{"id":19538,"date":"2025-06-30T10:49:04","date_gmt":"2025-06-30T09:49:04","guid":{"rendered":"https:\/\/www.thevapeshop.co.uk\/blog\/?p=19538"},"modified":"2025-06-30T10:49:05","modified_gmt":"2025-06-30T09:49:05","slug":"understanding-the-types-of-propylene-glycol-in-e-liquid","status":"publish","type":"post","link":"https:\/\/www.thevapeshop.co.uk\/blog\/understanding-the-types-of-propylene-glycol-in-e-liquid\/","title":{"rendered":"Understanding the Types of Propylene Glycol in E-Liquid"},"content":{"rendered":"\n

If you\u2019ve ever looked closely at an e-liquid bottle, you\u2019ve probably noticed propylene glycol<\/em> listed as one of the main ingredients. Often shortened to PG, it\u2019s the quiet workhorse in your vape \u2014 delivering flavour, enhancing throat hit, and balancing the mix with vegetable glycerine. But here\u2019s where things get interesting: not all PG is the same<\/strong>, and when it comes to inhalation safety, the type used matters more than most vapers realise.<\/p>\n\n\n\n

At The Vape Shop, only USP and EP grade propylene glycol is used across all blends, including a natural e-liquid range<\/a>. This article examines the various types of propylene glycol used in vaping, their differences, and why pharmaceutical-grade PG is the only type that should ever reach your tank.<\/p>\n\n\n\n

What is Propylene Glycol in Vaping?<\/strong><\/h2>\n\n\n\n

Propylene glycol is a colourless, odourless liquid that\u2019s used in everything from food flavourings<\/a> to asthma inhalers<\/a>. In vaping, PG works as a carrier, helping flavours blend smoothly while giving a satisfying throat sensation. It\u2019s also thinner than VG, which makes it ideal for pod systems and flavour-forward mixes.<\/p>\n\n\n\n

But behind the simplicity of this ingredient lies a crucial distinction: the grade of propylene glycol can determine whether it\u2019s safe for inhalation, or more suited to antifreeze and paint thinners.<\/p>\n\n\n\n

Breaking Down the Types of Propylene Glycol<\/strong><\/h2>\n\n\n\n

There are four main types of PG you may come across, either in e-liquid manufacturing or on ingredient lists. Understanding the difference is crucial, especially for vapers who value quality and transparency.<\/p>\n\n\n\n

Table: Types of Propylene Glycol and Their Key Differences<\/strong><\/h3>\n\n\n\n
Type of PG<\/strong><\/td>Purity<\/strong><\/td>Intended Use<\/strong><\/td>Safe for Vaping<\/strong><\/td>Common Applications<\/strong><\/td><\/tr>
USP Grade PG<\/strong><\/td>\u226599.8%<\/td>Pharmaceutical, inhalation, food<\/td>\u2705 Yes<\/td>Inhalers, e-liquid, medical carriers<\/td><\/tr>
EP Grade PG<\/strong><\/td>\u226599.5%<\/td>Pharmaceutical (EU), inhalation<\/td>\u2705 Yes<\/td>E-liquid, medicine, personal care products<\/td><\/tr>
Food Grade PG<\/strong><\/td>\u226599.5%<\/td>Ingestion only<\/td>\u26a0\ufe0f Possibly<\/td>Flavourings, cosmetics<\/td><\/tr>
Industrial Grade PG<\/strong><\/td>95\u201399%<\/td>Technical and industrial use<\/td>\u274c No<\/td>Antifreeze, plastics, paint solvents<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Both USP (United States Pharmacopeia)<\/a> and EP (European Pharmacopoeia)<\/a> grades meet extremely strict standards for purity and safety. These are the only two types of PG truly suitable for inhalation through vaping.<\/p>\n\n\n\n

What Makes USP and EP Grade PG Safe?<\/strong><\/h2>\n\n\n\n

USP and EP grade PG is produced under pharmaceutical-level conditions. The manufacturing process involves multiple stages of purification, including fractional distillation and filtration, to ensure no harmful impurities are left behind. Final batches are tested against stringent purity criteria and monitored for residual solvents, microbial contaminants and heavy metals.<\/p>\n\n\n\n

Because of this, pharmaceutical-grade PG is used in products designed for the lungs, like medical nebulisers and inhalers, not just e-liquids.<\/p>\n\n\n\n

When vapers talk about clean flavour, smooth delivery and predictable performance, USP and EP grade PG is what makes that possible.<\/p>\n\n\n\n

Why The Vape Shop Uses Only USP\/EP Grade PG<\/strong><\/h2>\n\n\n\n
\"The<\/figure>\n\n\n\n

At The Vape Shop, we\u2019ve built our formulations on ingredient integrity<\/a>, especially in our natural e-liquid collection, which avoids artificial sweeteners and unnecessary additives. Our commitment to USP\/EP propylene glycol ensures that:<\/p>\n\n\n\n