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Cannabis Extraction Solvent Safety – An Evidence Based Review

Introduction

1. OPENING STATEMENT

3. UNDERSTANDING DRINKING VS TRACE QUANTITIES

2. METABOLISM OF SOLVENTS

4. RELEVANT MEDICAL ISSUES

5. WHICH SOLVENTS ARE SAFE AT HOME

6. WHAT PROCESSES ARE SAFE TO MAKE OIL AT HOME

7. VAPOR DANGERS WHILE SAFELY MAKING OIL AT HOME

8. CONCLUSION

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Cannabis Extraction Solvent Safety – An Evidence Based Review

1. Opening Statement

The World Health Organization says there is “No level of alcohol consumption is safe for our health

Consumers ignore the significance of ethanol’s chemistry and the long term effects. Today, we will -

See Alcohol for what it is - a solvent

Learn each solvent’s Metabolic Pathways through the

liver & kidneys

See the difference between drinkable quantities and

residual traces through illustrated numbers

List possible health issues around residual solvents

Expand the knowledge of safely making oil at home

See how fast dangerous levels of solvent vapors

are generated during distillation

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Cannabis Extraction Solvent Safety – An Evidence Based Review

2. METABOLISM OF SOLVENTS

Review of Alcohol Metabolism

The liver metabolizes approximately 8g (+-2g) of ethanol per hour.

One ounce of 80 proof vodka has approximately 9g of Ethanol.

Ethanol Acetaldehyde

-> ->

CH3-CH2-OH CHO-CH3

Ethanol metabolizes into Acetaldehyde.

Acetaldehyde is both genotoxic, carcinogenic, and teratogenic, with Long term exposure

leading to Alcoholic Liver Disease, Cirrhosis of the liver, Cancer, Birth defects and more

Ethyl Acetate metabolizes into Ethanol thus shares this metabolic pathway.

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Cannabis Extraction Solvent Safety – An Evidence Based Review

2. METABOLISM OF SOLVENTS

Review of Alcohol Metabolism

Acetone, a ketone, is not broken down as it’s bio-friendly as-is, up to PDE levels.

Isopropyl metabolizes into Acetone thus shares Acetone’s metabolic pathway.

Isopropyl Acetone

-> ->

CH3-CHOH-CH3 CH3-2CO-CH3

Acetone is neither genotoxic, carcinogenic, or teratogenic. The Liver produces Acetone

ketones when breaking down fats. Acetone is used as an energy source during a low

carb state. Diabetic state of Ketosis has elevated acetone levels in the breath. Service

Dogs for diabetics trigger low sugar level alerts by smelling acetone.

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Cannabis Extraction Solvent Safety – An Evidence Based Review

3. UNDERSTANDING DRINKING VS TRACE QUANTITIES

Ethanol 3 Y 166.7mg 7.9g 336.1g 24.3 Y Y

*1 Partial GRAS rating for use in food

*2 FDA has published Acetone’s PDE to be higher than Ethanol’s PDE

*3 LD50 is an approximation based on rat studies and varies across Safety Data Sheets. 105lbs is 47.62kg

*4 Permanent visual damage may occur with minimum ingestion of 30 mL of methanol

Solvent Chemical Properties as Liquid

Ethyl Acetate 3 Y*1 117.0mg 5.5g 538.1g 6.0 N N

Acetone 3 Y*1 210.0mg*2 10.0g 276.1g 20.7 Y Y

Isopropyl 3 Y*1 138.0mg 6.5g 238.1g 18.2 Y Y

Methanol 2 N 30.0mg*3 6.5g 30.0g*4 32.7 N Y

Benzene 1 N 1.0mg 0.05g 157.4g 2.17 Y Y

Pentane 3 N 604.6mg 28.7g 276.1g 1.8 Y Y

Heptane 3 N 840.0mg 40.0g 238.1g 1.9 Y Y

Chem FDA GRAS FDA PDE FDA PDE LD50*3 Dialetric Forms Miscible

Name Class Rated mg/kg/day g/105lbs g/105lbs Constant Azeotrope w/water

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Cannabis Extraction Solvent Safety – An Evidence Based Review

