The sharp irritation felt on the tongue or throat after inhaling from a vape cartridge is a common, unpleasant experience. Users often describe this sensation as a “burnt hit” or chemical sting. This sudden, localized reaction signals an issue with the device’s operation or the liquid’s chemical composition. Understanding the precise cause helps prevent this uncomfortable sting and ensures a smoother experience.
Thermal and Mechanical Causes
The most frequent cause of a burning sensation is a physical issue related to the device’s operation and temperature control. This harsh feeling often results from a “dry hit,” which occurs when the heating coil overheats the cotton wick before it is fully saturated with e-liquid. The dry wick burns the cotton material itself instead of vaporizing the liquid, delivering acrid smoke. This happens if the oil level is low or if the user takes rapid, successive puffs, known as “chain vaping,” which prevents the wick from re-soaking.
Another mechanical issue is “spitback,” which feels like hot liquid droplets hitting the tongue or throat. Spitback occurs when e-liquid pools on the coil’s surface instead of being instantly vaporized. The liquid boils and pops, sending tiny, hot droplets through the mouthpiece. This is exacerbated by using power settings that are too low or by over-priming a new coil. Operating the device at excessive voltage or wattage also contributes, as it causes the coil to vaporize the liquid too quickly, scorching the wick.
Chemical Irritants and Concentration Issues
Beyond physical heat, the liquid’s composition can trigger a chemical irritation that mimics a burn. Propylene Glycol (PG), a main base solvent in e-liquids, is a known irritant for some individuals. PG is thinner than Vegetable Glycerin (VG) and delivers a sharper “throat hit.” Users sensitive to PG may experience a stinging sensation or cough even during normal usage.
High concentrations of nicotine, especially in salt nicotine formulations, can also cause significant harshness. Nicotine is a potent chemical that delivers an intense sensation, which can be misidentified as a thermal burn on sensitive tissues.
Thermal Degradation Products
The burning sensation may also stem from the formation of thermal degradation products (TDPs). These compounds are created when components like PG or flavorings break down at high temperatures. Heating PG and VG can generate trace amounts of toxic compounds like formaldehyde, acetaldehyde, and acrolein, which are known irritants. Aldehyde-based flavorings, such as benzaldehyde or cinnamaldehyde, are particularly reactive. They can combine with PG to form flavor aldehyde PG acetals, which activate irritant receptors in the airways, contributing to the harsh feeling.
Troubleshooting and Safety Measures
To prevent a burnt hit, ensure the wick material is fully saturated before using a new cartridge or coil, a process known as priming. After filling, allow five to ten minutes for the liquid to fully soak into the wick before inhaling. Regularly checking the oil level is also important, as the wick cannot draw liquid effectively when the supply is low.
If your device has adjustable settings, verify the wattage or voltage is within the manufacturer’s recommended range for the installed coil. If a sudden burn occurs, immediately lower the power setting by a few watts. If the burning persists despite adjusting the power, the coil may be permanently scorched and should be replaced.
A strong, persistent chemical taste or burning sensation that does not resolve after troubleshooting may indicate a defective or contaminated product. If the taste is acutely chemical, metallic, or unbearable, or if the cartridge is visibly leaking, stop using and discard it immediately. Avoiding chain vaping and allowing brief pauses between puffs helps keep the coil from overheating and prolongs the cartridge’s life.