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Decarboxylation

Cannabis produces phyto cannabinoids in a carboxylic acid form that are not orally active at least at the CB-1 receptor sites, because they don't readily pass the blood brain barrier in their polar form.

To enable them to pass the blood brain barrier, they must first be decarboxylated, to remove the COOH carboxyl group of atoms, which exits in the form of H20 and CO2.

Decarboxylation occurs naturally with time and temperature, as a function of drying, but we can shorten the amount of time required considerably, by adding more heat.  The more heat, the faster it occurs, within reasonable ranges, and in fact occurs spontaneously when the material is burned or vaporized.

There is another mechanism at play however, which suggests that we need to control the decarboxylation temperatures carefully.

When we heat cannabis to convert the THCA and CBDA into THC and CBD, we are also converting THC to CBN at a faster rate.  At about 70% decarboxylation, we actually start converting THC to CBN at a faster rate than we are converting THCA to THC, so as you can see by the following graph, after about 70% decarboxylation, the levels of THC actually start to fall sharply.

That of course means that the CBN also begins to rise and the medication is becoming more sedative.

Thank you Jump 117 for this excellent graph!

Decarboxylation Graph-1-1 Decarboxylation graph

Another fly in the ointment, is that we can never know for sure exactly what the starting state of decarboxylation is, so the times at temperature shown on the graphs are an average.

We can't expect dry material placed in an oven at any given temperature to be that uniform temperature throughout instantly upon placing it in a heated oven, nor know for sure the state of decarboxylation by simple observation.

Decarboxylating plant material, also alters the taste (roasted/toasted), which some find less agreeable, and of course decarboxylating also evaporates away the smaller Monoterpenes and Sequiterpenes alcohols, phenols, ketones, aldehydes, ethers, and esters.

The good news is that it is dirt simple to monitor the state of cannabis oil decarboxylation placed in a 121C/250F hot oil bath, because you can watch the CO2 bubble production.

Just like the curves suggest, CO2 bubble production will proceed at its own observable rate. By keeping the puddle of oil lightly stirred on the bottom and in the corners of the pot (I use a bamboo skewer), so as to keep the bubbles broken free and floating to the top, you can tell exactly when the bubble formation suddenly tapers off at the top of the curve.

That is the point that we take it out of the oil for maximum head effect, and we leave it in until all bubbling stops, if we want a more sedative night time med.

Here are a couple pictures of what oil looks like when boiling off the residual butane.  Residual butane or alcohol produces larger, randomly sized bubbles, and is fully purged, when they cease.

I am seemingly missing the middle picture of the CO2 bubbles, so I will add it later, but the second picture shows what fully decarboxylated oil looks like.

Residual solvent bubbles aboveQuiescent oil.

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395 Comments

  1. wakeandbakecookbook

    I have some readers asking about a variation of this. If you put bud in coconut oil and heat it, can you tell what stage of decarb it is in by the bubbles being released? If so, shouldn't we skip oven decarb completely and decarb straight in oil?

    Reply
  2. It isn’t all about the THC, baby | Thinc

    […] of the cannabinoid family. In order for CBC to even exist in cannabis, the cannabis must go through decarboxylation. This particular cannabinoid shows great promise in treating cancer; it is said to inhibit the […]

    Reply
  3. john anita

    Hello are you looking for quality and pure cannabis oil email Dr Richard @ drrichardmedicaloil@gmail.com i can assure you that, this is where you can get your pure hemp from.

    Reply
  4. buddhabrother

    Is it possible to heat it too long? I am using a magnetic stir plate and the cavitation appears to form tiny bubbles like you would expect to see while decarbing. Would I see spikes or drops in my analysis if it were to be heated for too long. I do occasionally stop the stir rod to check to see if bubbles stop forming, and I stopped the process when I had observed that the reaction had slowed dramatically Magnetic stir hot plate double boiled oil bath pyrex/labflask stir rpm about 1k Testing results http://imgur.com/rKI6oJ9 Thanks again for your help guys, don't know what I would do without this place.

    Reply
    1. Skunk Pharm Research,LLC

      It is possible to heat too long if you are trying to maximize THC and CBD. https://skunkpharmresearch.com/decarboxylation/ Note that about 70% decarboxylation, that the curve falls off sharply. If you are watching the process and keeping accumulated bubbles minimized, you can tell from the new bubble formation, precisely when you hit the top of that curve and start down the other side. Carla has at least one patient that wants his evening meds decarboxylated 100% at the very least, and prefers meds from a vapor pipe's reclaim. GW

      Reply
  5. Robyn

    I have decarboxylated CBD oil. Can I bake with it or does it need to be consumed in the raw form such as on the tongue, or a drop on a pre-baked cookie? Any advice is appreciated.

    Reply
  6. MattMatt

    With respect that is a ridiculous comment. Decarboxylation is needed if you are eating cannabis. Simple as that. Cannabis does not decarb in the stomach, raw THCA is very different to THC, not just because it doesn't get you high but medicinally too. And what possible marketing would be involved in telling people they need to cook their cannabis?

    Reply
    1. Matt

      It is only needed it you are eating raw material, drying the marijuana is decarboxylating. I was wrong about your body converting THCA into THC, but this is due to complex chemistries in metabolism. It is a common practice in chemistry to decarboxylate in the presence of HCl acid.

      Reply       Edit
      1. hempshare

        THC is not water soluble and must be dissolved into lipid fat so it can be metabolized in the body. "Smoking" is technically - Vaporizing with "bio-mass". It just happens that Vaporizing with "bio-mass" as a heat source is not very efficient, and a must higher ratio of THCA:THC enters the body this way. Hence, some people insist they love "smoking joints". Of course they love smoking joints because this provides them a greater balance of Two Platonic Solids, Hexahedron and Tetrahedron.

