USP Grade – What is it in Vaping?

Definition

USP Grade is a purity standard applied to the propylene glycol (PG) and vegetable glycerine (VG) used in e-liquids. The letters stand for United States Pharmacopeia, an official public-standards-setting authority. When Aussie vapers see “USP Grade” on a bottle, it means the ingredient has been tested and verified to meet pharmaceutical-level purity—99.5 % or higher—free from heavy metals, microbes or other contaminants. Using USP Grade VG/PG ensures cleaner flavour, smoother throat-hit and safer clouds, making it the benchmark for reputable VapeJuice“>vape juice manufacturers worldwide.

Technical Details

To earn the USP label, raw glycerine or propylene glycol must pass monograph tests for specific gravity, refractive index, water content (<0.5 %), residue on ignition (<0.01 %), chlorides, sulfates and heavy metals (<5 ppm lead). Batches are sampled under Good Manufacturing Practice (GMP) and re-tested every 24 months. Two common variations appear on vape labels: “USP Kosher” (same chemical standard plus religious certification) and “USP Food Grade” (identical purity but packaged for food use). While VG is thicker and sweeter, USP PG carries flavour better and provides the “Hit“>throat hit”; most 70/30 or 50/50 e-liquids blend both USP components to balance wicking and cloud production.

Usage & Tips

  • Check the certificate: Reliable Aussie vendors publish a Certificate of Analysis (CoA) showing lot number and USP compliance—if it’s missing, ask.
  • Storage: Keep USP VG/PG in airtight, UV-blocking bottles below 25 °C to prevent oxidation; amber glass is ideal.
  • DIY mixing: Always use clean syringes and gloves; even USP nicotine oxidises faster when exposed to air, turning juice peppery.
  • Avoid “tech grade” or “industrial” glycerine: It may contain diethylene glycol—toxic when vaped.
  • Coil life: Higher USP VG ratios (80 %+) are thicker; pair with sub-ohm coils >0.2 Ω and larger wicking ports to prevent dry hits.

History & Context

The USP monograph for glycerine dates to 1820, but vaping adopted the standard in 2008 when early DIY forums demanded medical-grade safety. Australia’s TGO 110 nicotine regulations now implicitly require USP-grade carriers, aligning local e-liquid quality with global pharmaceutical norms.

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