), Vegetable Glycerin (VG), flavorings, and often nicotine. Propylene Glycol and Vegetable Glycerin serve as the base, or carrier solvents, making up the vast majority of the liquid volume. These two substances are humectants, meaning they attract and retain moisture, which helps create the visible mist that mimics traditional smoke.
The flavorings added to e-liquids are numerous, often using compounds generally recognized as safe (GRAS) for food use. However, the GRAS designation applies to ingestion, not to heating and inhalation, and the safety profile for swallowing heated flavor derivatives remains unclear. Nicotine, the psychoactive agent, can be present in highly concentrated forms, especially in the liquid before it is aerosolized. When vaping, the user typically swallows a small, diluted amount of this mixture.
Acute Dangers of Nicotine Ingestion
The most immediate and serious danger associated with swallowing vape aerosol or, more critically, concentrated e-liquid, is acute nicotine poisoning. Nicotine is rapidly absorbed into the bloodstream through the mucous membranes of the mouth and the lining of the digestive tract. The concentration of nicotine in some e-liquids is high enough that even a small amount, particularly for children, can be life-threatening.
Nicotine toxicity typically presents in a biphasic pattern, beginning with stimulation within minutes of exposure. Initial symptoms include nausea, vomiting, increased salivation, abdominal pain, and an elevated heart rate (tachycardia). Vomiting is a common response, occurring in over half of symptomatic individuals, serving as a natural defense mechanism.
As the poisoning progresses, typically one to four hours after significant exposure, effects shift to central nervous system depression. Severe cases can lead to a slow heart rate (bradycardia), low blood pressure, seizures, and respiratory failure. If concentrated liquid is swallowed, immediate medical attention is necessary, and contacting a poison control center is the required first step. Survival beyond the first four hours after a severe overdose indicates a favorable prognosis.
Localized Effects on the Gastrointestinal Tract
Beyond the systemic danger of nicotine, the other components of the e-liquid can cause localized irritation within the digestive system. Propylene Glycol and Vegetable Glycerin, though considered safe for food use, can irritate the mucosal lining of the mouth, throat, and esophagus. Swallowing a larger amount of aerosol or liquid can lead to symptoms like a burning sensation in the mouth and stomach.
High concentrations of PG and VG can exert a hyperosmotic effect within the intestines, drawing water into the digestive tract. This influx of water can result in abdominal cramping, bloating, and diarrhea. The body metabolizes PG and VG slowly through the liver. While these substances are generally non-toxic, consuming excessive quantities can overwhelm the body’s processing capacity.
Flavoring compounds in the e-liquid are another source of potential irritation to the stomach lining. While these flavorings are approved for food consumption, their effects on the gut when concentrated or heated are still being studied. Nicotine itself also contributes to digestive upset by relaxing the lower esophageal sphincter, which allows stomach acid to reflux into the esophagus, causing heartburn. Some individuals report an upset stomach, nausea, and heartburn after vaping, potentially linked to the irritation caused by these chemical components.