        Reply
  7. Outoftime

    I understand this thread but I don't understand whether to hear the BHO to 250 in the oil for my recipe (coconut oil, avocado oil, butter etc) If one heats the wax in other oils, does the "it's done when the bubbles taper off" instruction still hold? I only plan to use 1g of earwax for a pan of 12 brownies. Any advice would be appreciated.

    Reply
  8. Dr Decarb

    Based on the above chart, I developed what I think is a completely unique and sure fire way to get max THC, and for the most part all other cannabinoids, in a process that takes less than 2 hours and produces very potent infusions into any fatty oil which is stable up to 300F. I`ll post the how-to below, but the basics are to PREHEAT your fatty oil to 250F then dump your dry good into the hot oil. Decarb begins more a less instantly with no guessing about the rise time for temperatures, and everything in the plant goes into and stays in the oil. You just need to maintain around 250F for about 25-28 minutes. Materials: Min. .25 oz ground Cannabis 100ML Coconut Oil 250F Meat Thermometer 6 inch Stainless Steel Sauce Pan (high quality, heavier gauge preferred) 10-12 inch Pyrex Pie Plate Gas or Electric range or other suitable pan warmer Coffee filter, or other preferred straining device How To: With Meat Thermometer in Saucepan, place 100ML Coconut Oil in pan on low heat until 255F is reached. If doing the small .25 batch, take great care that you only measure the oil temp and that the Meat Thermometer does not contact the side or bottom of the pan when doing so. I measured a 20-30F difference vs. just leaving the Meat Thermometer in place with the pan still flat on the burner. I found tilting the pan to pool the Coconut Oil is the only way to get an accurate reading. Although larger batches would likely be easier to monitor and measure. Once a stable temp is attained pour and stir entire quantity of Cannabis into preheated Coconut Oil and simmer maintaining 250F for 25-28 minutes. Stir frequently. Then remove from heat and pour Coconut Oil/Cannabis mix onto the Pie Plate. Let stand for 3-4 minutes. Strain, refrigerate. While the simmering temp is 250F, the preheat temp is 255F, as I speculated a drop in temp when the Cannabis is dumped in. Also be absolutely certain your dry goods are really dry goods. At 250F there was a little foam up when placed into the hot oil, but I could see where undried Cannabis could be a problem, especially if temps were higher that measured. Don`t let the Coconut Oil exceed appox. 270F at any time, as there begins to be discoloration at around 280, and smoke at around 300F. The concept behind this is to produce a quick, reliable, reproducible, method for a potent Coconut Oil Infusion based on a precise decarboxylation method. I decided on the 252/30 minute profile, allowing for some continued conversion by shortening it a bit. I did the process in about an hour, however it could very leisurely, and carefully done by less experienced people in 2 hrs. I’ve never had much success with either my own, or other peoples edibles (except a micro batch of CO I did), but this method, at least for me, has produced 4 straight VERY STRONG infusions. Two .25 teaspoon doses an hour apart in the morning produces a high I can still feel late into the afternoon. If you let it linger in your mouth before swallowing you will feel a slight buzz about 5 minutes after, but the real peak takes about 1.5 to 2 hrs. My starting material is just average. High quality medical would no doubt produce superbly medicinal and psychoactive infusions.

    Reply
  9. MattMatt

    No, if you don't decarb then it will be mostly THCA or CBDA, depending on strain. Decarboxylation converts the THCA to THC and the CBDA to CBD. If you do not decarb then there will be little to no CBD, it will be CBDA. It is true that you don't need to decarb if you are vaporising or smoking it (as the heat involved will decarb it anyway). Decarboxylation is only need if you are eating it. For some conditions the raw may be a better option. There is a lot of evidence, though mostly anecdotal at this stage, that raw THCA is actually better than CBD for epilepsy as many Dravet's patients are reporting better results with THCA tinctures than with CBD dominant oils. But it is important to remember that decarboxylation is needed to convert the raw cannabinoid acids like THCA and CBDA to THC and CBD. Raw does not have CBD or THC, it is THCA and CBDA. If you want CBD then you need a strain with high CBD, but in its raw form it will be CBDA and you need to decarb it to make it CBD. Same goes for converting THCA to THC, CBGA to CBG, CBCA to CBC, CBNA to CBN etc.

    Reply
  10. MattMatt

    yes, if you are smoking or vaporising then you do not need to concern yourself with decarboxylation as it happens through the heat involved in smoking or vaping. In fact many people prefer not to decarb if they are going to smoke or vaporise as full decarb usually causes a loss of most of the terpenes which give the smell and flavour. Decarboxylation is only important if you are going to eat the cannabis. Then you need to decarb fully because raw THCA does not get you high (and is less medicinally active for many things including cancer) so unconverted THCA eaten is a waste from a getting high point of view. Full decarb is giving you maximum THC when eating, but smoking it then THCA or THC will be THC when you inhale, so decarb won't matter

    Reply
  11. Will Harrison

    Can you vac oven flowers to get complete conversion of THCa to THC while maintaining all the terpenes, if one was inclined to do so :)

    Reply
  12. DJ_Rocari

    sorry, I am lost. you say ... "as you can see by the following graph, after about 70% decarboxylation, the levels of THC actually start to fall sharply."... excuse me, where exactly in the graph is that "70%"? and where exactly, in which curve "THC falls"? thanks so much