3. UNDERSTANDING DRINKING VS TRACE QUANTITIES

How much is too much? The Solvent’s LD50 for a 105 lbs person

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Cannabis Extraction Solvent Safety – An Evidence Based Review

3. UNDERSTANDING DRINKING VS TRACE QUANTITIES

A: FDA allows 0.5% so 10mg * 0.5 = 0.05mg

A gummy weighing 4 grams..

has 10mg THC/CBD..

..with 0.5% solvent, which is 0.05ug

Permitted Daily Exposure (PDE) amount for a 105 lbs person in grams scaled to show micrograms.

Residual Solvent in 10mg = 50ug = 0.000.050ug

Acetone:........210.0 mg/kg/day = 9.996.000ug

Ethanol:........166.7 mg/kg/day = 7.901.000ug

Isopropyl:......138.0 mg/kg/day = 6.568.000ug

Ethyl Acetate:..117.0 mg/kg/day = 5.569.000ug

Heavier persons will have higher PDEs

The 10mg may safely contain up to 0.5% (0.05mg) residual solvent. This is well within the FDA’s PDE for all four solvents.

Q: How much solvent is in a 10mg gummy?

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Cannabis Extraction Solvent Safety – An Evidence Based Review

3. UNDERSTANDING DRINKING VS TRACE QUANTITIES

Ethanol’s Permitted Daily Exposure (PDE) limit for a 105 lbs person is 7.9g over 24 hours.

Ethanol PDE:...166.7 mg/kg/day = 7,901,000 ug

/ 24

Milligrams per hour = 329,208 ug

Residual solvent amount / 50 ug

=============

Gummies to be eaten every hour: 6,584

Q: How many 10mg gummies does it take

To reach the PDE’s 24hr limit?

A: 6,584 10mg gummies per Hour x 24 hrs!

(equivalent to 65 grams of Cannabis oil)

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Cannabis Extraction Solvent Safety – An Evidence Based Review

4. RELEVANT MEDICAL ISSUES SURROUNDING SOLVENTS

Primarily Concern is Impaired Liver and Kidney Dysfunction

Some conditions of concern exist around solvents and chemicals in general. Patients

with these conditions are highly encourage to discuss these issues with a toxicologist.

CKD – Chronic Kidney Disease

Very prevalent with at least 1/3rd of 65 yo+ adults have some stage of CKD

DKA - Diabetic Ketoacidosis

CI – Chemical Intolerances specific to solvents

MCAS – A Premature early response to low dose chemicals by degranulation

Related to COVID cytokine storms

Chemical Intolerance and Mast Cell Activation - A Suspicious Synchronicity

MCS – Environmentally Caused Multiple Chemical Sensitivities

Allergies to Organic Solvents

Very rare because our bodies produce alcohols and acetone

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Cannabis Extraction Solvent Safety – An Evidence Based Review

5. WHICH SOLVENTS ARE SAFE AT HOME

FDA QC3 Classifies solvents by harmfulness

A lot of Solvents are permitted for cannabis extraction, not all safe for home use.

Class 1 Cancerous - Not permitted, period

Rabbit Hole: Benzene is a byproduct of terpene combustion

Class 2 Toxic – Poisonous solvents, permitted for used by industrial processors, not for home

Hexane, Xylene, Methanol, Toluene

Class 3 Relatively safe solvents due to low toxicity

Acetone, Ethanol, Ethyl Acetate, Isopropyl Alcohol - all class 3 and found in the home

Pentane and Heptane are class 3 but hydrocarbon based.

“It is considered that amounts of these residual solvents of 50 mg per day or less (corresponding to 5,000 ppm or 0.5 percent under Option 1) would be acceptable without justification.”

