How To Make 70% Ethanol From 100% Ethanol (200 Proof)

70% ethanol solutions are used in homes for cleaning, for manufacturing medicinal products and in laboratories as chemical reagents. A good recipe for a 70% non-denatured ethanol solution is to blend 70 milliliters of pure ethyl alcohol and 30 milliliters of distilled or DI water (deionized water). This is 100 milliliters of solution which is about 3.4 ounces. You can buy 70% ethanol (140 proof ethyl alcohol) solutions online from companies like Lab Alley. However, it is helpful to know how to make your own by using 100% ethanol (200 proof alcohol). Housekeepers, custodians and lab technicians dilute 100% alcohol down to 70% to use for cleaning up contaminants, sanitizing bathrooms, killing microbes in schools and sterilizing laboratory cleanrooms.

A 70% alcohol solution is actually better for disinfecting than higher concentrations such as 200 proof (100%) or 190 proof (95%). 70% ethanol is bactericidal. 70% ethanol solutions are used in laboratories, research settings, healthcare facilities, industrial applications and production processes as a reagent and cleaner. In microscopic anatomy settings, a 70% ethanol solution is used for histology tissue preparation. This solution is used in microbiology labs to cold wash pellets during RNA and DNA extraction, analysis and precipitation. High-quality DNA and RNA forms the basis of genomic and genetic investigations. 70% Ethanol is commonly used as an antiseptic in laboratory environments. It has the highest effective concentration at 70% compared to 95% or 100%. This solution is ideal for sterilizing laboratory workbenches and electronics lab benches. It is perfectly suited for formulating alcohol-based hand sanitizers.

Making A 70% Ethanol Solution For Cleaning And Disinfecting

100% ethanol (ethyl alcohol) should be diluted to 70% before it can be used for cleaning. 70% alcohol solutions are frequently used to make disinfectant sprays. 70% ethanol and 70% isopropyl alcohol solutions are commonly used for cleaning and disinfecting public spaces, workplaces, businesses, schools and homes.

Ethyl alcohol is also a great option for cleaning electronics in laboratories and for formulating DIY hand sanitizers. The CDC provides guidance to Americans that want to ensure the cleanliness and safety of their environment.

Making A 70% Ethanol Solution For Cleaning And Disinfecting

70% non-denatured ethanol (food grade) is also used as a solvent by herbal tincture makers. An herbal tincture is a concentrated herbal extract in liquid form. In herbal medicine, alcoholic tinctures are made with different concentrations of ethanol. You can buy ethanol for tinctures and herbal extracts online, here. Herbal tinctures are made by soaking plant materials such as buds, bark, seeds, berries, leaves, stems or roots in ethanol.

Pure 70% ethanol is used to extract resins and other botanical compounds from plants to make liquid botanical concentrates and medicinal oils. You can buy safe ethanol to make botanical extracts, herbal tinctures, perfumes, concentrates and medicinal oils, here. Find out how to make herbal tinctures and extracts with food grade ethanol, here. Learn how to use 190 proof food grade ethanol to make perfume, here.

Use Pure Ethanol To Make 70% Ethanol Solutions

Ethanol is a primary alcohol and known as Ethyl Alcohol, Pure 200 Proof Non-Denatured Food Grade Ethanol, Pure Alcohol, Absolute Alcohol, or Pure Grain Alcohol.

200 Proof Non-Denatured Ethyl Alcohol contains ≥ 99% contents of pure ethanol. It is highly volatile and appears as a colorless liquid with a pungent taste at room temperature. Non-denatured ethanol is deemed safe for human consumption since there are no added toxic chemicals. This makes it the best choice when choosing the right ethanol for disinfectant purposes that will be in contact with food surfaces and highly trafficked areas.

Why 100% Ethanol Is Used For Dilution?

When diluting ethanol at home for use as a disinfectant, the final concentration should be known. If 95% Ethanol were to be used for dilution, it would be possible, however, the final concentration would be less accurate. Therefore, it is imperative that the utmost precision is taken when creating an alcohol solution that is effective at killing germs and viruses that can cause illness.

Why Is 70% The Desired Concentration?

70% ethanol kills organisms such as viruses and bacteria by denaturing their proteins and dissolving the lipids. As a disinfectant, higher concentrations of alcohol become less effective at killing pathogens. In a study conducted by the CDC, they found that the use of 99% alcohol results in “immediate coagulation of surface proteins and prevent passage of the alcohol into the cell.” This means that when the outer cell wall becomes coagulated, it protects the virus or bacteria by preventing ethanol from moving into the cell and destroying it. Additionally, 99% ethanol evaporates rapidly which does not allow time for it to penetrate the cell wall, thus rendering it ineffective against pathogens. Use of 70% alcohol as a disinfectant is advantageous since coagulation of the cell wall proteins proceed at a slower rate, allowing the alcohol to enter the cell. The dilution with DI water is essential to denaturing proteins, and due to the concentration difference between the outer and inner cell wall, 70% ethanol can enter the cell wall and destroy both enzymatic and structural proteins. Thus, this increases the potency of the antibacterial properties.