At 70% concentration, isopropyl alcohol denatures proteins and dissolves cell membranes — more effective than 90% or 99% because the water helps it penetrate bacterial cells.
- • Flammable — keep away from open flames, sparks, and heat sources
- • Use in well-ventilated areas — fumes can cause dizziness and headaches
- • Not a food-safe sanitizer — use vinegar or hydrogen peroxide for food contact surfaces
Keep tightly sealed in original container, away from heat sources and direct sunlight
2–3 years unopened, use within 6 months once opened (evaporates and loses concentration)
What It Does
Isopropyl alcohol (also called rubbing alcohol) is a fast-evaporating solvent that disinfects surfaces, cuts through grease, and leaves a streak-free finish. It’s the go-to ingredient when you need something that dries quickly and completely — electronics, glass, mirrors, and sanitizing sprays.
The key insight: 70% isopropyl alcohol is more effective for disinfection than 90% or 99%. The 30% water content helps the alcohol penetrate bacterial cell walls rather than just evaporating on contact. Higher concentrations evaporate too fast to do the job.
How to Use It
You’ll find isopropyl alcohol in recipes across several categories:
- Glass and mirrors — mixed with water and a drop of dish soap for streak-free shine
- Electronics cleaning — used at 90%+ concentration where rapid evaporation is needed (screens, keyboards, phones)
- Surface disinfection — 70% solution applied directly or in spray bottles
- Stain removal — effective on ink, permanent marker, and adhesive residue
- Windshield washer fluid — prevents freezing in cold-weather DIY formulas
Use 70% for most cleaning and disinfecting. Use 90%+ only when you need fast evaporation (electronics, surfaces that can’t get wet).
Buying & Storage
Available at any drugstore or grocery store. Buy the 70% concentration unless specific recipes call for higher. It’s inexpensive — store brands work identically to name brands.
Keep the cap tightly sealed. Isopropyl alcohol evaporates readily, and an open bottle will lose concentration over time. Store away from heat sources — it’s flammable with a low flash point.
Enhance It
- Streak-free glass cleaner: Combine 1 cup water, 1 cup 70% isopropyl alcohol, and 1 tablespoon white vinegar in a spray bottle. Rivals commercial glass cleaners.
- Quick-dry disinfectant spray: Mix equal parts 70% isopropyl alcohol and water, add 10 drops of tea tree or lavender essential oil. Shake before each use.
- Adhesive remover: Apply 90% isopropyl alcohol to a cloth and hold against sticker residue for 30 seconds. The adhesive dissolves cleanly.