Gas extraction via Butane, Propane, C02 are restricted from home use

Not legal at home, only in licensed facilities

Requires additional hardware and training

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5. WHICH SOLVENTS ARE SAFE AT HOME

What is the best solvent for Cannabis Extraction?

All 4 are found in every-day used products within the home - Distilled spirits, wine,

hand gel, and fingernail polish remover

All 4 have FDA GRAS or Conditional GRAS Classifications

Name Pros Cons

EtOH Full GRAS Expensive due to taxes

EtAC least Polar(6.02dc) dissociates in water, most expensive

Ace Most bio friendly Lowest Flash/Boiling points

IPA ~Same as Acetone with

Flash/Boiling points

Same as EtOH, but less

polar

And the recommended solvent is..

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Cannabis Extraction Solvent Safety – An Evidence Based Review

5. WHICH SOLVENTS ARE SAFE AT HOME

What is the best solvent for Cannabis Extraction?

All 4 are found in every-day used products within the home - Distilled spirits, wine,

hand gel, and fingernail polish remover

All 4 have FDA GRAS or Conditional GRAS Classifications

Name Pros Cons

EtOH Full GRAS Expensive due to taxes

EtAC least Polar(6.02dc) dissociates in water, most expensive

Ace Most bio friendly Lowest Flash/Boiling points

IPA ~Same as Acetone with

Flash/Boiling points

Same as EtOH, but less

polar

And the recommended solvent is Isopropyl Alcohol

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Cannabis Extraction Solvent Safety – An Evidence Based Review

5. WHICH SOLVENTS ARE SAFE AT HOME

Isopropyl Alcohol is recommended for these reasons:

  • You are never going to encounter harmful levels in properly made oil as trace levels will be well under the FDA’s Permitted Daily Exposure value

  • Trace levels are safe as the body will metabolize it into Acetone, a ketone which is used as an energy source (See toxicology)

  • USP/NF grades available at nearly 1/4th the price of ethanol

  • One study shows isopropyl alcohol will extract more cannabinoids than ethanol

  • Easy as Ethanol to remove and recover through distillation

  • Permitted for cannabis extraction in most states that have legalized medical cannabis

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Cannabis Extraction Solvent Safety – An Evidence Based Review

5. WHICH SOLVENTS ARE SAFE AT HOME

Guidelines for Purchasing Solvents at Retail

Must have Full or Conditional GRAS approval

Always use USP-NF and higher grades, never denatured

At Retail today

This USP/NF grade 99% Isopropyl is available at nearly 1/4th the price of Ethanol.

Extractohol claims to be pure without denaturants

710 Spirits is denatured with Heptane, requires special handling to remove Heptane

There are other non-denatured ethanol products available from this mfg

Current Suppliers for consumers

Liquor stores

Amazon

BVV

American-ethanol.com

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Cannabis Extraction Solvent Safety – An Evidence Based Review

6. WHAT PROCESSES ARE SAFE TO MAKE OIL AT HOME

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Cannabis Extraction Solvent Safety – An Evidence Based Review

6. WHAT PROCESSES ARE SAFE TO MAKE OIL AT HOME

Refine x Cannabis Extract published in March 2023

RxCE is the ‘Poor Man’s Distillate’ with Concentration reaching 80% Total Cannabinoids

Reorders the QWET process to optimize extraction time

Introduces a robust purge of solvents with a two pass approach

1st pass for the bulk extraction and reduction to oil

2nd pass to winterize then reduce to final oil

2nd pass ends by decarbing at 250f presenting virtual firewall to residual solvents

Is ‘Solvent Agnostic’ meaning you can use any of these 4 solvents in either pass

Uses only Kitchen Gear, no vacuum pumps or lab gear

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Cannabis Extraction Solvent Safety – An Evidence Based Review

6. WHAT PROCESSES ARE SAFE TO MAKE OIL AT HOME

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Cannabis Extraction Solvent Safety – An Evidence Based Review

7. VAPOR DANGERS WHILE SAFELY MAKING OIL AT HOME

Safety First!

