Isopropyl alcohol (IPA) is a colorless, volatile, and flammable liquid. It is a widely used chemical compound recognized for its properties as both a solvent and a disinfectant. This substance finds applications in domestic, industrial, and medical settings, ranging from general surface cleaning to specialized manufacturing processes. IPA is commercially available in various concentrations, with the most common being 70% and the highly pure 99% solution.
Why 99% Concentration Is Important
The choice of isopropyl alcohol concentration depends entirely on its intended application, and the 99% concentration serves a unique technical purpose. The primary difference between the common 70% solution and the 99% concentration lies in the amount of water present. The 99% solution is nearly anhydrous, containing less than one percent water, which dictates its utility in water-sensitive environments.
This minimal water content is preferred in applications requiring fast evaporation to prevent liquid damage. When cleaning delicate electronics, such as circuit boards or optical lenses, the rapid evaporation of 99% IPA helps avoid moisture-related corrosion or short-circuiting. The high purity also makes it a more effective solvent for dissolving non-polar contaminants like oils, greases, and flux residue. It leaves virtually no trace film or residue behind, which is important for precision cleaning.
Conversely, the 70% concentration is generally more effective as an antiseptic or disinfectant because water is beneficial for microbial destruction. The water acts as a catalyst, slowing the evaporation rate and allowing the alcohol to better penetrate the cell walls of microorganisms. When a 99% solution is used for disinfection, it can instantly coagulate the proteins on the outside of the cell wall, shielding the interior and allowing the microbe to remain dormant. Therefore, 99% concentration is superior for cleaning electronics, while the 70% solution is the standard for general disinfection.
Retail Locations and Sourcing Options
Locating 99% isopropyl alcohol can be more challenging than finding the widely stocked 70% solution, as it is considered a specialized industrial-grade cleaner. Consumers have several reliable channels for purchasing this higher concentration.
Physical Retail Options
Large home improvement or hardware store chains often stock 99% IPA in their chemical or paint thinner sections, sometimes in larger volume containers like gallons. Certain large supercenters and pharmacies may also carry the 99% solution, though it is often stored behind the counter rather than on the main shelves with the common rubbing alcohol. It is beneficial to check with pharmacy staff, as they may store higher-concentration alcohol for specific medical or compounding purposes.
Specialized electronics stores that cater to hobbyists, repair technicians, or computer builders are reliable sources for smaller bottles of 99% IPA, often marketed specifically as an electronics cleaner. Industrial chemical suppliers, which serve businesses, also offer the product in bulk quantities, although they may require a commercial account or specific minimum order sizes.
Online Marketplaces
Online marketplaces and e-commerce platforms offer the widest selection of volumes and purity grades, including the 99% concentration. Buying online provides access to brands specializing in laboratory or technical chemicals, which may offer purity certification like ACS grade. When ordering online, be aware of shipping restrictions, as IPA is classified as a flammable liquid subject to specific transport regulations.
Purchasing Considerations and Safe Handling
Volume and Purity
The product is typically sold in volumes ranging from small pints to full gallons, and purchasing in larger volumes usually results in a lower cost per ounce. Price fluctuates based on the purity rating and whether the product is marketed for general cleaning or specialized technical use. If buying for applications requiring the highest purity, such as laboratory work, look for a product that specifies a grade like “ACS Grade.” For most general cleaning of electronics, standard 99% purity is sufficient.
Safety and Handling
The high concentration of 99% IPA makes safety precautions particularly important due to its enhanced flammability and rapid vaporization. IPA vapor is heavier than air and can travel a considerable distance to an ignition source. Therefore, it must be used only in a well-ventilated area to prevent a dangerous buildup of flammable vapors.
Proper storage is necessary to maintain safety and product integrity. IPA is highly flammable and should be kept away from all heat sources, sparks, and open flames. Containers must be kept tightly closed in a cool, dry area. The substance is hygroscopic, meaning it readily absorbs moisture from the air, which can lower its concentration and effectiveness over time. Furthermore, eye protection and chemical-resistant gloves should be worn to prevent direct skin or eye contact, and the product must be stored securely out of the reach of children and pets.