Safety Talks – Isopropyl Alcohol

What is Isopropyl Alcohol?

Isopropyl Alcohol is a common chemical used in a variety of industrial and consumer capacities. Isopropyl Alcohol is colorless, however it does have a strong odor and is a flammable chemical compound. Isopropyl alcohol is also known as 2-propanol, sec-propyl alcohol, IPA, or isopropanol.

70% Isopropyl Alcohol

Isopropyl alcohol is very effective against microbial bacteria, fungi, and viruses in concentrations between 60% and 90%. However, concentrations higher than 90% doesn’t increase effectiveness against bacteria, fungi and viruses. In order for the Isopropyl alcohol to be effective, there must be enough presence of water. This percentage of water needs to be at least more than 10% within the solution. Thus, the mixture of 70% Isopropyl alcohol and 30% water works best.

The water acts as a catalyst and plays a major role in denaturing the proteins of cell membranes of vegetative cells. In addition, the presence of water slows down evaporation and increases the surface contact time with the membrane. With 91% IPA, the evaporation is instant and protein coagulates, rendering the effect of the IPA greatly reduced.

This means that 91% IPA takes longer to act and doesn’t kill as much bacteria as 70% IPA.

99% Isopropyl Alcohol

This mixture of IPA is more commonly used as a solvent or cleaning agent for industries that produce products that are sensitive to water. This type of IPA mixture evaporates rapidly which makes it useful in computers and electronics manufacturing. If a chip or circuit board needs a quick clean up if something is spilled; 99% IPA is the way to go. However, rapid evaporation does have a downside in that the shelf life of this mixture is not as long as other IPA mixtures.

Both the 70% & 99% mixtures are non corrosive to metals and are plastic safe too. They are ozone safe and have a low impact on climate. Both mixtures are flammable, the 99% variant much more so because of its high flash point.

What is Isopropyl Alcohol used for?

In 1920, isopropyl alcohol was first produced by Standard Oil by hydrating propene. At the time, it’s major use was not rubbing alcohol but instead for oxidation to acetone, which was first extensively used in World War 1 for the preparation of cordite.

Today, Isopropyl alcohol is used in the manufacture of a wide variety of industrial and household chemicals and is a common ingredient in chemicals such as antiseptics, disinfectants, and detergents. 

Medical Uses

Isopropyl alcohol has many medical uses including as a water-drying aid for the prevention of otitis externa, better known as swimmer’s ear. It is also used in rubbing alcohol, hand sanitizer, and disinfecting pads typically in a concentration between 60%-70%.

Cleaning Uses

Isopropyl alcohol is commonly used for cleaning eyeglasses, electrical contacts, audio or video tape heads, DVD and other optical disc lenses, and removing thermal paste from heatsinks on CPUs. It is used widely as a solvent and as a cleaning fluid, especially for dissolving oils. 

Automotive Uses

A major ingredient in “gas dryer” fuel additives, isopropyl alcohol solubilizes water in gasoline. Once soluble, water does not pose the same risk as insoluble water, as it no longer accumulates in the supply lines and freezes but instead is consumed with the fuel itself.

In addition to fuel additives, isopropyl alcohol is also used in an aerosol form as a windshield or door lock de-icer. It is also used to remove brake fluid traces from hydraulic braking systems, so as to prevent poor braking conditions created by contaminated brake pads.

Isopropyl Alcohol Safety Considerations

Isopropyl alcohol is highly flammable and can easily ignite. Vapors may form explosive mixtures with air and use of water spray to fight fires may be inefficient. Isopropyl alcohol should be kept away from heat, sparks, flames and other sources of ignition. A flammable safety cabinet is the best storage option.

Isopropyl Alcohol Health Hazards

Isopropyl alcohol is absorbed through the skin and can cause irritation of the skin, in lower exposure, and serious illness if exposed for longer durations or if it is ingested into the body. 

Some common side-effects of Isopropyl alcohol poisoning are:

  • Dizziness
  • Stomach pain
  • Nausea
  • Rapid heart rate
  • Low body temperature
  • Slurred speech
  • Slow breathing
  • Vomiting
  • Unresponsive reflexes
  • Throat pain or burning
  • Seizure
  • Coma

If you experience any of the above symptoms from exposure to IPA, the first step is to get to a place with fresh air and remove yourself from further exposure.

Isopropyl Alcohol First Aid and handling

Ingestion – Individuals who are conscious and not convulsing should drink one or two glasses of water to dilute the chemical. Do not induce vomiting, as the chemical can be aspirated into the lungs causing further damage.

Inhalation – Again, the individual exposed should be moved to an area with fresh air and medical help should be requested. In cases with high-level exposure, medical personnel should also administer oxygen and fluids to provide respiratory support.

Skin Contact – The skin exposed to IPA should be flooded with water and then gently washed with soap and water. If exposed to a larger amount on your skin, wash and monitor for signs of poisoning and seek medical assistance if symptoms occur. 

Eye Contact – Eyes should immediately be flushed with water or normal saline solution for 20 to 30 minutes or longer. When flushing the eyes, lift the upper and lower eyelids occasionally to ensure the eyes are completely flushed of the chemical.

Isopropyl alcohol is readily absorbed through the skin. In the event of a large spill on the skin may cause accidental poisoning. Small amounts of IPA on the skin is generally not dangerous, but repeated exposure to skin can cause drying, cracking, itching, redness and rash. Prolonged skin exposure can cause corrosion of the skin. Always wash thoroughly with soap and water when skin contact occurs.

Always use Isopropyl alcohol in a well ventilated area and use proper safety equipment in the event of a spill. If someone experiences breathing problems, the person should be immediately removed and placed in an area with fresh air. If the person’s breathing is still impeded, call 911 immediately.

Storage and Disposal of Isopropyl Alcohol

As mentioned earlier in this article, the best storage option for Isopropyl alcohol is a flammable safety cabinet. If that is not an option, keep in mind that Isopropyl alcohol should be stored in a tightly closed container in a cool, dry, well-ventilated area. Also, keep it away from ignition sources including sparks, heat, and flame. 

Disposal of Isopropyl alcohol should be done in accordance to your local or state regulations. Most communities will have some sort of hazardous waste recycling for larger amounts of chemicals.   


Isopropyl alcohol is a useful chemical in many applications, both industrial and consumer. However, don’t forget that you need to take steps to keep yourself safe from over-exposure. Things like Personal Protective Equipment to keep IPA from contacting your skin or eyes is a good place to start. Also remember to handle IPA in a well ventilated area to minimize inhalation of IPA fumes; it may be appropriate to also wear a mask to further diminish the exposure. 

Finally, take into consideration the storage conditions of this chemical in order to limit the chance of accidental ignition due to the high flammability of IPA.