  • Do not boil off alcohol near open flame, furnaces, cigarettes, furnaces or sparks as the vapors are very flammable

  • Always boil off alcohol in well ventilated spaces with active airflow to quickly dissipate the fumes

  • It is highly recommend to use a Moonshine still or Water Distiller for alcohol recovery. This will avoid high concentration of vapors

  • Use gloves to protect against skin contact with the solvent

  • Check local and State laws for permitted solvents

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Cannabis Extraction Solvent Safety – An Evidence Based Review

7. VAPOR DANGERS WHILE SAFELY MAKING OIL AT HOME

Ethanol 1000ppm -114c/-173f 12c/55f 78c/173f 40mmHg 363c/785f

Solvent Chemical Properties as Gas

Ethyl Acetate 400ppm -83c/-118f -4c/24f 77c/170f 73mmHg 427c/800f

Acetone 1000ppm -94c/-137f -11c/0f 56c/133f 180mmHg 465c/869f

Isopropyl 400ppm -89c/-127f 11c/53f 78c/180f 33mmHg 399c/750f

Methanol 200ppm -62c/-144f 9c/49f 65c/149f 96mmHg 464c/867f

Benzene 1ppm 5c/41f -11c/12f 80c/173f 60mmHg 498c/928f

Pentane 1000ppm -129c/-202f -18c/57f 36c/97f 420mmHg 260c/500f

Heptane 500ppm -90c/-131f -3c/25f 98c/209f 37mmHg 285c/433f

Chem PEL Melting Flash Boiling Vapor Auto

Name (ppm) Point Point Point Pressure Ignite

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Cannabis Extraction Solvent Safety – An Evidence Based Review

7. VAPOR DANGERS WHILE SAFELY MAKING OIL AT HOME

Greatest Danger: Vapor Concentrations Can Quickly Exceed Safe Levels. Alcohol recovery is highly recommended to recapture vapors

Table: Converting 1 Liter Liquid to Vapor

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Cannabis Extraction Solvent Safety – An Evidence Based Review

8. CONCLUSION

Here we’ve looked at four different solvents commonly found in the home. From a chemistry and biological perspective, these four represent the safest solvents that can be used without requiring special training or lab gear. This data reflects the current knowledge of the world medical community and might change in the future. A lot of the in-vivo solvent testing was on lab animals then extrapolated to human scale. These numbers may change with additional research.

On the consumer side, due to lack of in-depth understanding of chemistry, consumers believe that ethanol is the safest because it can be ingested. This seemingly logical conclusion permits users to disregard the dangers of long term exposures leading to cirrhosis of the liver, birth defects and DNA damage.

As shown in this discussion, the most feared solvents, acetone and isopropyl, viewed as poison at any level, are actually the least biologically harmful to the human body down at the trace level. By understanding these solvents at the molecular level and following through the metabolic pathways, the picture becomes clear. The most bio-friendly solvent is Acetone, being the least toxic of all 4 solvents at trace levels.

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Cannabis Extraction Solvent Safety – An Evidence Based Review

8. CONCLUSION

This fact is supported by the FDA establishing higher Permitted Daily Exposures for Acetone versus Ethanol. This is significant because the definition of PDE draws a line in the sand between harmless and harmful levels.

For virtually the entire world, the debate on Ethanol vs Isopropyl safety is actually a mute point because residual traces of these FDA Class 3 solvents are low enough to be safely metabolized by healthy liver and kidneys. When in compliance with regulations, residual solvents in edibles has been shown to be orders of magnitude under the FDA Permitted Daily limits.