    Reply
  13. klaatu

    Greetings GW. I have been blessed by your shared wisdom in these matters for a long time now, well before this site gathered so much of it together, and added so immensely to it. You have scattered cogent posts among various older forums, and it wasn't so conveniently arranged as it has now become. Thank you for your persistent contributions, exemplary vision and truly public service I haven't commented or written ever before, I typically work pretty silently in the back of the back room, but now your well sustained open spirit is infecting even me. I would be very grateful to hear what you might say in clarification of something having to do with all this, should you wish to... "many of the terpenes (d-limonene, linalool, mycrene, a-pinene etc.) are evaporated off when you decarboxylate cannabis oil" I have seen this statement, or one like it, many times, here and elsewhere. I find this more than somewhat confusing, since the boiling points of these terps are all quite high, well above normal decarb temps: Limonene Boiling point 176 °C (349 °F; 449 K) https://en.wikipedia.org/wiki/Limonene Linalool Boiling point 198–199 °C https://en.wikipedia.org/wiki/Linalool Myrcene Boiling point 166-168 °C https://en.wikipedia.org/wiki/Myrcene Pinene Boiling point 155 °C (311 °F; 428 K) https://en.wikipedia.org/wiki/A-Pinene Terpinolene Boiling points a: 173.5-174.8 °C https://en.wikipedia.org/wiki/Terpinolene With the exception of Pinene, these are all higher temps than the boiling point of THC itself Some time ago, after quite a bit of study on an extraction issue, I found an old patent from the 50s that dealt with *removing* terpenes from essential oils used in the fragrance industry, because they would break down during the distillation or storage and produce off smells: "natural oils contain terpenes and sesquiterpenes which, in general, oxidize readily in the air with the development of unpleasant odors and flavors" http://www.google.com/patents/US2712008 Some of the wiki articles on these canna terps also mention this degradation. Humulene is especially reactive with atmospheric ozone in sunlight, with a lifetime of a couple minutes. This decomposition of terpenes results from exposure to heat, light, and oxygen. This is why they are so ephemeral, they decompose very readily, especially with heating, like during decarb. It would not seem that they vanish rapidly due to evaporation at these temps that are quite below their boiling points. also from this patent: "The terpenes may be recovered ... by distillation. Vacuum distillation is preferred to minimize decomposition of the terpenes." If the terpenes are heated enough to boil/evaporate, then they have already decomposed instead, unless it is done under vacuum at much lower temps. They do vaporize to some degree at temps below their boiling points, like water slowly disappearing out of a drinking glass at room temp. That's why we smell them. But their woeful loss during these extraction and decarb procedures does not appear to me to be due to evaporation, like so many enthusiasts seem to think, and say. This patent also makes note of 'terpenophilic solvents', down near the bottom, in the claims. Non-polar hexane is very terpenophilic. Other solvents are non-terpenophilic, like acetone, which they used to extract everything but the terps. My feeling on all this is that the absence of satisfying terp levels in various procedural results is much less because they evaporated, and much more because they decomposed along the way, or perhaps weren't all that present to begin with because of the use of a non-terpenophilic solvent Kind regards. Comments invited

    Reply
    1. skunkpharmresearch

      Morning Klaatu! An interesting theory, and well presented! Good job! I pulled the vapor pressures of the monoterpenes in question and some are indeed suspiciously low given their aromatic nature, lending credence to the theory that what we are smelling, is not just molecules escaping low intermolecular forces and colliding with our noses, but the degradation products of the terpenes that were cast off, colliding with our noses. I copied the patent in question, and will review it in greater detail, as well as ask our biotech Joe to join me in analyzing the issue. More after doing so. Thanks for the insight! Peace, GW

      Reply
  14. Joe C

    Ive been searching the interwebs in order to create a specific oil to aid a family friend with type 1 diabetes... From what i can gather, CBN is what i'm trying to amplify. With that in mind & based on the fact TCH converts to CBN if decarb'd longer, how long would you leave it @ 250 - 270 F ?? Cheers, Joe

    Reply
  15. Nir

    Hello, so i made the OIL using 96% drinking alcohol (frozen), i tried a different kind of Decarboxylation method and those are the results of the lab test - the method of testing was HPLC1,2 - THC - 68.88, THCA - undetectable, CBN - 0.6%. So it looks like i have made 99.4% of THCA Decarboxylate into THC with no conversion to CBN. what do you think? (the OIL is Cristal clear amber color).

    Reply
      1. Nir

        Hi, i am going to do this one more time soon to see if i can Repeat those results, and if so i will explain what i have done.... nothing too special :-)

        Reply
  16. Steve Weglein

    Hi All, I have a question about decarboxylation as it applies to my wifes medication. We are slowly dosing her up to 3 large drops, 4 times daily. We are trying to reduce or eliminate her need for blood pressure medicine, which she has needed and taken for over 30 years. Currently we are up to 10 drops a day ... almost up to full dosage. My wife (all 100 pounds of her) is now being affected by the THC, pretty strongly ... I decarboxylate her HAO fully at 250f. Her meds are made from Skywalker OG, which has virtually no CBD, btw (I am still unable to get cbd clones, sheesh). She does not enjoy being 'blasted' .... After reading some recent comments here regarding CB1 and CB2 receptors, I began thinking that maybe her meds might be just as effective, without much decarboxylation, if it is the CB2 receptors that are involved in BP So the question is, can I prepare my wifes meds without decarboxylating intentionally, and still get the blood pressure regulating effects? Ideally, in 3 or so months, CBD bearing plants can be grown and harvested, and over time the 'blasted' effect should come more under control, I suppose, anyway ... but producing less decarboxylated meds would make her life easier for the moment. We are down a full 25% on her bp meds btw. Thank you for all your help Steve Weglein

    Reply
    1. skunkpharmresearch

      Hi Steve! You can use the meds without decarboxylation and should still get the BP reduction, but the stuff will be highly unstable. Keep it sealed and in the frig when not using, because heat will decarboxylate it after the fact. Not sure how dropper-able it will be, but if it is too stiff, you can stuff it into caps.

