E-liquid, often called vape juice, is a solution manufactured for use in electronic nicotine delivery systems (ENDS) like e-cigarettes. The device heats this liquid, converting it into an inhalable aerosol, commonly called vapor. This process, known as vaping, is fundamentally different from smoking, which involves combustion. E-liquid is formulated for vaporization and is not designed to be burned or subjected to high temperatures. The chemical reactions involved in each process are distinct and carry different risks.
Understanding Aerosolization Versus Combustion
Vaping operates on the principle of aerosolization. The e-liquid is heated by a coil to a controlled temperature, typically between 200 and 450 degrees Fahrenheit. This controlled heating allows the liquid to turn into an aerosol, which is a suspension of tiny liquid droplets in the air, without igniting the material. The resulting aerosol is chemically less complex than smoke, containing fewer compounds and no solid particles like ash or soot. This is a thermal process intended to avoid the chemical breakdown that occurs at higher temperatures.
In contrast, smoking involves combustion, the burning of material at much higher temperatures, often exceeding 900 degrees Fahrenheit. Combustion generates smoke, which is a complex mixture containing thousands of chemicals, including solid particulate matter and carbon monoxide. The physical difference between these two mechanisms is why attempting to burn e-liquid directly is a hazardous undertaking. E-liquid is not tobacco, and its components react very differently when subjected to a direct flame or excessive heat.
The Core Ingredients of E-Liquid
E-liquid is primarily composed of four main ingredients that serve as the base for vaporization. The majority of the liquid, often 95% or more, consists of a mixture of Propylene Glycol (PG) and Vegetable Glycerin (VG). These two compounds are humectants that attract and retain moisture, and they are responsible for creating the visible aerosol cloud.
Propylene Glycol is a thinner liquid that functions as a flavor carrier and contributes to the sensation known as a “throat hit.” Vegetable Glycerin, a thicker substance, is responsible for the density and volume of the aerosol produced. The remaining portion includes flavorings, often food-grade, and nicotine, which may be present in varying concentrations or absent entirely.
Chemical Risks of Burning Vape Juice Directly
When e-liquid is subjected to temperatures far exceeding the normal vaporization range, such as those created by an attempt to burn the liquid directly, it undergoes a destructive chemical change known as thermal decomposition. The primary risk is the breakdown of the PG and VG base into highly toxic compounds. This decomposition is specific to the burning process and is not a consequence of normal vaping.
Toxic Byproducts
When Vegetable Glycerin is overheated, it can break down to form acrolein, a severe irritant that can damage the lungs and is a known carcinogen. Similarly, excessive heat exposure causes Propylene Glycol to degrade, leading to the formation of volatile carbonyls, including formaldehyde and acetaldehyde. Formaldehyde and acetaldehyde are classified as human carcinogens and contribute to the health risks associated with traditional smoke. These dangerous byproducts only form in significant amounts when the e-liquid is combusted or exposed to extreme heat.
Hazards of Accidental Ingestion and Skin Contact
E-liquid presents significant hazards through accidental ingestion or prolonged skin contact, primarily due to concentrated nicotine. Nicotine is an acute toxin, and concentrated liquid forms are absorbed rapidly through the gastrointestinal tract or the skin. A very small amount of concentrated nicotine can be fatal, especially to children due to their lower body weight.
Accidental ingestion leads to systemic nicotine poisoning, with symptoms typically beginning within 15 to 60 minutes.
Symptoms of Nicotine Poisoning
- Burning in the mouth and throat.
- Nausea and vomiting.
- Dizziness and increased heart rate.
- Seizures, respiratory depression, and cardiac arrest (in severe cases).
To prevent these serious hazards, e-liquids, especially those with high nicotine concentrations, must be stored securely in child-resistant containers and kept out of reach of children and pets.