Propylene glycol vape

Propylene glycol (PG) is one of the two core base solvents in e-cigarette liquid, typically accounting for 80% to 94.9% of the total liquid volume. It, along with Vegetable Glycerin (VG, plant glycerin), forms the base of the e-cigarette liquid.

It plays several key roles in e-cigarettes:

Core role of propylene glycol (PG)
Flavor carrier and nicotine vehicle: PG is almost colorless and odorless, and is an ideal solvent for flavoring agents and nicotine, allowing various flavors to be evenly distributed in the e-cigarette liquid. At the same time, it can effectively promote the release of nicotine.

Providing "throat hit": When heated, PG brings a sensation similar to that of traditional cigarettes, also known as "throat hit" (Throat Hit). This is an experience that many users, especially those transitioning from traditional cigarettes, value.

Diluting VG and enhancing fluidity: VG is very viscous, while PG has good fluidity. Adding PG can reduce the overall viscosity of the e-cigarette liquid, ensuring that the liquid can be smoothly absorbed by the wick and avoiding the problem of dry burning and caking of the core due to poor oil supply.

⚖️ PG/VG ratio: Determining your vaping experience
The ratio of PG to VG directly determines the taste, smoke volume, and compatibility of the device of the e-cigarette liquid. Here are some common ratios:

Type PG : VG ratio Primary characteristics Applicable scenarios
High-PG e-liquid Approximately 60% PG / 40% VG or higher Strong throat hit, high flavor resolution, good e-liquid fluidity. Suitable for mouth-to-lung (MTL) devices and small cigarettes, seeking a similar cigarette experience.
Balanced e-liquid 50% PG / 50% VG Achieves a balance between throat hit, flavor, and smoke volume. Highly versatile, suitable for most devices.
High-VG e-liquid Approximately 30% PG / 70% VG or higher Enormous smoke volume, smoother and denser taste, but weaker throat hit. Suitable for lung-to-lung (DLT) large smoke devices, players seeking visual effects.
⚠️ Health risk warning: Products after heating
Although the US Food and Drug Administration (FDA) classifies PG as a "generally recognized as safe" (GRAS) food additive, this only applies to oral or skin contact and does not mean inhalation is safe.

Studies have clearly shown that when PG and VG are heated and vaporized by e-cigarettes, new risks are produced:

Pyrolysis products: High temperatures cause PG/VG pyrolysis, generating various toxic and harmful substances such as formaldehyde, acetaldehyde, and acrolein.

Health effects: These decomposition products may cause oxidative stress, respiratory inflammation, and may increase the risk of cancer. A study also pointed out that PG can damage the epithelial cells of the small airways of the human body.

In conclusion, propylene glycol (PG) is an indispensable solvent in e-cigarettes, determining the flavor delivery, throat hit, and fluidity of the e-cigarette liquid. However, it must be recognized that the chemical substances produced by heating PG and VG at high temperatures have potential health risks.