Residual Solvents in Botanical Extraction: USP <467> Class Limits and GC-HS Analysis
Technical breakdown of Gas Chromatography Headspace (GC-HS) analytical screening for organic residual solvents in botanical extracts according to USP <467> and European Pharmacopoeia 5.4 Class 1, 2, and 3 guidelines.
Author: Botanix Natural Quality EngineeringLast Verified: 2026-08-14
Classification of Solvent Safety Limits (USP <467>)
Solvents used in solid-liquid extraction are classified into 3 risk categories based on toxicity and environmental safety.
- Class 1 Solvents: Carcinogenic and toxic (e.g. Benzene, Carbon Tetrachloride) — STRICTLY PROHIBITED in food & supplement processing
- Class 2 Solvents: Limited concentration limits (e.g. Methanol ≤ 3000 ppm, Hexane ≤ 290 ppm)
- Class 3 Solvents: Low toxic potential (e.g. Ethanol, Ethyl Acetate, Isopropanol) — Permissible up to 5000 ppm (0.5%)
Referenced Botanix Standardized Ingredients
Technical Frequently Asked Questions
Why is ethanol the preferred extraction solvent for natural health products?
Ethanol is a Class 3 solvent with low toxicity, recognized as Generally Recognized As Safe (GRAS) for dietary ingredient processing, providing broad polyphenol solubility with safe residual limits.