      Reply
      1. Steve Weglein

        OMG .... I made a 5g batch of Skywalker OG with a QWET process. As I cooked of a liter of everclear (used to extract 70g flowers), I am sure some decarboxylation occurred, but not much as I kept the temp moderate. When I was sure the alcohol was boiled off completely, I stopped, and when cool added the HAO ingredients. I heated the solution to 185f, stirred to make sure it was well mixed and removed from heat ..... my guess is less than 20% decarboxylated, and perhaps less than 10%! The resulting solution is still 'droppable' .... no prob there. The effect was profound ..... much more of an initial effect ..... her bp at the next measurement to hours later was 108/ 65 .... and she had only taken bp meds several hours before. She was also, as expected, less 'wasted'. Her bp was slightly elevated before bed ... a 3 bp med day. Today will be the first full day ..... carboxylated ..... I will keep you posted. Though I am now wondering at whether it is so critical, I finally managed to score a clone of the Harequin variety ... 9-10% CBD ...... 3 months til 1st cbd harvest, unless you think perhaps juicing it might be worth a try (which could be done sooner). All good here .... 'high' expectations for todays readings .... we are at `` drops per day ...... full dose starts this Saturday ...... YES!!!!! Again thank you for all your help Steve ps as hypertension is NOT yet a very 'advertised' beneficiary of Cannabis treatment, perhaps a thread here might be in order ..... 'jes sayin' ;-)

        Reply
        1. skunkpharmresearch

          Cannabis certainly controls my hyper tension. When I take Hyzar in the morning, when I wake up the next morning, my blood pressure is 150/160-80/90, so I take the Hyzar at night. When I wake up, my blood pressure is around 115/70, and after medicating with cannabis, it stays that way until bedtime.

          Reply
          1. Mainah

            Just wanted to throw my 2 bits in here...I've had hypertension all my life, on pills since the age of 20. I'm now 55. I was taking 4 pills a day, all very high dose, for BP until I started using cannabis to treat peripheral neuropathy about 3 years ago with a vaporizer. I was able to drop 2 meds within a couple months. 2 years ago my wife and I became vegans. That eliminated one more and got the remaining atenolol down to 25 mg from 100. Until recently my medible consumption has been sporadic. I have recently discovered oil works miracles for my pain, and is lowering my BP further as well. I hope to be pill free at some point, and pain free! I've also always had astronomical cholesterol and triglyceride numbers. Same story, cannabis got me about half way there and becoming vegan did the rest. I'm now off the meds altogether and holding steady under 200 total cholesterol with my best reading at 117 so far. Best wishes and love to you and your wife Steve. You're on the right path, and in the right place to get the best help for her. Mainah

            Reply
          2. Mainah

            I forgot to mention that I started using some Cannatonic just recently, the first high CBD strain I have grown. Not sure what the effect on BP will be yet, but the pain relief is stellar compared to anything I've had before. High CBD is absolutely worth seeking out IMHO. I'm just starting to make and take oil, and I want to get the ingredients to try HAO next. Thanks for the recipe GW and ES!

            Reply
  17. Steve Weglein

    When I look at the decarboxylation chart provided, I see a quicker decarboxylation point at 293f. I am not sure why you recommend the 252f temperature ..... are there other medicinal terpenes that are lost at the higher temperature, or?

    Reply
  18. scubadoo

    Apparently in Europe, Naptha is called Benzine. I am not an expert or a scientist but am only stating that this method works to kill cancer. Whether using Naptha or ISO, the trick is to wait until all the Naptha or ISO has evaporated when boiling with a rice cooker. With the batches i made, you cannot taste the solvent & the potency is very good. The starting product is obviously important for the potency & medicinal properties. My wife has also been taking Essiac tea along with the oil. This tea has been used successfully in the past to treat cancer. This can be verified by watching youtube video "Cancer-The forbidden cures". The tea seems to help settle the stomach in the morning we find.

