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.]

No, this is not a problem. Your liver naturally produces Acetone when breaking down lipids which you burn as energy or is eliminated through urine or exhaling. Here is what ChatGPT says about Keytones: 

"Ketones are a type of molecule that are produced by the liver when the body is low on glucose (sugar) and needs an alternative source of energy. The body can use ketones for energy when glucose is not readily available, such as during periods of fasting, low carbohydrate diets, or intense exercise.

Ketones can be used as a source of fuel for the brain and other organs in the body, and they can also be converted back into glucose by the liver to provide energy for the body's cells. This process is called gluconeogenesis.

In addition to their role in energy metabolism, ketones also have other potential benefits. For example, they may help to reduce inflammation in the body and improve cognitive function. Some studies have suggested that following a ketogenic diet, which is high in fat and low in carbohydrates, may have therapeutic benefits for certain medical conditions, such as epilepsy, type 2 diabetes, and certain types of cancer.

However, it is important to note that the body typically relies on glucose as its primary source of energy, and high levels of ketones in the blood can be a sign of a serious medical condition called diabetic ketoacidosis (DKA) in people with type 1 diabetes. As with any dietary or medical intervention, it is important to consult with a healthcare provider before making any changes to your diet or lifestyle."

Here is an exhaustive discussion published by the British Government on the effects of Acetone in the body.

Definitely not! Though it's not cancerous like Benzene or toxic like Methanol, it still is very harsh in the body even in low quantities. Its not a drink, its a solvent. If it trickles down your throat, it can hurt you. Don't do that!

 At drinking volumes, Isopropyl will get you more inebriated than Ethanol with much more discomfort and pain. Every health clinic around the world has an Isopropyl Overdose protocol because this is a world wide problem. But down at the molecular level interesting enough, in trace quantities, the tables turn. Your liver breaks down Ethanol into Acetaldehyde, which after much exposure, will cause DNA damage. On the other hand, Isopropyl is broken down into Acetone and expelled through urine and exhaling. Did you know your body creates Acetone when your liver breaks down lipids? Your body knows how to deal with these trace quantities through natural metabolism. This is why making RSO with Isopropyl is safe in oil. You don't want to make a tincture out of Isopropyl, but there's no chance Isopropyl will hurt you with residual trace quantities. There is nothing even remotely dangerous with trace quantities of Isopropyl in RSO. This is why the State of Oregon has legalized Isopropyl as a solvent in making Cannabis extract.

Here is the NIH on medical training of Isopropyl Toxicity from a health care perspective. 

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 Reagent Grade’ at the top. The bottles of Isopropyl Alcohol found at the neighborhood store are Technical Grade. Take a look at the grading system. For the consumer at home making RSO, the USP-NF and higher grades are guaranteed safe within the limits of the FDA exposure guidelines. 

TITLE 21--FOOD AND DRUGS

CHAPTER I--FOOD AND DRUG ADMINISTRATION

DEPARTMENT OF HEALTH AND HUMAN SERVICES

SUBCHAPTER B - FOOD FOR HUMAN CONSUMPTION (CONTINUED)

PART 173 -- SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION

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.

"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.

"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.

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.

Here is Colorado's Marijuana Enforcement Dividsion code 5-315 section A.2 – Permitted Categories of Medical Marijuana Concentrate Production.

"A Medical Marijuana Products Manufacturer may also produce Solvent-Based Medical Marijuana Concentrate using only the following solvents: butane, propane, CO2, ethanol, isopropanol, acetone, heptane, ethyl acetate, and pentane. The use of any other solvent is expressly prohibited unless it is approved by the Division."

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 polar compounds dissolved into your oil.  

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.

3. Isopropyl has a magic power with table salt (This was used in RSO 2.0, not in RxCE).

• 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 opened 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.  

I asked ChatGPT..

"The claim that 100% isopropyl will leave behind hydroxyl groups that are difficult to purge due to their bond to the oils is not accurate. Isopropyl alcohol (isopropanol) is a widely used solvent in various industries, including extraction processes. It is known for its ability to dissolve oils, resins, and other organic compounds effectively.

Isopropyl alcohol is a polar solvent, meaning it can break down polar substances like water and other hydrophilic compounds. It can also dissolve non-polar substances like oils and fats. During the extraction process, isopropyl alcohol can dissolve the desired oils, including cannabinoids, from the plant material.

However, it's important to note that thorough purging is necessary to remove any residual solvent and ensure a clean final product. Purging involves removing the solvent through evaporation or other methods to leave behind the desired compounds. The presence of hydroxyl groups or any other unwanted residues would depend on the quality of the extraction and the purging process, rather than the use of 100% isopropyl alcohol itself.

To achieve a high-quality extract, it's crucial to follow proper extraction and purification techniques, which may involve additional steps such as winterization, filtration, or vacuum drying. These methods help eliminate impurities and unwanted substances, ensuring a purer final product."