BadKittySmiles, I appreciate the effort you've put forth in explaining your methodology, but as I said before, this is what I know works for me within the parameters and limitations that I have. I get enough trim from each grow to make over 1000 pieces of candy. (although to be honest, I rarely make more than two batches of candy at a time) It only takes two of those pieces to finish me off. Why would I need anything more? I do not suffer from a shortage of product. BHO is the easiest method of extraction for me because it requires no thought. Load it up, run the butane through, collect the sticky stuff, purge it. I'm not in it for any extra lengthy procedures. Edibles are not my primary focus. Growing nugs is. The BHO and the candy I make with it are just a bonus. So I will politely ask that if you wish to continue to extol the virtues of lipids, glycerides and fatty acid chains or whatever, please do so in another thread. People looking for that information may not necessarily turn to this thread for answers. I have already said that I am not interested in additional processing, because the method I described in my first post already works satisfactorily enough for me, and should also work for anybody else with similar considerations. Again, thank you.
As for the safety of butane in food products: Butane is generally recognized as safe (GRAS) by the FDA for use in the production of food as a solvent (typically for oils used in flavorings), refrigerant (least toxic refrigerant gas) and propellant (in products like PAM). OSHA and the CDC concluded that prolonged exposure to inhaled butane at levels of 500ppm for 8 hours a day, five days a week for two weeks did not induce any toxicity or narcotic effects in the volunteer test subjects. If you do everything correctly, I would be surprised if you have trace levels of butane higher than 20ppm. To put that in perspective, at 20ppm, if you had 15ml of BHO, you would only find 0.3 microliters of butane in it. As butane is present in natural gas, you probably inhale more than that just lighting your stove.
With that being said, I will acknowledge that there are some very real dangers to using butane as a solvent. However those dangers do not come from ingesting trace amounts.
Flammability - this is a no brainer. Do it outside, and don't have any open flames or sources of ignition near by. Even if you're using a closed recovery system. This risk also exists when you purge the oil. Always purge outside.
Contamination - Not necessarily from the butane itself, but from the materials used in the extraction apparatus. Contrary to popular belief, PVC and butane are not compatible. PVC is susceptible to attack by butane, and will actually dissolve into solution after repeated use. Stainless steel, aluminum or glass are all much better options than PVC. Also, you need to use pure butane. Camp stove fuel will not do. It has propane and mercaptans in it. Lucienne and other "refined" lighter fuel will suffice, but 99.5% or higher from Airgas or Praxair are the best.
Asphyxiation - Butane displaces oxygen. Aside from the risk of fire, this is the next most important reason not to use butane indoors.
Intoxication - If you inhale butane, you will get messed up. Not in a good way. Again, doing your extraction outside will reduce the risk of this.
These are risks that can be mitigated through proper techniques and procedures. They are risks that I will gladly live with when compared to other techniques that use hexane, isopropyl alcohol, acetone or MEK, which are all much more toxic than butane. Butane gets a lot of grief over impurities and toxicity that is simply unfounded. Meanwhile, other methods are being promoted that use known poisons. In my opinion, there is no comparison.