    Reply
    1. skunkpharmresearch

      Thanks for the heads up on the Essiac Tea and The forbidden cures video bro! Good point on Benzene, as some light naphtha contains Benzene, which is is of major concern: Consider this from Wiki: Health effects A bottle of benzene. The warnings show benzene is a toxic and flammable liquid. Benzene increases the risk of cancer and other illnesses. Benzene is a notorious cause of bone marrow failure. Substantial quantities of epidemiologic, clinical, and laboratory data link benzene to aplastic anemia, acute leukemia, and bone marrow abnormalities.[43][44] The specific hematologic malignancies that benzene is associated with include: acute myeloid leukemia (AML), aplastic anemia, myleodysplastic syndrome (MDS), acute lymphoblastic leukemia (ALL), and chronic myeloid leukemia (CML).[45] The American Petroleum Institute (API) stated in 1948 that "it is generally considered that the only absolutely safe concentration for benzene is zero."[46] The US Department of Health and Human Services (DHHS) classifies benzene as a human carcinogen. Long-term exposure to excessive levels of benzene in the air causes leukemia, a potentially fatal cancer of the blood-forming organs, in susceptible individuals. In particular, Acute myeloid leukemia or acute nonlymphocytic leukemia (AML & ANLL) is not disputed to be caused by benzene.[47] IARC rated benzene as "known to be carcinogenic to humans" (Group 1). Human exposure to benzene is a global health problem.[vague] Benzene targets liver, kidney, lung, heart and the brain and can cause DNA strand breaks, chromosomal damage, etc. Benzene causes cancer in both animals and humans. Benzene has been shown to cause cancer in both sexes of multiple species of laboratory animals exposed via various routes.[48][49] Some women who inhaled high levels of benzene for many months had irregular menstrualperiods and a decrease in the size of their ovaries. Benzene exposure has been linked directly to the neural birth defects spina bifida andanencephaly.[50] Men exposed to high levels of benzene are more likely to have an abnormal amount of chromosomes in their sperm, which impacts fertility and fetal development.[51] [edit]Exposure to benzene Light refraction of benzene (above) and water (below) Vapors from products that contain benzene, such as glues, paints, furniture wax, and detergents, can also be a source of exposure, although many of these have been modified or reformulated since the late 1970s to eliminate or reduce the benzene content. Air around hazardous waste sites or gas stations may contain higher levels of benzene. Because petroleum hydrocarbon products are complex mixtures of chemicals, risk assessments for these products, in general, focus on specific toxic constituents. The petroleum constituents of primary interest to human health have been the aromatic hydrocarbons (i.e., benzene, ethylbenzene, toluene, and xylenes). In the U.S., OSHA requires that a mixture "shall be assumed to present a carcinogenic hazard if it contains a component in concentrations of 0.1% or greater, which is considered to be a carcinogen.[52][53] Outdoor air may contain low levels of benzene from automobile service stations, wood smoke, tobacco smoke, the transfer of gasoline, exhaust from motor vehicles, and industrial emissions.[54] About 50% of the entire nationwide (United States) exposure to benzene results from smoking tobacco or from exposure to tobacco smoke.[55] [edit]Inhalation Inhaled benzene is primarily expelled unchanged through exhalation. In a human study 16.4 to 41.6% of retained benzene was eliminated through the lungs within five to seven hours after a two- to three-hour exposure to 47 to 110 ppm and only 0.07 to 0.2% of the remaining benzene was excreted unchanged in the urine. After exposure to 63 to 405 mg/m3 of benzene for 1 to 5 hours, 51 to 87% was excreted in the urine as phenol over a period of 23 to 50 hours. In another human study, 30% of absorbed dermally applied benzene, which is primarily metabolized in the liver, was excreted as phenol in the urine.[56] [edit]Exposure through smoking Exposure of the general population to benzene occurs mainly through breathing, the major sources of benzene being tobacco smoke (about 50%) as well as automobile service stations, exhaust from motor vehicles and industrial emissions (about 20% altogether). According to the CDC, "The mean number of cigarettes per day (cpd) among daily smokers in 1993 was 19.6 (21.3 cpd for men and 17.8 cpd for women) and in 2004 was 16.8 (18.1 cpd for men and 15.3 cpd for women)."http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5444a2.htm According to the August 2007 Public Health Statement, the average smoker smokes 32 cpd, which in turn the average smoker would take in about 1.8 milligrams (mg) of benzene per day. This amount is about 10 times the average daily intake of benzene by nonsmokers.[57] [edit]Exposure from soft drinks In March 2006, the official Food Standards Agency in Britain conducted a survey of 150 brands of soft drinks. It found that four contained benzene levels above World Health Organization limits. The affected batches were removed from sale.[58] (See also benzene in soft drinks). [edit]Case examples Water and soil contamination are important pathways of concern for transmission of benzene. In the US alone, approximately 100,000 sites have soil or groundwater contaminated with benzene.[citation needed] In 2005, the water supply to the city of Harbin in China with a population of almost nine million people, was cut off because of a major benzene exposure. Benzene leaked into the Songhua River, which supplies drinking water to the city, after an explosion at a China National Petroleum Corporation (CNPC) factory in the city of Jilin on 13 November.[citation needed] [edit]Benzene exposure limits The United States Environmental Protection Agency has set a maximum contaminant level (MCL) for benzene in drinking water at 0.005 mg/L (5 ppb), as promulgated via the U.S. National Primary Drinking Water Regulations.[59] This regulation is based on preventing benzene leukemogenesis. The maximum contaminant level goal (MCLG), a nonenforceable health goal that would allow an adequate margin of safety for the prevention of adverse effects, is zero benzene concentration in drinking water. The EPA requires that spills or accidental releases into the environment of 10 pounds (4.5 kg) or more of benzene be reported. The U.S. Occupational Safety and Health Administration (OSHA) has set a permissible exposure limit of 1 part of benzene per million parts of air (1 ppm) in the workplace during an 8-hour workday, 40-hour workweek. The short term exposure limit for airborne benzene is 5 ppm for 15 minutes.[60] These legal limits were based on studies demonstrating compelling evidence of health risk to workers exposed to benzene. The risk from exposure to 1 ppm for a working lifetime has been estimated as 5 excess leukemia deaths per 1,000 employees exposed. (This estimate assumes no threshold for benzene's carcinogenic effects.) OSHA has also established an action level of 0.5 ppm to encourage even lower exposures in the workplace.[61] The U.S. National Institute for Occupational Safety and Health (NIOSH) revised the Immediately Dangerous to Life or Health (IDLH) concentration for benzene to 500 ppm. The current NIOSH definition for an IDLH condition, as given in the NIOSH Respirator Selection Logic, is one that poses a threat of exposure to airborne contaminants when that exposure is likely to cause death or immediate or delayed permanent adverse health effects or prevent escape from such an environment [NIOSH 2004]. The purpose of establishing an IDLH value is (1) to ensure that the worker can escape from a given contaminated environment in the event of failure of the respiratory protection equipment and (2) is considered a maximum level above which only a highly reliable breathing apparatus providing maximum worker protection is permitted [NIOSH 2004[62]].[63] In September 1995, NIOSH issued a new policy for developing recommended exposure limits (RELs) for substances, including carcinogens. Because benzene can cause cancer, NIOSH recommends that all workers wear special breathing equipment when they are likely to be exposed to benzene at levels exceeding the REL (10-hour) of 0.1 ppm.