Isopropyl Alcohol 99% vs Isopropyl Alcohol 70%

Isopropyl alcohol (IPA) is a common chemical used in many different industries and applications. It is a colourless, volatile, and flammable liquid that is widely used as a solvent in medical, industrial, and manufacturing applications.¹ However, there are different percentages of isopropyl alcohol available, and it's important to understand the differences between them.

While both IPA 99% and IPA 70% contain isopropyl alcohol, they are typically selected for different purposes. IPA 99% is commonly used when a highly concentrated solvent or cleaning agent is required, while IPA 70% is often preferred for applications where slower evaporation and disinfecting properties are important.

Main Difference Between 99% and 70 % Isopropyl Alcohol

The main difference between isopropyl alcohol 99% and isopropyl alcohol 70% is the concentration of alcohol in the solution. Isopropyl alcohol 99% contains 99% alcohol and 1% water, while isopropyl alcohol 70% contains 70% alcohol and 30% water. Although IPA 99% is more concentrated, the added water content in IPA 70% can improve antimicrobial effectiveness by slowing evaporation and allowing more time for protein denaturation.²

Uses and applications of isopropyl alcohol 99%

Isopropyl alcohol 99% is commonly used in industrial and manufacturing settings where a strong and fast-acting solvent is needed.¹ It is also used in the medical field for cleaning and disinfecting surfaces and equipment. The high concentration of alcohol in isopropyl alcohol 99% makes it an effective solvent for removing contaminants and cleaning surfaces. However, higher alcohol concentrations are not always preferred for disinfection because rapid evaporation can reduce contact time on surfaces.²

Some common uses of isopropyl alcohol 99% include:

• Cleaning and disinfecting electronic components and equipment
• Cleaning 3D Printers
• Removing grease, oil, and other contaminants from metal surfaces
• Sterilizing medical equipment and instruments
• Cleaning and disinfecting laboratory equipment
• Preparing surfaces for painting or adhesive application

Uses and applications of isopropyl alcohol 70%

Isopropyl alcohol 70% is a more diluted solution than isopropyl alcohol 99%. However, the presence of water helps slow evaporation and supports the protein denaturation process responsible for alcohol's antimicrobial activity. According to the CDC Guideline for Disinfection and Sterilization in Healthcare Facilities, alcohol solutions between approximately 60% and 90% demonstrate optimal bactericidal activity, making 70% isopropyl alcohol a commonly used concentration for healthcare disinfection. ²

Some common uses of isopropyl alcohol 70% include:

• Cleaning and disinfecting skin before injections or minor procedures
• Wiping down surfaces in the home or office to kill germs and bacteria
• Cleaning and disinfecting medical equipment that is not heat sensitive
• Cleaning and disinfecting electronic devices like smartphones and computers
• Preparing surfaces for adhesive application or as a solvent in thinners

In summary, isopropyl alcohol 99% and isopropyl alcohol 70% are both useful chemicals for cleaning and disinfecting surfaces. IPA 99% is commonly selected for solvent and industrial cleaning applications, while IPA 70% is widely used for surface disinfection and antiseptic applications where effective antimicrobial activity and sufficient contact time are required. Understanding the differences between these two solutions can help you choose the right product for your needs.

Is Isopropyl Alcohol 99% better than Isopropyl Alcohol 70%?

Whether isopropyl alcohol 99% is better than isopropyl alcohol 70% depends on the specific application and use case. Isopropyl alcohol 99% is a stronger and more concentrated solution, which makes it more effective at killing bacteria, viruses, and other microorganisms as a surface disinfectant. It is commonly used in industrial and medical settings where a strong and fast-acting solvent is needed. However, because of its high concentration, it can evaporate quickly and may not be as effective for certain applications.

On the other hand, isopropyl alcohol 70% is a more diluted solution that may take longer to work but can be effective for household and consumer applications. It is commonly used for cleaning and disinfecting skin before injections or minor procedures, wiping down surfaces in the home or office, and cleaning electronic devices like smartphones and computers.

In summary, whether isopropyl alcohol 99% is better than isopropyl alcohol 70% depends on the specific application and use case. For industrial and medical settings that require a strong and fast-acting solvent, isopropyl alcohol 99% may be more appropriate. For household and consumer applications, isopropyl alcohol 70% may be more suitable.

References

1. Logsdon JE, Loke RA. Isopropyl Alcohol. In: Kirk‐Othmer Encyclopedia of Chemical Technology. Hoboken (NJ): John Wiley & Sons; 2000. doi:10.1002/0471238961.0919151612150719.a01.
2. Centers for Disease Control and Prevention. Chemical disinfectants. Guideline for Disinfection and Sterilization in Healthcare Facilities. 2023 Nov 28. Available from: https://www.cdc.gov/infection-control/hcp/disinfection-sterilization/chemical-disinfectants.html