Using Isopropyl Alcohol

Use Isopropyl to Safely Make RSO? Yes You Can!

Isopropyl Alcohol has a much maligned reputation for being dangerously toxic and at worst, cancerous. In all controversies, there are facts and there are opinions. Its the muddled in-between ground that has become a vortex of misinformation. First, here are the facts about Isopropyl Alcohol. Knowing these facts will help frame the discussion around safely using Isopropyl to make RSO. The safe use of Isopropyl has been a priority when developing the RSO 2.0 process found on this website. Basic summary - If you don't drink it, nor bathe in it, it will not hurt you.

The following statements are quotes from official documents found on the U.S. Food and Drug Administration website, the U.S. National Institute of Health, Oregon State website, and other sources.

Isopropyl Alcohol, a.k.a., 2-Propanol, is an organic molecule with the formula of C3H8O. It is important to differentiate between Isopropyl and other products known as rubbing alcohol. Too often these two products are considered the same thing. Rubbing alcohol is a product name that typically contain other compounds such as oils, perfumes and colors.

Isopropyl is manufactured through means of a chemical reaction; whereas, Ethanol is created as the waste product of yeast. Yeast eats sugar, farts C02 and pisses alcohol. Isopropyl comes together something like Milton The Monster. Nice picture, huh?

[BTW, you may encounter 1-Propanol on the FDA website. 1-Propanol is not Isopropyl Alcohol. It has the same set of atoms, but assembled into a different molecule, having different chemical characteristics. It's so different, it has a completely different manufacturing process. As a result, 1-Propanol is never sold under the name of Isopropyl Alcohol. The two are not interchangeable. The FDA has not approved 1-Propanol for food or topical applications, it has other uses.]

What is the benefit of using Isopropyl over Ethanol for making oil?

Isopropyl chemical properties are slightly different than Ethanol with these benefits:

  1. Isopropyl is 20% less polar than Ethanol. This directly translates into 20% less unwanted compounds dissolved out of the plant.

  2. Isopropyl is much faster in dissolving oils. The faster the extraction time, the less time is given to pull unwanted compounds.

  • Isopropyl can remove 80% of the oils in 20 seconds at room temperature.

  • Ethanol needs 3 minutes to accomplish the same thing, same temperature rules apply, but can only cool down to 50c/-58f

  1. Isopropyl has a magic power with table salt that Ethanol does not.

  • Adding table salt to Isopropyl separates the alcohol from water. Isopropyl forms the top layer, water forms the bottom. This is known as "Salting Out". Ethanol requires Potassium Carbonate to accomplish this, but it radically changes the water's pH which affects the Cannabinoids so don't do this.

  • "Salting Out" Isopropyl opens a new door to cleaner oil with the discovery of Brine Isopropyl Degumming. BID removes semi-polar phospholipids which bind water soluble compounds into your oil.

  • Distilling temperatures can run as low as 82c/180f up 100c/212f. To save the acidic state (CBDA vs CBD), you must distill at the lower temperature. At 82c/180f, it takes 10 hours to decarb.

FDA has approved the use of Isopropyl in certain food ingredients. This means the FDA approves traces amounts for human consumption. This is how Parts Per Million playout in our daily lives. More below..






Subpart C - Solvents, Lubricants, Release Agents and Related Substances

Sec. 173.240 Isopropyl alcohol.

Isopropyl alcohol may be present in the following foods under the conditions specified:

(a) In spice oleoresins as a residue from the extraction of spice, at a level not to exceed 50 parts per million.

(b) In lemon oil as a residue in production of the oil, at a level not to exceed 6 parts per million.

(c) In hops extract as a residue from the extraction of hops at a level not to exceed 2.0 percent by weight: Provided, That,

(1) The hops extract is added to the wort before or during cooking in the manufacture of beer.

(2) The label of the hops extract specifies the presence of the isopropyl alcohol and provides for the use of the hops extract only as prescribed by paragraph (c)(1) of this section.

FDA has approved Isopropyl for topical use on the human body.

"The only active ingredients used in OTC consumer antiseptic rub products that are eligible for consideration under the OTC Drug Review are ethyl alcohol (referred to subsequently as alcohol), isopropyl alcohol, and benzalkonium chloride."

Isopropyl is widely available in consumer products and is the primary antimicrobial found in many rubbing alcohol products, hand wipes, hand sanitizer sprays and gels. The CDC says that a minimum of 60% alcohol in hand sanitizer is required for effective use against COVID19.

