A “burnt cart” is the distinct, acrid taste experienced when a vape cartridge is overheated, causing the thermal decomposition of the oil and the materials within the heating element. This unpleasant, harsh sensation indicates that the device is operating outside its intended vaporization parameters. Inhaling this burnt aerosol signifies the creation of potentially harmful byproducts, and experts strongly discourage continuing use. Doing so exposes the respiratory system to toxins not present during normal operation.
Why Cartridges Burn
A vape cartridge’s core function relies on a heating element, or coil, and a wick—often made of cotton or ceramic—to efficiently turn oil into an inhalable aerosol. A burnt taste occurs when the coil heats up faster than the wick can re-saturate with oil, causing the wick material itself to burn directly. This is commonly referred to as a “dry hit,” which results in the unpleasant, charred flavor.
One of the most frequent causes is “chain vaping,” or taking multiple puffs in rapid succession without allowing sufficient time for the viscous oil to fully soak the wick between uses. Using a device at a high voltage or wattage setting is another major contributor, as excessive power causes the coil temperature to spike too quickly for the oil to effectively vaporize. Furthermore, when the oil level drops below the wick’s intake ports, the wick begins to burn in the absence of liquid saturation, leading to the characteristic burnt taste.
Harmful Compounds Released by Overheating
Normal vaping produces an aerosol, but the extreme heat from a burnt coil triggers pyrolysis, which is the chemical decomposition of materials. Among the most concerning chemicals are formaldehyde and acetaldehyde, which are known respiratory irritants and potential carcinogens. These aldehydes are formed when common vape carrier agents, like propylene glycol (PG) or vegetable glycerin (VG), are heated past their thermal breakdown points.
Another highly toxic aldehyde produced during the thermal degradation of glycerin is acrolein, which is known to cause severe irritation to the respiratory tract. Studies have shown that the concentration of these aldehydes, including formaldehyde, can increase significantly, up to 20-fold, when the temperature exceeds normal operating levels. The extreme heat of a dry hit also poses a structural risk to the hardware itself.
When the heating element—often composed of alloys containing metals like nickel, chromium, or copper—is subjected to excessive heat, it can degrade and release microscopic particles. This process, known as heavy metal leaching, introduces elements directly into the vapor stream that can be inhaled deep into the lungs. The high voltage and temperature settings associated with burning significantly enhance this release of contaminants like copper, nickel, chromium, and sometimes lead.
Acute Respiratory Effects
Inhaling the aerosol from a burnt cartridge immediately exposes the lungs to a mixture of toxic aldehydes and fine metal particulates, triggering an acute biological response. The high concentration of aldehydes, particularly acrolein, causes an immediate, severe burning sensation in the throat and mouth, often resulting in coughing and discomfort.
The inhalation of these toxins causes acute inflammation in the airways and lungs, damaging the delicate epithelial cells that line the respiratory tract. Continued exposure to these irritating compounds can lead to symptoms like wheezing, chest pain, and shortness of breath.
A more severe, though less common, risk associated with inhaling degraded oils and excessive particulate matter is chemical pneumonitis. This condition involves severe inflammation of the lung tissue caused by inhaling foreign substances. The burnt material, which includes carbonized wick remnants and degraded oil, acts as a pulmonary irritant that can lead to significant lung injury.
Steps to Avoid Burning Cartridges
Preventing a burnt hit is the most effective way to eliminate exposure to these harmful thermal degradation products.
- Verify that the battery is set to the lowest recommended voltage for the specific cartridge, as excessive power is the easiest way to overheat the coil. Many cartridges function optimally at or below 3.0 volts.
- Practice proper pacing and avoid taking long, continuous draws. Allowing a few seconds between puffs permits the thick oil enough time to fully re-saturate the wick.
- Proactively monitor the oil level and discard or refill the cartridge before the oil drops below the wick’s intake holes.
- When using a new cartridge, ensure the wick is fully saturated, or “primed,” by allowing the oil to soak for several minutes before the first use.