[64]The NIOSH STEL (15 min) is 1 ppm. American Conference of Governmental Industrial Hygienists (ACGIH) adopted Threshold Limit Values (TLVs) for benzene at 0.5 ppm TWA and 2.5 ppm STEL. [edit]Exposure monitoring Airborne exposure monitoring for benzene must be conducted in order to properly assess personal exposures and effectiveness of engineering controls. Initial exposure monitoring should be conducted by an industrial hygienist or person specifically trained and experienced in sampling techniques. Contact an AIHA Accredited Laboratory for advice on sampling methods.[65] Each employer with a place of employment where occupational exposures to benzene occur shall monitor each of these workplaces and work operations to determine accurately the airborne concentrations of benzene to which employees may be exposed.[66] Representative 8-hour TWA employee exposures need to be determined on the basis of one sample or samples representing the full shift exposure for each job classification in each work area. Unless air samples are taken frequently, the employer does not know the concentration and would not know how much of a protection factor is needed.[67] In providing consultation on work safety during oil clean-up operations following the Deepwater Horizon accident, OSHA has worked with a number of other government agencies to protect Gulf cleanup workers. OSHA partnered with the NIOSH to issue "Interim Guidance for Protecting Deepwater Horizon Response Workers and Volunteers" and recommend measures that should be taken to protect workers from a variety of different health hazards that these workers face.[68] OSHA conceded that it recognizes that most of its PELs are outdated and inadequate measures of worker safety. In characterizing worker exposure, OSHA instead relies on more up-to-date recommended protective limits set by organizations such as NIOSH, the ACGIH, and the American Industrial Hygiene Association (AIHA), and not on the older, less protective PELS. Results of air monitoring are compared to the lowest known Occupational Exposure Limit for the listed contaminant for purposes of risk assessment and protective equipment recommendations.[69] [edit]Biomarkers of exposure Several tests can determine exposure to benzene. Benzene itself can be measured in breath, blood or urine, but such testing is usually limited to the first 24 hours post-exposure due to the relatively rapid removal of the chemical by exhalation or biotransformation. Most persons in developed countries have measureable baseline levels of benzene and other aromatic petroleum hydrocarbons in their blood. In the body, benzene is enzymatically converted to a series of oxidation products including muconic acid, phenylmercapturic acid, phenol,catechol, hydroquinone and 1,2,4-trihydroxybenzene. Most of these metabolites have some value as biomarkers of human exposure, since they accumulate in the urine in proportion to the extent and duration of exposure, and they may still be present for some days after exposure has ceased. The current ACGIH biological exposure limits for occupational exposure are 500 μg/g creatinine for muconic acid and 25 μg/g creatinine for phenylmercapturic acid in an end-of-shift urine specimen.[70][71][72][73] [edit]Biotransformations Even if it is not a common substrate for the metabolism of organisms, benzene can be oxidized by both bacteria and eukaryotes. In bacteria, dioxygenase enzyme can add an oxygen molecule to the ring, and the unstable product is immediately reduced (by NADH) to a cyclic diol with two double bonds, breaking the aromaticity. Next, the diol is newly reduced by NADH to catechol. The catechol is then metabolized to acetyl CoA and succinyl CoA, used by organisms mainly in the Krebs Cycle for energy production. The pathway for the metabolism of benzene is complex and begins in the liver. Several key enzymes are involved. These includecytochrome P450 2E1 (CYP2E1), quinine oxidoreductase (NQ01), GSH, and myeloperoxidase (MPO). CYP2E1 is involved at multiple steps: converting benzene to oxepin (benzene oxide), phenol to hydroquinone, and hydroquinone to both benzenetriol and catechol. Hydroquinone, benzenetriol and catechol are converted to polyphenols. In the bone marrow, MPO converts these polyphenols to benzoquinones. These intermediates and metabolites induce genotoxicity by multiple mechanisms including inhibition of topoisomerase II (which maintains chromosome structure), disruption of microtubules (which maintains cellular structure and organization), generation of oxygen free radicals (unstable species) that may lead to point mutations, increasing oxidative stress, inducing DNA strand breaks, and altering DNA methylation (which can affect gene expression). NQ01 and GSH shift metabolism away from toxicity. NQ01 metabolizes benzoquinone toward polyphenols (counteracting the effect of MPO). GSH is involved with the formation of phenylmercapturic acid.[45][74] Genetic polymorphisms in these enzymes may induce loss of function or gain of function. For example, mutations in CYP2E1 increase activity and result in increased generation of toxic metabolites. NQ01 mutations result in loss of function and may result in decreased detoxification. Myeloperoxidase mutations result in loss of function and may result in decreased generation of toxic metabolites. GSH mutations or deletions result in loss of function and result in decreased detoxification. These genes may be targets for genetic screening for susceptibility to benzene toxicity.[75] [edit]Molecular toxicology The paradigm of toxicological assessment of benzene is shifting towards the domain of molecular toxicology as it allows understanding of fundamental biological mechanisms in a better way. Glutathione seems to play an important role by protecting against benzene-induced DNA breaks and it is being identified as a new biomarker for exposure and effect.[76] Benzene causes chromosomal aberrations in the peripheral blood leukocytes and bone marrow explaining the higher incidence of leukemia and multiple myeloma caused by chronic exposure. These aberrations can be monitored using fluorescent in situ hybridization (FISH) with DNA probes to assess the effects of benzene along with the hematological tests as markers of hematotoxicity.[77] Benzene metabolism involves enzymes coded for by polymorphic genes. Studies have shown that genotype at these loci may influence susceptibility to the toxic effects of benzene exposure. Individuals carrying variant of NAD(P)H:quinone oxidoreductase 1 (NQO1), microsomal epoxide hydrolase (EPHX) and deletion of the glutathione S-transferase T1 (GSTT1) showed a greater frequency of DNA single-stranded breaks.[78] [edit]Biological oxidation and carcinogenic activity One way of understanding the carcinogenic effects of benzene is by examining the products of biological oxidation. Pure benzene, for example, oxidizes in the body to produce an epoxide, benzene oxide, which is not excreted readily and can interact with DNA to produce harmful mutations. [edit]Summary According to the Agency for Toxic Substances and Disease Registry (ATSDR) (2007), benzene is both an anthropogenically produced and naturally occurring chemical from processes that include: volcanic eruptions, wild fires, synthesis of chemicals such as phenol, production of synthetic fibers, and fabrication of rubbers, lubricants, pesticides, medications, and dyes. The major sources of benzene exposure are tobacco smoke, automobile service stations, exhaust from motor vehicles, and industrial emissions; however, ingestion and dermal absorption of benzene can also occur through contact with contaminated water. Benzene is hepatically metabolized and excreted in the urine. Measurement of air and water levels of benzene is accomplished through collection via activated charcoal tubes, which are then analyzed with a gas chromatograph. The measurement of benzene in humans can be accomplished via urine, blood, and breath tests; however, all of these have their limitations because benzene is rapidly metabolized in the human body into by-products called metabolites.[79] OSHA regulates levels of benzene in the workplace.[80] The maximum allowable amount of benzene in workroom air during an 8-hour workday, 40-hour workweek is 1 ppm. Because benzene can cause cancer, NIOSH recommends that all workers wear special breathing equipment when they are likely to be exposed to benzene at levels exceeding the recommended

