How do you make 70% alcohol for disinfection?

Author: Randall Borer  |  Last update: Friday, October 24, 2025

To obtain 1 litre of 70% v/v ethanol:
  1. take 785 ml of 90% v/v ethanol, or 730 ml of 95% v/v ethanol, or 707 ml of 99% v/v ethanol;
  2. add distilled or filtered water to make up a volume of 1 litre;

How to prepare 70% alcohol for disinfection?

We use 70% EtOH to spray down surfaces for quick disinfection before an experiment. In all the various labs I have been in, we make 70% EtOH by mixing 3 parts water and 7 parts whatever the chemistry store calls ``EtOH.''

How to make 70% alcohol solution?

Prepare the 70% v/v ethanol solution:
  1. Add 70 mL of 200 proof ethanol to a 100 mL volumetric flask.
  2. Add distilled water to bring the total volume to 100 mL. Mix thoroughly.

How to make disinfectant spray with 70% isopropyl alcohol?

Notes To achieve at least a 60% alcohol ratio when using 70% Isopropyl Alcohol use a ratio of 9 parts alcohol to 1 part aloe. For a 2 ounce spray bottle that would be 53 mL alcohol and 6 mL aloe vera.

What is the best homemade disinfectant spray?

Alcohol-Based Recipe

In a spray bottle, combine three-quarters cup of water with a cup and a half of isopropyl alcohol. Essential oils can also be added as desired.

Making a 70% Ethanol solution

Can I disinfect with 70 isopropyl alcohol?

- How to properly dilute and use IPA. Solutions of 70% IPA in water should be left on surfaces for 30 seconds to ensure disinfection. Pure (100%) IPA evaporates too quickly for such use and is less effective. - To clean surfaces with soap and water before cleaning with IPA.

What is the ratio of rubbing alcohol to water for disinfecting?

Isopropyl alcohol, particularly in solutions between 60% and 90% alcohol with 10 – 40% purified water, is rapidly antimicrobial against bacteria, fungi, and viruses.

What is the difference between rubbing alcohol and 70% isopropyl alcohol?

Rubbing alcohol is a diluted form of isopropyl alcohol. Sometimes, it also contains other ingredients, such as wintergreen essential oil. While the concentration of isopropyl alcohol is 100%, the concentration of many brands of rubbing alcohol is 70%.

Can you dilute 70% isopropyl alcohol with water?

After filling the bottle with 28.57% distilled water fill the rest of the bottle with a 70/30 isopropyl alcohol. You now have a bottle of 50/50 isopropyl alcohol mix to help remove old protection and ensure you have a clean surface!

How to mix alcohol with water for disinfecting?

It Disinfects (Most) Things

You can mix a 50/50 solution of water and rubbing alcohol to disinfect your hard-surface countertops, like granite and quartz. Hospitals also sometimes use alcohol towelettes to get rid of germs on small surfaces like stethoscopes, scissors, and thermometers.

What proof does alcohol need to be to disinfect?

Alcohol is highly effective at 70% (140 proof) as an excellent disinfectant.

How do you make hand sanitizer with 70 alcohol?

DIY Hand Sanitizer:

2/3 cup rubbing alcohol of at least 70% alcohol concentration. *When using rubbing alcohol with higher alcohol concentrations, add water to the mix.

What is the minimum alcohol for disinfection?

Ethanol at 80% was highly effective against all 21 tested, enveloped viruses within 30 s. Murine norovirus and adenovirus type 5 are usually inactivated by ethanol between 70% and 90% in 30 s whereas poliovirus type 1 was often found to be too resistant except for ethanol at 95% (all test viruses of EN 14476).

How much water to dilute alcohol?

How do you calculate alcohol dilution? To calculate how much of a weaker spirit or water you need to add to dilute your alcohol: Multiply the concentration of the weaker spirit in % (0% for water) by the volume of the stronger spirit. Divide the result by the concentration of the stronger spirit (also in %).

What type of alcohol is best for cleaning?

Generally, isopropyl alcohol is considered safer and better for cleaning and disinfecting your home as it has no toxic additives and kills germs effectively.

How to make disinfectant spray with isopropyl alcohol 70?

Here's how to do it: Combine 1 1/2 cups rubbing alcohol with 3/4 cups water and 15 drops each of lavender and lemon essential oil in a metal or glass spray bottle. You can use this spray to disinfect everything you would typically use Lysol for, including toilets, laptops, bathrooms surfaces, door handles, and more.

Is hydrogen peroxide stronger than alcohol?

Rubbing alcohol kills germs faster but may damage certain surfaces. Hydrogen peroxide is more effective against certain bacteria. Why use hydrogen peroxide instead of rubbing alcohol? You can use it on some surfaces, such as wood or granite, that alcohol might damage.

What disinfects better bleach or rubbing alcohol?

While the relative effectiveness of alcohol and bleach on bacteria and viruses does not vary greatly, it is important not to mix the two agents during cleaning.

What should you not clean with isopropyl alcohol?

11 Things You Should Never Clean with Rubbing Alcohol
  • Clear Acrylic Containers. Clear organizing containers are more popular than ever, especially in spaces like pantries and refrigerators. ...
  • Granite and Marble. ...
  • Wood Pieces or Furniture. ...
  • Painted Surfaces. ...
  • Flammable Surfaces. ...
  • Rubber. ...
  • Leather. ...
  • Delicate Fabrics.

What disinfectant do hospitals use?

Hydrogen Peroxide & Peracetic Acid

Several combination hydrogen peroxide/peracetic acid products are cleared by the FDA as disinfectants in health care settings. Combining peracetic acid with hydrogen peroxide increases its effectiveness, especially against glutaraldehyde-resistant mycobacteria.

Why is 100% alcohol not effective as a disinfectant?

The 100% isopropyl alcohol coagulates the proteins instantly by creating a protein layer that protects the other proteins from further coagulation. Due to this microbes are not killed but remains in dormant stage.

What kills C diff besides bleach?

“Though bleach can be highly corrosive to surfaces, it is effective against C. diff and our goal is to help save people's lives.” As an alternative to bleach, some facilities are experiencing success in the fight against C. diff by using accelerated hydrogen peroxide (AHP) products.

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