What are Residual Solvents?
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Residual solvents refer to traces of solvents like butane, propane, or alcohol left behind after the process of extracting cannabinoids and terpenes from cannabis plant material.
Solvents dissolve trichome resin glands and draw out desired compounds. But trace amounts may remain in the final concentrates if not fully purged.
Common solvents include hydrocarbon gases like butane for BHO waxes and shatters or ethanol for distillates and tinctures.
CO2, ice water, or mechanical separation can also be used for solventless extractions. Testing residual solvent levels ensures consumer safety.
Safety of Residual Solvents
Residual solvents can be harmful if consumed, especially isopropyl alcohol and certain hydrocarbons. Allowable levels depend on the solvent but are strictly regulated.
Legal state markets mandate safe limits through required testing. Consumers should check lab results and avoid buying untested products.
Proper purging equipment and techniques minimize residual solvents by heating and agitating extracts to fully evaporate any remaining traces after initial filtration.
Vacuum ovens and other closed-loop systems provide consistent heat and pressure control for optimal purging. High levels indicate poor practices.