      Reply
      1. peanutbutter

        Benzine is another name for petroleum ether. This is not benzene. primary components of the fraction being pentane and hexane. The ratio of the two determine the rating of the ether. 40-60, 60-80 ratings are based on bp. http://en.wikipedia.org/wiki/Petroleum_ether

        Reply
        1. skunkpharmresearch

          Simple alkanes like pentane and hexane are the prefered mix for our use, but the boiling point range allows some manufactures to add more complex aromatic alkenes, that boil within the same range. It is critical that you review the individual manufacturers MSDS if you are relying on a naphtha designation, as opposed to pentane and hexane. GW

          Reply
  19. scubadoo

    I have made 3 batches using pure Naptha & was very successful. My latest batch was made with ISO 99% available from Costco & seems equally as good however my wife hasn't tried it yet as she still has some Naptha produced oil to finish first. I usually smoke a joint of the oil to test potency & the potency is there with either process i have used. Rick Simpson does say that his solvent of choice is Ether then Naptha, then ISO but does go on to say that either does the job. The problem i found is trying to find pure Naptha. Only 1 store in my town carries it but they have been out for over a month now. The only difference with the finished products is that the oil i did with ISO is darker in color, not as gold in color but that's because ISO draws from the chlorophyll of the plant unlike Naptha. BHO oil does not heat the oil to a decarboxilation temp so i'm not sure how good it would be as a medicine because the process is usually done with a honeybee extractor or home made extractor. It is unfortunate the gov't doesn't recognize the potential of this oil & research it further so we can fine tune the medicinal values of each strain of hemp. Like i said earlier the oil works absolutely as that's why my wife is still alive today & doing well. The oncologists are baffled as they deemed her cancer uncurable(non small cell lung cancer stage 4 Edemo Carcinoma)metastasised in both lungs & liver. Last week's cat scan revealed shrinkage in her tumors & lower cancer blood counts. I was a little skeptical at first about this as you would think that if there's a cure for cancer out there, we would know about it right?? But wow did this ever open up my eyes to what the real medical system agenda is all about...

    Reply
    1. skunkpharmresearch

      There is no doubt that you can do a pristine extraction using Naphtha, but define Naphtha? The word Naphtha is an ancient word and currently means a mixture of those hydrocarbon molecules that boil between 30C and 200C. Even if you add the word Light, before the word Naphtha, it still only means molecules that boil between 30C and 90C. Ostensibly that is molecules with 5 or 6 carbons in the chain, like the simple alkanes n-Pentane and n-Hexane, but it doesn't specify them and leaves open to interpretation what those hydrocarbons are. If you Google Light Naphtha MSDS, you will note that the contents vary considerably from manufacturer to manufacturer, and some of the 5 and 6 carbon chains used are known carcinogens. If you want to do a 5 or 6 carbon chain solvent extraction, it is easy to obtain HPLC grades of Pentane and Hexane, which are simple alkanes, that do exactly what Light Naphtha made without the carcinogens does. We in fact use HPLC n-Hexane for that purpose.

