A Complete Guide to Isopropanol
In this Complete Guide to Isopropanol, we’ll explore what it is, how it’s made, its uses, hazards, and specifications. You’ll also find further information and reading material in the links at the bottom of this page, and of course you can buy isopropanol from ReAgent, one of the UK’s leading isopropanol suppliers.
What Is Isopropanol?
Isopropanol is known by various names: isopropyl alcohol, propan-2-ol, 2-propanol, sec-propyl alcohol, and IPA. To avoid confusion in this article, we will call it isopropanol.
Isopropanol has the chemical formula CH3CHOHCH3 and is a colourless, flammable liquid with a pungent smell similar to rubbing alcohol. Indeed, isopropanol is an alcohol – the simplest example of a secondary alcohol. This means that its carbon atom is attached to two other carbon atoms.
Properties of Isopropanol
Some properties of isopropanol include:
- Isopropanol is miscible in water, ethanol, acetone, ether, benzene, and chloroform…
- …but it isn’t miscible with salt solutions and can be separated from aqueous solutions by adding a salt
- Isopropanol increases in viscosity when cooled, and freezes at −89°C
- It has important solvent properties and can dissolve most oils, gums, alkaloids, and organic resins
- It also has cooling, cleansing, and antiseptic properties
Like most secondary alcohols, isopropanol reacts with active metals to form alkoxides (these alkoxides are also called isopropoxides), and reacts violently with oxidising agents.
When isopropanol is oxidised, for example by using an oxidising agent such as chromic acid, it forms acetone, the corresponding ketone.
How Is Isopropanol Made?
Isopropanol can be made in a few different ways:
Indirect hydration uses refinery-grade propylene (or propene) and sulphuric acid to make isopropanol. The chemical reaction produced by these two substances forms a mixture of sulphate esters which are then hydrolysed by steam to produce isopropanol by distillation.
Research into ways of making isopropanol has led to a more direct process which is less energy intensive, has a higher yield, and is more cost-efficient. In the direct hydration process, a chemical reaction takes place between propene and water at high pressure and with an acidic catalyst. This process requires higher-grade propylene than the indirect hydration method.
This method of making isopropanol, like the indirect method, requires that it is separated from water and other by-products by distillation.
Hydrogenation of Acetone
A third method of making isopropanol is by hydrogenating acetone over nickel or a mixture of copper and chromium oxide. This process is useful when there is excess acetone production and an abundance of the chemical available.
Uses of Isopropanol
Isopropanol is used to manufacture a range of industrial and domestic chemicals, including antiseptic, disinfectant, and detergent.
Isopropanol as a Solvent
Isopropanol is a widely used solvent due to its ability to dissolve non-polar compounds, evaporate quickly, and leave practically no residue. Compared to alternative solvents it also has relatively low toxicity. Along with ethanol, n-butanol, and methanol, isopropanol is an alcohol solvent – we produce about 7 million tonnes of these alcohol solvents globally every year.
Examples of isopropanol’s use as a solvent and cleaning agent are:
- Cleaning electronic devices during manufacture
- As an ingredient in glass cleaners, liquid soap, and aerosols
- Coating and dye solvent in synthetic polymers
- In primers and paints
- Extracting and purifying natural products including vegetable oil, resins, wax, colours, flavourings, and vitamins
- In cosmetics such as nail varnish, deodorant, and shampoo
Isopropanol is used as a chemical intermediate (meaning the substance formed during a chemical reaction before reaching the desired product). In this way, it is used to synthesise:
- Isopropyl acetate
- The herbicide sodium isopropylxanthate
- Titanium isopropoxide, a catalyst
- Aluminium isopropoxide, a chemical reagent
Isopropanol is also used in the production of acetone.
Isopropanol is used extensively in the pharmaceutical and medical industries because of its low toxicity. It is an ingredient in rubbing alcohol, disinfecting pads, hand sanitiser, and as a water-drying aid especially when treating swimmer’s ear.
