PDFWAC 314-55-430
Qualifying patient or designated provider extraction requirements.
(1) Qualifying patients or designated providers, including those participating in a cooperative, may extract or separate the resin from cannabis using only the following noncombustible methods:
(a) Heat, screens, presses, steam distillation, ice water, and other methods without employing combustible solvents or gases to create kief, hashish, or bubble hash;
(b) Dairy butter, cooking oils or fats derived from natural sources, or other home cooking substances;
(c) Food grade glycerin and propylene glycol solvent based extraction;
(d) CO2 may be used if used in a closed loop system as referenced in WAC 314-55-104.
(2) Only food grade substances may be used in any stage of processing.
(3) Use of combustible materials including, but not limited to, butane, isobutane, propane, heptane, and ethanol is expressly forbidden.
(4) Resins extracted or separated from cannabis are for the personal use of the qualifying patient or cooperative members only.