A Complete Guide to Isopropyl Alcohol

Isopropyl alcohol, IPA or rubbing alcohol, is probably the solvent most people already have in the house, and it occupies almost the opposite corner from an aromatic like xylol (xylene). It is water-friendly, relatively low in toxicity, and gentle enough for skin and electronics, which is exactly why it turns up everywhere from the medicine cabinet to the repair bench.

The essentials:

• What it is: an alcohol, isopropanol (C3H8O), a clear liquid, usually sold diluted with water.
• Common strengths: from about 70 percent (household rubbing alcohol) up to 99 percent for technical use.
• Mixing: mixes freely with water, unlike xylene.
• Evaporation: fast and clean, leaving little or no residue.
• Flash point: around 12 °C, so it is flammable despite its mild reputation.

Its strengths are cleanliness and safety rather than raw power. IPA is a go-to for cleaning electronics and circuit boards because high-purity grades flash off without residue, a disinfectant and antiseptic in the higher concentrations, a glass and surface cleaner, and a handy remover for light adhesive residue and flux. What it is not is a strong solvent for oil-based paints, cured coatings, or heavy resins, the jobs where xylene’s aromatic strength is needed. It dissolves polar and lighter materials well and leaves the tough nonpolar ones to stronger solvents.

On safety it is the gentler option but not a harmless one: it is flammable, its vapor can cause dizziness in a closed space, and it is toxic if swallowed in quantity. Used with reasonable ventilation and kept from flame, it is about as user-friendly as solvents get. The clean split with xylol is easy to remember: reach for isopropyl alcohol for electronics, disinfecting, and clean, water-compatible cleanup, and for xylene when the job needs a strong, oil-dissolving aromatic that IPA cannot handle.