When sold for consumer use, isopropanol is mixed with water at concentrations of around 70% isopropanol to water or 91% isopropanol to water.
Isopropanol’s Use in the Automotive Industry
For consumer use, isopropanol is used in aerosol form as a vehicle de-icer. If you have a DIY bent, you can also use it as windscreen wiper fluid when mixed with water.
For industrial and commercial use in the automotive industry, isopropanol is an ingredient in fuel additives. It solubilises the water contained in the fuel, preventing it from separating and freezing at low temperatures. Isopropanol is also used to remove brake fluid traces from hydraulic braking systems to prevent contamination of brake pads which can lead to inefficient or damaged braking.
Isopropanol is a relatively low-toxic substitute for formaldehyde and other preservatives and is used in solution form to preserve lab specimens.
It is also used in DNA extraction, as DNA is insoluble in isopropanol.
Other uses of isopropanol are:
- A coolant in making beer
- A dehydrating agent
- A heat-exchange medium
- A flavouring agent tea and beer
A historical use of isopropanol was in animal anaesthesia by inhaling fumes or ingestion, although this use is now prohibited due to its negative effects such as respiratory irritation, internal bleeding, and sight problems.
Can You Drink Isopropanol?
While isopropanol is an alcohol (it is also known as isopropyl alcohol and rubbing alcohol), it is definitely not an alcohol you should drink. Not only would it taste incredibly bitter, but drinking it can have fatal consequences.
While every alcohol can be deadly if you drink enough of it, isopropanol is typically 70-90% pure alcohol. As rubbing alcohol, isopropanol has chemicals added to it (called denaturants) which make it unsafe for human consumption. These chemicals are added exactly in order to discourage recreational consumption of isopropanol. Please don’t drink it.
Hazards Of Isopropanol
You can be exposed to isopropanol through inhalation, absorption through the skin or ingestion. Domestically, this is especially the case when using rubbing alcohol. Symptoms of isopropanol poisoning when inhaled include headaches, skin, eye and respiratory irritations, dizziness, nausea, vomiting, difficulty breathing, coma, and even death. Symptoms occur rapidly.
If you work with isopropanol, you should be especially aware of its flammability. It should be kept away from ignition points, heat, and open flames.
You should handle isopropanol with care, wearing protective clothing and equipment – such as goggles and gloves – and always in a well-ventilated area.
Propan-2-ol / Isopropanol (General Use) Specification
|Maximum Limits of Impurities|
|Acidity (Acetic Acid)||<0.002||%|
|Non Volatile Matter||<1||mg/100ml|
|Weight per ml at 20°C||0.784 – 0.786||g|
Isopropanol Material Safety Data Sheet (MSDS)
You can find the material safety data sheets for various grades and concentrations of isopropanol below. These MSDSs list the potential hazards (including health, fire, reactivity and environmental hazards) of isopropanol and how to use or work with it safely.
- Isopropyl Alcohol (Analytical Use) Material Safety Data Sheet
- Isopropyl Alcohol (General Use) Material Safety Data Sheet
- Isopropyl Alcohol (Laboratory Use) Material Safety Data Sheet
- Propan-2-ol / Isopropanol (Analytical Use)
- Propan-2-ol / Isopropanol (General Use)
- Propan-2-ol / Isopropanol (Laboratory Use)
Where To Buy Isopropanol
Businesses Buying Isopropanol
If you are a business looking for a recognised, reputable chemical company, a chemical supplier (such as ReAgent!) is probably just what you need. A good chemical company will:
- Be reliable
- Have a proven track record
- Be an expert supplying a range of concentrations
- Be able to advise the best chemical for your needs
- Offer free technical support before you buy, plus after-sales support
- Have quality accreditations
- Provide certificates of conformity and analysis if needed
However, many chemical companies don’t supply isopropanol direct to consumers. This is the case at ReAgent, where we only supply chemicals to businesses.
Useful Isopropanol Resources
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