Isopropyl alcohol (IPA), also known as isopropanol, is a common chemical compound valued as a solvent and disinfectant. Many consumers specifically seek the higher 90% concentration for specialized applications. This guide details why 90% IPA is preferred for certain tasks and where it can be purchased in local stores and online.
Understanding the Need for 90% Concentration
Choosing 90% IPA over the common 70% concentration relates primarily to water content and evaporation rate. A 90% solution contains only about 10% water, a significant reduction compared to the 30% water in a 70% solution. This minimal water content makes the higher concentration a far more effective solvent for non-polar compounds like oils, greases, and certain adhesives.
The reduced water allows the alcohol to evaporate much faster and cleaner, leaving virtually no residue. This rapid evaporation makes 90% or higher IPA necessary for cleaning sensitive electronics, such as circuit boards, CPU components, and optical lenses. The goal is to remove contaminants without introducing moisture that could cause corrosion or damage delicate circuitry.
While 70% concentration is generally more effective for disinfection because the water helps the alcohol penetrate microbial cell walls, the 90% solution is preferred for technical applications. Uses include dissolving flux residue after soldering, removing thermal paste from a computer processor, or cleaning 3D printer beds. For these tasks, the solvent power and quick-drying nature of the 90% concentration are key.
Finding 90% IPA in Local Brick-and-Mortar Stores
Locating the 90% concentration often requires knowing where to look, as it is typically shelved separately from the standard 70% rubbing alcohol. Major pharmacy chains commonly stock 90% or 91% IPA, usually in the first aid aisle alongside bandages and antiseptic wipes. These stores are the most reliable source for smaller bottles of high-concentration alcohol for immediate needs.
Large grocery stores and big-box retailers also frequently carry the 90% concentration. Consumers should check both the first aid and cleaning supplies sections. The packaging may be labeled specifically as an “antiseptic” or “solvent” solution, differing from the traditional rubbing alcohol bottle. If you cannot find it, ask a store associate, as inventory levels for this concentration can fluctuate.
For consumers seeking larger quantities, hardware and home improvement stores often sell IPA in the paint or solvent section. High-concentration alcohol is used in various industrial and cleaning applications, such such as a thinner or degreaser. These locations may carry sizes up to a quart or a gallon, sometimes labeled as a solvent or cleaner rather than a medicinal product.
Sourcing High-Volume or Specialized Online Purchases
For users requiring large volumes, such as gallons, or those needing purity levels above 91%, online purchasing is the most practical option. Major e-commerce platforms offer a wide array of 90% and 99% isopropyl alcohol, providing convenience and competitive pricing. These platforms are ideal for consumers who use high-concentration IPA regularly for electronics repair, laboratory work, or large-scale cleaning projects.
Specialized chemical and industrial supply websites cater to bulk purchasers and laboratories, often selling IPA in five-gallon jugs or 55-gallon drums. These suppliers offer various purity grades, including ACS (American Chemical Society) or USP (United States Pharmacopeia) grades, necessary for specific technical or regulatory requirements. When ordering high-concentration solvents online, be aware of shipping logistics.
Isopropyl alcohol is classified as a hazardous material (HazMat) due to its flammability, which can affect shipping methods and costs. Online vendors must comply with Department of Transportation (DOT) regulations, meaning you may see higher shipping fees or be unable to expedite the delivery of larger containers. Furthermore, some bulk suppliers may restrict sales of high-purity grades to commercial facilities or require a Declaration of Use form before shipping.