Bringing it home:

  • Permitted Daily Exposure (PDE) is the dividing line between trace levels and drinking levels.
  • You are never going to encounter drinking quantities of solvents by ingesting edibles.
  • Drinking exposures are often over PDE values. One shot of 80 proof Vodka has 9.4 grams ethanol, more than the PDE for a 105lbs person.
  • Traces of solvent in edibles are orders of magnitude below the EPA’s PDE values.

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Cannabis Extraction Solvent Safety – An Evidence Based Review

8. CONCLUSION

In closing, when permitted by local laws, medical patients at home have good options for solvent selection. Some Chemical-Intolerant health issues might preclude certain solvents based individual sensitivities. Those suffering from impaired liver or kidney function may now choose which solvent best fit their chemical sensitivity. This premise needs to be discussed with medical professionals experts in the field of Toxicology.

Link to all references

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Cannabis Extraction Solvent Safety – An Evidence Based Review

Definitions

Glossary of Definitions Given by Many Gov’t Agencies (EPA,FDA,CDC,etc)

PDE Permitted Daily Exposure values are calculated based on NOAEL & LOAEL

NOAEL / LOAEL physical measurements - For in-vivo Bioanalytical chemistry measurements

NOAEL No Observable Adverse Effects Level - Limit of detectability. Undetectable below this level

LOAEL Lowest Observable Adverse Effects Level -

The highest dose level that does not produce a significant increase in adverse effects

LOD / LOQ theoretical measurements - For in-vitro Analytical Chemistry modeling - Theoretical LOAEL/NOAEL

LOD Limit of Detection noise floor - Less reliable. Can't always be measured

LOQ Limit of Quantification - More reliable. Consistently measurable

LD50 Lethal Dose for 50% of those affected

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Cannabis Extraction Solvent Safety – An Evidence Based Review

Definitions

OSHA Definitions for Airborne hazzards

PEL Permitted Exposure Limit of chemical exposure of airborne contaminants

For vapor fire hazards

LEL Lowest Explosive Limit - The National Fire Protection Agency (NFPA)

UEL Upper Explosive Limit - The National Fire Protection Agency (NFPA)

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Cannabis Extraction Solvent Safety – An Evidence Based Review

All following slides are my ‘sandbox’ for working pages

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Cannabis Extraction Solvent Safety – An Evidence Based Review

1. Opening Statement & Definitions

Today’s Talk Will Center on These Four Solvents:

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Cannabis Extraction Solvent Safety – An Evidence Based Review

5. WHICH SOLVENTS ARE SAFE AT HOME

These solvents can be grouped into 2 sets based on Metabolism

Group 1 based on Ethanol:

Ethanol, today’s consumer defacto choice by consumers

Has FDA’s Full GRAS rating

Beer, wine, distilled spirits, food flavoring ‘tincture’

Ethyl Acetate, Heavier brother to ethanol

Ethyl Acetate is an ester of Ethanol (Ethanol + Acetic Acid = Ethyl Acetate)

Behind the curtain: in wine, used to make decaf coffee

Least polar of the 4 with a Dialetric Constant of 6.02

Has an FDA Conditional-GRAS rating

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Cannabis Extraction Solvent Safety – An Evidence Based Review

5. WHICH SOLVENTS ARE SAFE AT HOME

These solvents can be grouped into 2 sets based on Metabolism

Group 2 based on Acetone:

Acetone – An organic non-toxic molecule produced by your liver, the simplest ketone

Has a higher PDE than Ethanol!

Has an FDA Semi-GRAS rating

Technical grade used as Finger Nail Polish Remover

Acetone Vs Alcohol (EtOH): What Are The Differences

One of the biggest differences between these compounds is that acetone is

organic and non-toxic whereas alcohol is ethanol-based making it poisonous.”

Isopropyl Alcohol - A molecule that can be generated by the human body.

20% less polar than ethanol. (Dialetric Constant of 18.2 vs 24.3)

Has an FDA Semi-GRAS rating for food additives

Used in Rubbing Alcohol, hand sanitizer, and other cleaning agents