Isopropyl Alcohol 99% Versus Isopropanol 70% for Cleaning Medical Device Parts in Your Lab

There has been a long standing debate between cleaning chemicals Isopropyl Alcohol 99% (IPA 99) and Isopropyl Alcohol 70% (IPA 70). These two chemicals are both used as disinfectants by different pharmaceutical companies to purify laboratories and medical equipment. They are even used to clean different electronic parts for medical equipment manufacture.

The chemicals are completely identical in terms of molecular structure, but they have different purity grades. They are also suitable for the clean up of different chemical spills.

It depends on how concentrated the spill is, but it’s usually cleaned up by both 70% and 99% isopropyl alcohol. Knowing the difference between the two is also part of lab safety with chemicals.

Isopropyl Alcohol 70%

Between the concentrations of 60% and 90%, isopropyl alcohol is very effective against micro contaminants. These include microbial bacteria, fungi, and viruses. These need to be cleaned up in a lab for purity’s sake as well as the sake of stopping disease and infection. If bacteria, fungi, or viruses are left to grow within a laboratory, they may react with other chemicals, compromising experiments. There is also a risk that they may cause explosive reactions or allergic reactions that can harm lab researchers.

The reason for such a large amount of water needed to dilute the alcohol is simple. It needs water to be reactive. Water has to be greater than 10% in concentration to work best. It acts as a catalyst and has a large role in denaturing proteins. This means it can rupture or otherwise damage the cell walls or membranes of cells; hence, its effectiveness against bacteria and viruses. 

IPA 70% solutions are great at breaching the cell walls of plant cells. These are much thicker than the cell membranes, which protect bacteria or animal cells. The presence of water also slows down the evaporation of IPA. Since it’s an alcohol, it is volatile in its pure form so it can vaporize very quickly. Water also allows the contact time and area of the IPA to be increased. This amplifies the effect of IPA on any surface or any substance.

With other 90% of IPA, the solution would have minimal effect on proteins and bacteria. The evaporation would be extremely quick and almost instant. This would mean that both the time and effective contact with the substance and area would be reduced.

Thus, 70% IPA is much more economical than 90% IPA and doesn’t kill as much bacteria. Hence, it’s perfect for cleaning labs. 

Isopropanol 99%

Since 99% IPA doesn’t have nearly any water content at all, it’s great for cleaning industrial equipment. This equipment is extremely hydrophobic and thus requires solvents that evaporate or vaporize very quickly. It can be used as a solvent for industries that also produce substances that are hydrophobic. If those substances are sensitive to water, there is a case to be made for 99% IPA. Otherwise, labs and medical equipment should be cleaned with 70% IPA.

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Other places where 99% IPA is effective is in computer or electronics labs. These labs prefer to have solvents that can vaporize quickly. That way, they can’t damage any components of the machines or the products. During the design of chips and circuit boards, this is very useful. Integrated circuits need cleaning to stay optimal as contaminants can significantly reduce their efficiency.

Also, work area spills are quite common in electronics and medical labs. Hence, if there is any hydrophobic equipment that needs to be cleaned, 99% IPA is the best option.

The downside of this is that 99% IPA has a short shelf life. Since its flash point is so low, it will definitely evaporate while it’s sitting on the shelf. However, due to that rapid evaporation, there is very little chance of dilution of alcohol. During its entire shelf life, it will remain more or less, 99% IPA. Hence, its alcohol content will be preferred for greater consistency.

The best part about 99% IPA for industrial equipment though, is that it’s non-corrosive. Hence, metals, plastic, etc., are both safe. So any manufacturing equipment and any products are both safe from any corrosion. 99% IPA also is ozone-safe and has a low impact on the climate. However, due to its high alcohol content, it is much more sensitive to fire. Its high flash point deems that it should be separate from any heat at all times.

In conclusion, if you want to clean your lab for spills and general contaminants, 70% IPA is the answer. However, know that 99% IPA is great for industrial equipment since it evaporates quickly. Both are great chemicals for cleaning; the applications just need to be chosen a little differently.

For over 40 years, Lab Pro has been committed to providing medical device cleaning alcohol, in California. Come visit the biggest Lab Supply showroom in California, or contact us online or at 888-452-2776.