Residual solvents, as defined by the US Pharmacopeia, are organic volatile chemicals that are used to produce or are produced in the manufacture of drug substances, dietary ingredients or excipients and in the preparation of finished products, both pharmaceutical and dietary supplements. Often these chemicals are not completely removed by the manufacturing processes utilized to produce finish products. Thus some level of residual solvents may be present in both the ingredients and finished products.

Purity tests USP 467 Class 1 and Class 2 Residual solvents with Gas Chromotography Mass Spectrometry equipment.