Isopropanol works well, and is probably the safest choice. I cannot comment on carcinogens in pharmaceutical grade isopropanol, but it would seem that it should be minimal. Acetone (pure, not diluted) also works well, and evaporates much faster. USP grade acetone is available and should be reasonably safe (from a health perspective). However acetone has a much lower flash point than isopropanol, so you have to be doubly careful about fires. Don't put acetone in a rice cooker (they're too hot). A double boiler on very low heat would work well (acetone boils at 56C; isopropanol boils at 83C). Also, acetone fumes are far more overwhelming (at least to me) than isopropanol, so be sure to have adequate ventilation. 30-60 pet ether (petroleum ether, 30-60 degree 'cut') or hexane will also work well. I don't know if USP grades of these solvents are available. It's similar to "white gas", but I would not use "white gas" due to impurities. These solvents also evaporate rapidly (like acetone), and have the advantage of extracting much less chlorophyll than acetone or isopropanol. Ethanol (USP or everclear - NOT denatured) is great for tinctures. Actually, you can use any distilled alcohol with an alcohol content over 50% to make a tincture (cask strength scotch or bourbon works well, and tastes mighty good; 151 rum also works well). Extract the plant material a couple of times. Tinctures made from alcohol will contain significant amounts of chlorophyll, but no more than you'd eat in a good helping of spinach. Unless you are especially sensitive to leafy greens, you are not likely to get chlorophyll poisoning. It takes a LOT of chlorophyll to make a person sick.

Have any of you ever had your oil tested?

"Bob"