Propylene Glycol

PG stands for Propylene Glycol, a petroleum by-product. The fluid has no odor or color and is less dense than VG. Some users claim that Vaping provides a ‘throat hit’ similar to the sensation experienced when smoking tobacco. It also carries flavor more effectively than VG, making it the most commonly used suspension fluid for taste concentrates and nicotine.

Is it safe?

Studies have shown that PG is safe to ingest orally, and the FDA has deemed it “generally recognized as safe” to be used as a food additive. However, most studies into the safety of propylene glycol look at ingestion, rather than consuming it in aerosol form. Of the limited studies that exist, a long-term experiment held in 1947 judged that inhaling PG was ‘completely harmless’.

Vegetable Glycerin

VG stands for Vegetable Glycerin. It is a natural chemical derived from vegetable oils and safe for vegetarians. It is commonly used in e-liquid to give the vapor a ‘thick’ sensation. VG has a slightly sweet taste and is considerably thicker than PG. Vegetable Glycerin provides a much smoother throat hit than Propylene Glycol, making it more suitable for sub-ohm vaping. While nicotine and flavorings are suspended in PG, some vendors offer a VG alternative to enable 100% VG mixes.

Is it safe?

The FDA has classified VG as “generally recognized as safe,” It is widely regarded as one of the most benign substances known to man. The SIDS assessment profile shows it has low toxicity when consumed and low potential to irritate the skin or eye. This, along with the widespread use of VG in food and medicine, suggests it is safe for humans. However, as with PG, there are limited studies on inhaled VG instead of ingestion.

Conclusions:

• PG and VG are odorless liquids combined with flavor and nicotine to create e-juice.
• Both PG and VG technically belong to the alcohol chemical class (despite the name, they are not intoxicating). They are classified as sugar alcohols and are included in many consumable products.
• They produce vapor when heated, which allows them to be inhaled.
• PG and VG are not oils and can’t cause any medical issues — like lipoid pneumonia — that inhaling essential oils can.
• The two fluids have a different consistency and a slightly different taste.
• They have distinct mouth and throat sensations when vaped.
• Most modern e-liquid combines the two fluids, though the ratio can vary dramatically.

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