91% isopropyl alcohol is used for heavy-duty cleaning, disinfecting hard-to-wet surfaces, removing thermal paste from electronics, cleaning circuit boards, and as a general household cleaner for things like mirrors, removing adhesives, and stripping paint in crafts, offering strong solvent action with less water than 70%. While effective for disinfecting viruses and bacteria, 70% alcohol is often preferred for skin antiseptic as it evaporates slower, allowing more contact time, and 91% is better for electronics and industrial cleaning where water isn't ideal.
Multipurpose Isopropyl Alcohol – Often used in medical facilities, hospitals, and pharmaceutics this 91 percent isopropyl alcohol helps effectively clean minor wounds on skin or dirty surfaces as an antiseptic and disinfectant.
You should not use isopropyl alcohol (rubbing alcohol) on wood, painted surfaces, natural stone (marble, granite, quartz), leather, delicate fabrics (silk, wool, rayon, acetate), acrylic, or electronic screens, as it can strip finishes, cause discoloration, damage coatings, or dry out materials. Always test in an inconspicuous spot first and avoid using near open flames due to flammability.
With 91% IPA, the evaporation is instant and protein coagulates, rendering the effect of the IPA greatly reduced. This means that 91% IPA takes a greater time to act and doesn't kill as much bacteria as 70% IPA. The latter is also cheaper.
Skin Contact
Isopropyl alcohol can irritate and damage the skin: Skin Irritation: Prolonged contact can cause redness, dryness, and irritation. In some cases, chemical burns can occur, especially if high concentrations are used.
Do not use rubbing alcohol or hydrogen peroxide. These can further irritate the wound and delay the healing process. Instead, use a washcloth, mild soap and warm water to clean around the wound. Then, irrigate the wound by gently rinsing it in clear, warm running water.
Using isopropyl alcohol and white vinegar together makes a quickly evaporating spray glass and mirror cleaner that competes with national brands. This can also be used to give a nice shine to hard tiles, chrome, and other surfaces.
Isopropyl alcohol, particularly in solutions between 60% and 90% alcohol with 10 – 40% purified water, is rapidly antimicrobial against bacteria, fungi, and viruses. Once alcohol concentrations drop below 50%, usefulness for disinfection drops sharply.
RUBBING ALCOHOL
This substance is generally considered stronger than hydrogen peroxide as it contains a higher percentage of active ingredients usually at 70% compared to the latter at 3%. This solution is commonly used for killing germs and viruses in surgical settings.
91% is fine for surface cleaning where it won't get under components, if you're just wiping things down or cleaning thermal paste off the CPU or such, but I'd stick to 99% for "washing" the board, so to speak.
The general guideline is that about 5% or less IPA can be poured down the sink, so pour a small volume of IPA followed by a lot of water (and repeat until its gone) and it'll be fine. Rinse out the bottle a few times afterwards if you're still worried about peroxide formation.
There are some bacteria that are highly resistant to being killed by alcohol. These include the genera mycobacterium and clostridium. In the hospital setting we often encounter Clostridium Difficile (c. diff).
Not only does alcohol make an excellent bedding and mattress disinfectant spray, but spraying alcohol on sheets also helps to eliminate unpleasant odors caused by sweat, spills, and other sources to leave your bed smelling nice and fresh.
What Are the Uses of Isopropyl Alcohol?
Go ahead and use tap water if you want.) The formula is simple: 'Concentration Required' divided by 'Concentration Supplied' multiplied by 'Final quantity Required'. That will give you the amount of 91% isopropyl alcohol you need to measure out, then dilute to the 'Final quantity required' with your tap water.
Isopropyl alcohol removes oils, adhesives, fingerprints, soldering flux and other contaminants, making it ideal for cleaning electronics. However, it is important to note that only alcohol with a grade of 90% or more should be employed on circuit boards and other internal electronics.
Rubbing alcohol has the same germ and fungal killing properties as hydrogen peroxide. As such, regular application can help eliminate surface infections.
Short answer: For disinfection, the closest like-for-like alternative to isopropyl alcohol is ethanol (ethyl alcohol) at 60–95% for hands and small surfaces. For hard, nonporous surfaces, 3% hydrogen peroxide is another strong option.
In essence, while 91% Isopropyl Alcohol is a valuable chemical product, available from suppliers like Alliance Chemical for its solvent and cleaning properties, it should not be the default choice for tasks where thorough disinfection is the primary goal. For that, 70% IPA remains the scientifically preferred option.
You can buy rubbing alcohol with a concentration of 70% or 99% isopropyl alcohol. Even though you may think the higher concentration is more effective, experts say 70% is actually better for disinfecting. It has more water, which helps it to dissolve more slowly, penetrate cells, and kill bacteria.
Hydrogen peroxide's oxidizing properties can cause it to corrode some metals. It can break down the protective coatings and cause rust spots, discoloration, pitting, or tarnishing on metals like copper, brass, iron, aluminum, and stainless steel.
When you blend rubbing alcohol and baking soda, they don't combine well, creating a less effective, undissolved sludge rather than a paste. You certainly don't have to give up on cleaning with baking soda — it can still be safely and effectively used with vinegar, dish soap, or hydrogen peroxide.
The alcohol dries the ear and kills both bacteria and fungi. The boric acid or vinegar acidifies the ear making it a less hospitable place for bacteria and fungi to grow.
Bleach and rubbing alcohol create chloroform. This combination is highly toxic and can cause damage to your eyes, lungs, and liver. Combining these products can create peracetic / peroxyacetic acid, which can be highly corrosive and irritate your eyes, skin, and respiratory tract.