FDA classifies solvents into three classes. Benzene in Class1, Methanol in Class 2, with Ethanol and Isopropyl (2-Propanol) in Class 3. Here's why that is so significant..

"Solvents in Class 1 (Table 1) should not be employed in the manufacture of drug substances, excipients, and drug products because of their unacceptable toxicity or their deleterious environmental effect.".

"Solvents in Class 2 (Table 2) should be limited in pharmaceutical products because of their inherent toxicity.".

"Solvents in Class 3 (Table 3) may be regarded as less toxic and of lower risk to human health. Class 3 includes no solvent known as a human health hazard at levels normally accepted in pharmaceuticals.".

Benzene is a Class 1 solvent known to cause cancer. Proctor & Gamble has had many public product recalls in the Fall of 2021 due to residual amounts of Benzene in consumer hair care and skin products.

Methanol is a Class 2 solvent known for its toxicity and for making people go blind. The FDA has published a list of banned hand sanitizers found to contain methanol.

Both Ethanol and Isopropyl are Class 3 solvents with low risk to human health. But only Ethanol is considered GRAS (Generally Recognized as Safe) for human consumption. Isopropyl is approved only in trace amounts, as seen above. Its not something you should drink as it causes major gastric problems.

The State of Oregon approves Isopropyl as a solvent for Cannabis extraction.

In section OAR 845-025-3260 Cannabinoid Concentrate and Extract Processor Requirements,

(3) Cannabinoid Concentrates. A processor with an endorsement to make cannabinoid concentrates:

(a) May not:

(A) Use denatured alcohol.

(B) If using carbon dioxide, apply high heat or pressure.

(b) Must only use or store dry ice in a well-ventilated room to prevent against the accumulation of dangerous levels of carbon dioxide.

(c) May use:

(A) A mechanical extraction process; or

(B) A chemical extraction process using a nonhydrocarbon-based or other solvent, such as water, vegetable glycerin, vegetable oils, animal fats, isopropyl alcohol or ethanol.

(C) An extraction process using the solvent carbon dioxide, provided that the process does not involve the use of heat over 180 degrees (Fahrenheit) or pressure.

The City of Portland Oregon restates it clearly in 14B.130.020b:

B. “Cannabinoid concentrates” means a substance obtained by separating cannabinoids from marijuana by;

  1. A mechanical extraction process;

  2. A chemical extraction process using a nonhydrocarbon-based or other solvent, such as water, vegetable glycerin, vegetable oils, animal fats, isopropyl alcohol or ethanol;

  3. A chemical extraction process using the solvent carbon dioxide, provided that the process does not involve the use of high heat or pressure; or

  4. Any other process identified by the Oregon Liquor Control Commission or the Oregon Health Authority, by rule.

Your body produces Acetone so residual traces of Isopropyl Alcohol are handled as a normal course of metabolism.

Isopropyl Alcohol breaks down into Acetone in your liver. This is not a problem. Your liver naturally produces Acetone when breaking down lipids which you exhale. Here is an exhaustive discussion published by the British Government on the effects of Acetone in the body.

Can you drink Isopropyl Alcohol?

Definitely not. Though it's not cancerous like Benzene or toxic like Methanol, it still is a bad thing in the body even in low quantities. Here is the NIH on medical training of Isopropyl Toxicity from a health care perspective. Its not a drink, its a solvent. If it trickles down your throat, it can hurt you. Don't do that..

What Isopropyl products are safe to use?

That depends on the application. A grading system has long existed in the chemical industry to designate levels of purity. Ethanol is available in multiple grades and so is Isopropyl alcohol. These grades range from from Technical Grade at the bottom, to ‘ACS Grade’ at the top. The bottles of Isopropyl Alcohol found at the neighborhood store are Technical Grade. For the consumer at home making RSO, the USP-NF and higher grades are guaranteed safe within the limits of the FDA exposure guidelines.

Step into our visual elevator! We have a million floors to descend, all the way down into Parts Per Million.

This illustration shows how Parts Per Million relates to the familiar items in our daily lives. For instance, an average grain of rice is 29mg according to Google. Do you buy Gummi bears at the Dispensary? 10mg is a common dose per bear.

Take a close look at the other sections. The FDA allows certain food ingredients to contain PPM quantities of Isopropyl. The five lab tests presented below all come in under Oregon State's Limit of 5mg. How lethal is Ethanol and Isopropyl? About one cup of Isopropyl or 1.4 cups of Ethanol may be fatal to a 50c/110lb person.

