Ask iFixit: Everything You Wanted to Know About Isopropyl Alcohol
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Ask iFixit: Everything You Wanted to Know About Isopropyl Alcohol

We’ve talked before about how the pandemic has shown some serious strain on our global supply chains. Once upon a time it came for isopropyl alcohol. While IPA may not be hard to find, or triple the usual cost, we’ve still got the details, and alternatives, right here for you.

We know, rely on, and recommend isopropyl alcohol (a.k.a. isopropanol, or IPA) for many of our techniques and guides. It’s pretty simple stuff, but it is sold in different ways, and recommended for a myriad of uses.

Understandably, people have questions. Is “rubbing alcohol” or “surgical spirit” the same thing? What percentage of isopropyl do I need for electronics work or disinfecting? Can I use anything else on my electronics? And, hey, is this stuff going to catch on fire if I cause a spark?

Let’s clean up these questions.

What Is Isopropyl Alcohol? How Is It Made?

Isopropyl alcohol is a clear chemical that is flammable. It smells a bit like vodka or other spirits, just without any kind of scent other than alcohol. Manufacturers make it by adding water to propene (itself steamed and heated out of propane and other hydrocarbons), then distilling the mixture to a desired strength, similar to how liquor is made.

It’s usually sold in a few set percentages of alcohol-to-water: 70% and 90/91% are most common, but you’ll sometimes see 60% or, at hardware and specialty supply stores, 95-99%.

Why Do You Recommend Isopropyl Alcohol for Cleaning Electronics and Removing Adhesive?

It’s widely available (at least in non-crisis times), it’s relatively inexpensive, and it does a few important jobs at once. Isopropyl:

  • Dissolves oils, adhesives, soldering flux, residues, fingerprints, and other contaminants
  • Leaves no oils or traces, unlike many ethanol compounds
  • Evaporates quickly (at least in spaces above 60 degrees Fahrenheit)
  • Is relatively non-toxic, assuming you’re working in a decently ventilated area
  • Disinfects viruses and bacteria (at concentrations of 60/70 percent)
  • Mixes with water fully and then evaporates with it, making it the best way to remove and prevent corrosion damage from liquid spills on electronics.

I Can Only Find 70% Isopropyl Alcohol. Can I Use It to Clean My Devices?

It’s best to avoid using any isopropyl mixture below 90% on circuit boards and other electrical bits. If you’re simply cleaning the adhesive off something metal or plastic, 70% might do in a pinch, but you’ll want to be sure not to spill it onto circuits or wires. There’s enough water in that lower-grade stuff that it will take longer to evaporate, and may leave behind trace impurities from the water when you’re finished.

90% works fine for most purposes. 99% might be technically optimal, but it’s trickier to find in some places. Grab a bottle when you can find it, but don’t worry too much about the last 10%. 

What About Other Compounds that Have High Alcohol Percentages? Nail Polish Remover? 

We suggest you stick to something you know and has known ingredients: isopropyl alcohol and water. Rubbing alcohol, denatured alcohol, surgical spirits, and other high-alcohol solutions often contain other chemicals, scents, or other substances that have different properties than IPA, or are a bad idea around boards and wires. If the package doesn’t have isopropyl alcohol as the only active ingredient, and water as the only inactive, it might be best to hold out.

This is especially true for nail polish remover, or acetone. Acetone is a stronger adhesive remover than isopropyl alcohol, at least for the kinds of adhesives often used in electronics. But acetone also damages ABS plastics, the most common in electronics. That’s why we include just a little acetone in our adhesive remover, to make it even more effective, but not so much that it will melt plastics, presuming you wipe it up fairly quickly.

What About Vodka?

Most vodka, and most liquor generally, is around 40% alcohol by volume, so no, it’s a bad idea for electronics repairs.

But I’ve Got This Booze That’s Really High-Proof.

You’re better off saving that for large batches of party punch, given the cost. Ethanol/ethyl alcohol is not the same thing as isopropyl alcohol, either.

Will Isopropyl Damage My Screen? My Laptop Keys? Other Things Inside My Device?

We’ll only tell you to use isopropyl alcohol on surfaces where it’s safe to do so in our guides. And we try to warn you when spills or an abundance of liquid can cause damage. In our guide to replacing the battery in a 2013 15-inch MacBook Pro, we note that our own adhesive remover (the majority of which is isopropanol, but also a small amount of acetone) can damage the anti-glare coating on your display, and the plastic on the embedded speakers.

Generally, metal and circuit boards don’t have a problem with adhesive remover, but you should be cautious around display components (especially the LCD or OLED backing behind a screen), plastics, and, obviously, anything that is glued together that you want to stay glued together. Generally, a cautious approach is best; even better is a little pre-fix research. Electronics cleaning vendor Techspray has a material-by-material list of what reacts to isopropyl alcohol. If you’re not sure, don’t put a bunch of alcohol on it (a good general rule for life, you might find).

We recommend isopropyl alcohol as one of the steps to cleaning out your keyboard. But note that we recommend a damp towel, not pouring the stuff straight on.

Many device makers are clarifying what is safe to wipe with sanitizing solutions. Microsoft says you can clean the felt-like Alcantara cloth on its Surface products with a 70% alcohol solution. Apple used to suggest that you had to be really careful around its screens to avoid removing the oleophobic coating, but now using a 70% solution is at the top of the official “Cleaning your iPhone” page. Searching for cleaning or maintenance instructions for your device is a good place to start.

It’s Flammable Stuff, with a Poison Warning Label On It. How Concerned Should I Be?

Nearly every iFixit guide is built around getting to the battery and disconnecting it before you do any work that would put you in contact with electrical circuits. Once the battery is disconnected (or you’ve unplugged the device, if it lacks a battery), your chance of accidentally creating a spark, or exposing isopropyl to heat, is much reduced. Electrostatic discharge from your clothing or rugs is quite unlikely to cause a fire, but it’s always a good idea to avoid it. The main thing you want to look for, then, is larger capacitors in bigger devices, which can store a charge even after disconnection from power. For most repairs, this isn’t an issue.

Regardless of the use, you should treat isopropyl alcohol like any other flammable substance with strong vapors in your house. Don’t expose it to flame or high heat or sparks. Keep it tightly closed when not in use (this also prevents wasteful evaporation). And don’t use it in enclosed spaces with poor ventilation.

A big thanks to Old Turkey, Mayer, and other iFixit Answers VIPs who laid out a lot of this knowledge. Got any more questions about isopropyl alcohol, or anything else repair-related? You can help us decide what to tackle next. Ask us in the comments, or tag us on social media with #AskiFixit.