      Reply
  20. scubadoo

    Yes you can but a coffee warmer won't get hot enough to decarb your oil if that's what you're trying to do. As far as the diarrhea goes, with my personal experience, the oil will cause that. I have done different batches of oil with different strains & all have a different result as far as diarrhea is concerned. My wife's been on it for 3 months now & her stage 4 cancer is receding when she was given 3 - 6 months to live 3 months ago,so hang in there with the oil as it does work. The diet change when you have cancer will contribute to the diarrhea as well. People don't expect the oil to taste that bad when ingesting, but the fact of the matter is it tastes terrible but that's normal as long as you don't taste the solvent used to make the oil. Phoenixtears.ca Rick Simpson's website has all the info on this the making of the oil & other info on the subject. Also the youtube video "Run From The Cure" must be seen.

    Reply
    1. skunkpharmresearch

      Thanks for sharing SD! What I've found, is my own patients stopped having digestive tract upset when I stopped using processes that concentrated the chlorophyll in the product. Other's patients have also come to us for relief, after the Iso refluxed oil they were given gave them cramps and diarrhea. Washing that oil in hexane and brine to remove the chlorophyll relieved their symptoms, though most of the oil was lost in the process. None of those patients subsequently reacted to our BHOAA, or QWET oil extractions, so you can see why I might have come to feel the way I do. Of note, is that not everyone taking the offending suppliers oil had digestive upset and a number report symptom relief. For those that did however, it was bad enough to be a deal breaker. Good point on a new diet or cancer giving patients diarrhea, but that wasn't the case with most of the patients in question. Good point on Rick Simpson as well! Everyone interested in the MMJ movement, should familiarize themselves with Rick Simpson and Phoenix Tears. Few folks have put as much effort into the movement than he has, and he deserves recognition for the good that he has done. Like any other site, including this one, I recommend taking what you can use and ignoring the rest. I for instance agree in general with Rick, but not his choice of solvents, or process. If he would change his specification to Hexane or Pentane, instead of light Naphtha, we would be mostly in harmony, but he currently states that his method is the only way. That appears to be a departure from his earlier statements that the processes that he presented were simply ones that almost anyone could do, and which were effective enough. The fish trap exists only because of the fish, and if you get the fish, what does the design of the fish trap matter? I judge the effectiveness of a process, by whether or not the goals were achieved, one of which is to not introduce any uncontrolled variables that can affect quality. Variables like the different mixtures of solvents found in various manufacturers light naphtha recipes, some of which are on health watch lists.

      Reply
  21. rc

    followed ricks instructions as best i could, but my patient has had a bad case of diarrhea since starting the oil.[around 4 weeks].also changed diet to all organic juicing.So not sure if thats contributing to the problem.My question is,can i safely squeeze my remaining oil back into the stainless steal cup and reheat on the coffee warmer with out doing it any harm?

    Reply
    1. skunkpharmresearch

      Concentrated chlorophyll is the single greatest reason that we continue to get other oil producers patients with severe gastric upset. While salubrious in normal concentrations, upset from concentrate OD has been common in these parts. Yes, but keep the temperatures low as decarboxylation and THC evolution to CBN is a time at temperature thang.

      Reply
  22. greenpassion420

    hey there GW, been following a lot of your stuff lately, very new to the oil field, but planning on lovin it! anyway, im wondering if instead of an oil bath, you could instead use sand? i read on another sight about it and it seemed legit. they weren't using it for decarbing our precious oil, but im wondering if it will have the same effect? i ws thinking, just dump some sand in an electric griddle or similar, heat it to the same temps and run everything the same, only difference is sand instead of water. does this sound tangible?

    Reply
    1. greenpassion420

      here's a link to the discussion on it, if links aren't allowed, very sorry, simply remove! http://www.shroomery.org/forums/showflat.php/Number/14337057

      Reply       Edit
    1. skunkpharmresearch

      Usually not, because when we use a thermos to extract, we are planning to use the oil for vaporization. Oil will extract faster after decarboxylation, if you use a non polar solvent, because carboxylic acid forms are polar.

      Reply
          1. skunkpharmresearch

            If you wish to decarboxylate plant material, I would put it in a very thin layer on a cookie sheet, and place it in an oven stabalized at 250F for 27 minutes. Decarboxylation will improve the extraction efficiency using non polar solvents, though butter and some oils like coconut oil, still have a lot of polar water in them, so the effect is not huge. GW

            Reply
        1. skunkpharmresearch

          We decarboxylate all of our oral potions, but we decarboxylate our oils after extraction, because it is easier to tell precisely where we are with regard to decarboxylation, by watching the bubbles. GW

          Reply
          1. maxx

            thank you for all the answers your great. one more lol could you soak the plant material in water to get rid of the more polar soluble properties? would that make the thc stronger or more easily extracted once the plant material has dried out?

            Reply
            1. skunkpharmresearch

              There are water wash techniques that do just that, and do produce a milder smoke, but you can't handle plant material without losing trichomes, so you would have to do it using filters to recover them, or they would be lost. It wouldn't make the THC stronger and would most likely reduce the overall yield. It would reduce the amount of chlorophyll available for the alcohol to dissolve, but there would still be lots left, so there wounldn't be much advantage that I can see. It is easy enough to use a technique that controls chlorophyll pickup extracting with a polar solvent like alcohol, or you can use a non polar solvent like butane or hexane, to mostly sidestep the issue all together.

          2. maxx

            what would be the perfect time and temp to extract the plant material to coconut oil? for both decarboxylated and un-decarboxylated plant material before extraction

            Reply
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