What is use of 70% alcohol vs 91% rubbing alcohol?

Isopropyl Rubbing Alcohol (IPA) comes in a variety of strength. Most common are 70%, 91% and 99%. There are a variety of strengths because isopropyl alcohol is used for so many things.

The lower the alcohol concentration, the weaker the solution and the slower it evaporates. Conversely, the higher the concentration, the stronger the solution and the faster it evaporates. These qualities are why different concentrations are used for different purposes.

One use of 70% isopropyl rubbing alcohol is a post-work-out rubdown to soothe exerted muscles. This concentration is used because at 70% alcohol and 30% water, it won’t evaporate before being effective but won’t be strong enough to irritate skin or create uncomfortably strong fumes.

91% and 99% IPA are used for cleaning things that shouldn’t be wet, like computer parts and other electronics. At 99% concentration, IPA will evaporate almost immediately. 70% wouldn’t work in such an application since, with 30% water, the solution will take much longer to evaporate.

IPA is also used for getting ink out of clothing. Sometimes 70% IPA will get the job done. If not, increasing to 91% or 99% may work where the weaker solution was unable.

In situations where the solution strength isn’t important, 70% IPA is the most popular since, containing more water and less alcohol, it is cheaper.

Ever wonder how you can use rubbing alcohol around the house? Here are some must-try household uses for rubbing alcohol shared by Reader's Digest.

1. Use rubbing alcohol to clean bathroom fixtures

Just reach into the medicine cabinet the next time you need to clean chrome bathroom fixtures. Pour some rubbing alcohol straight from the bottle onto a soft, absorbent cloth and the fixtures. No need to rinse – the alcohol just evaporates. It does a great job of making chrome sparkle, plus it will kill any germs in its path.

2. Use rubbing alcohol to remove hairspray from mirrors

When you are spritzing your head with hairspray, some of it inevitably winds up on the mirror. A quick wipe with rubbing alcohol will whisk away that sticky residue and leave your mirror sparkling clean.

3. Use rubbing alcohol to clean venetian blinds

Rubbing alcohol does a terrific job of cleaning the slates of venetian blinds. To make quick work of the job, wrap a flat tool – a spatula or maybe a 6-inch drywall knife – in cloth and secure with a rubber band. Dip in alcohol and go to work.

4. Use rubbing alcohol to keep windows sparkling and frost-free

Do your windows frost up in the wintertime? Wash them with a solution of 1/2 cup rubbing alcohol to 1 quart (1 litre) water to prevent the frost. Polish the windows with newspaper after you wash them to make them shine.

5. Use rubbing alcohol to dissolve windshield frost

Wouldn’t you rather be inside savouring your morning coffee a little longer instead of scraping frost off your car windows? Fill a spray bottle with rubbing alcohol and spritz the car glass. You’ll be able to wipe the frost right off. Ah, good to the last drop!

6. Use rubbing alcohol to clean your phone

Is your phone getting a bit grubby? Wipe it down with rubbing alcohol. It’ll remove the grime and disinfect the phone at the same time.

7. Use rubbing alcohol to remove ink stains

Did you get ink on your favourite shirt or dress? Try soaking the spot in rubbing alcohol for a few minutes before putting the garment in the wash.

8. Use rubbing alcohol to erase permanent markers

Did Junior decide to decorate your countertop with a permanent marker? Don’t worry, most countertops are made of a non-permeable material such as plastic laminate or marble. Rubbing alcohol will dissolve the marker back to a liquid state so you can wipe it right off.

9. Use rubbing alcohol to get rid of fruit flies

The next time you see fruit flies hovering in the kitchen, get out a fine-misting spray bottle and fill it with rubbing alcohol. Spraying the little flies knocks them out and makes them fall to the floor, where you can sweep them up. The alcohol is less effective than insecticide, but it’s a lot safer than spraying poison around your kitchen.

10. Use rubbing alcohol to make a shapeable ice pack

The problem with ice packs is they won’t conform to the shape of the injured body part. Make a slushy, comfortable pack by mixing 1 part rubbing alcohol with 3 parts water in a self-closing plastic bag. The next time that sore knee acts up, wrap the bag of slush in a cloth and apply it to the area.