So, how did Isopropyl Alcohol become so maligned in our society?

The answer begins with our parents telling us “Don’t drink that, it's poison!”. That served us well as children, but as adults having access to a world of information at our fingertips, we can easily find the truth. Trace quantities of Isopropyl, a.k.a. 2-Propanol, are broken down and expelled as a normal course of metabolism in the human body with no detrimental effects.

As shown above, the FDA permits Isopropyl in certain spice ingredients to be consumed by humans. Just the mere fact it has FDA approval for limited food uses, says the whole story. Again, in trace amounts, Isopropyl, is tolerated by the human body with no detrimental effects.

Remember, Isopropyl is the normal disinfectant in hand sanitizer, hand wipes, and Rubbing Alcohol. The small amount of Isopropyl that gets absorbed through the skin is metabolized by the liver and expelled when exhaling, with no detrimental effects.

If this were not true, the FDA would not allow it to be in food products. Rest assured, Isopropyl is not cancerous. If it were, it would be a Class 1 solvent. It does not cause blindness like Methanol, or it would be a Class 2 solvent. Isopropyl is listed with Ethanol as a Class 3 solvent "with low toxic potential to humans"

Bringing it Home.

Basic summary on Isopropyl Alcohol's safety - if you don't drink it, nor bathe in it, it will not hurt you. Isopropyl Alcohol is a well known, well understood molecule, almost identical to Ethanol. FDA regulations and guidelines provide safeguards for limited use in food products and topical applications.

Given the great fear that exists about Isopropyl’s toxicity, much time and effort has been spent in creating a robust procedure for eliminating residual Isopropyl from the oil. Heat over time is the catalyst that evaporates Isopropyl from the oil, identical to Ethanol. The final reduction step is a literal firewall against retaining alcohol in the oil. Multiple lab tests are presented below showing undetectable levels of Isopropyl in the RSO created using this process.

Additional Reading:

  1. Isopropyl Alcohol Physical and Chemical Properties published by the U.S. National Institute for Health (

  2. Isopropanol Toxicity published by the U.S. National Institute for Health (

  3. Grades of Chemicals by

  4. Acetone: General Information by GOV.UK

  5. Toxicological Data For Class 3 Solvents published by the FDA

  6. FDA Q3C Q3C — Tables and List, Guidance for Industry

  7. FDA Residual Solvents - USP Chapter 467

  8. NIH Pubmed Safety Data Sheet – Ethanol

  9. NIH Pubmed Safety Data Sheet – Isopropyl Alcohol

  10. Isopropyl ofactory threshold

  11. Industry authority Gray Wolf's post on performing a Quick Wash with Isopropyl (QWISO).

  12. Salting Out Isopropyl to separate the alcohol from the water content.

The following lab test reports are presented in reverse order, with the most recent presented first.

Lab report #5 12/22 - The best Yet! This oil was made using Dry Ice in a QWISO extraction, then Silting, Distillation, Winterization and final Reduction. Total Cannabinoids are at the threshold of Distillates. Residual Solvents are undetectable.

Amazing! 78% Total Cannabinoids which is nearly Distillate Quality.

2-Propanol (IPA) again is undetectable.

Lab report #4 02/22 - Isopropyl Alcohol and Brine Distillation. Residual Solvents are undetectable.

4th lab result during mid development stage. This test was the second to use Brine in the distillation rather than water. Potency is much better!

2-Propanol (IPA) is undetectable.

Lab report #3 09/21 - Isopropyl Alcohol and Brine Distillation.

3rd lab result during mid development stage. This test was the first to use Brine in the distillation rather than water. Potency is much better!

2-Propanol (IPA) is undetectable.

Lab report #2 06-21 - Using Isopropyl Alcohol and water in distillation. Isopropyl is undetectable.

2nd lab result during early development stage. This test used water in the distillation rather than Brine. Potency is getting better!

2-Propanol (IPA) is undetectable.

Lab report #1 05/21 - Using Isopropyl Alcohol and water in distillation. Isopropyl is undetectable.

1st lab result during early development stage. This test used water in the distillation.

2-Propanol (IPA) is undetectable.

Join our Facebook group to discuss all the science around these projects.

Disclaimer: Your use of any information or materials on the C.H.S. Website is entirely at your own risk, for which we shall not be held liable. It shall be your own responsibility to ensure safe use and operation of any processes, products, services or information made available through C.H.S publications and Website.