What Is Isobutanol?
Isobutanol, also called isobutyl alcohol, 2-methyl-1-propanol, or IBA, is a branched-chain primary alcohol with the molecular formula C4H10O and CAS number 78-83-1. It is a colorless, flammable liquid with a characteristic, slightly sweet alcohol odor and moderate water solubility. Isobutanol is produced industrially by the oxo process from propylene or by fermentation routes, and it is widely used as a solvent and chemical intermediate.
Is Isobutanol Toxic?
Among the four butanol isomers, isobutanol is generally considered one of the least toxic. However, it is still classified as harmful if swallowed, and it can cause irritation to the eyes, skin, and respiratory tract. The key risk is not acute poisoning from brief contact but repeated or high-concentration exposure, which can irritate mucous membranes and, in severe cases, depress the central nervous system. It must be handled with normal industrial hygiene controls.
How Isobutanol Enters the Body
Isobutanol can be absorbed through three routes. Inhalation of vapors is the most common occupational route, especially in warm, poorly ventilated areas. Skin contact allows absorption through intact skin, and accidental ingestion is the third route, mainly in the case of improper transfer or storage in food containers. Because of these routes, ventilation and personal protection are the primary controls.
Symptoms of Overexposure
Inhalation of high vapor concentrations can cause coughing, shortness of breath, chest tightness, headache, and dizziness. Skin contact leads to redness, dryness, and irritation, while eye contact causes stinging and tearing. In serious cases of ingestion or very high vapor exposure, drowsiness and reduced coordination may occur. If symptoms develop, move the person to fresh air, remove contaminated clothing, and seek medical attention.
Safe Handling and Storage Guidelines
Keep isobutanol away from heat, sparks, and open flames; it has a closed-cup flash point around 28 degrees Celsius.
Use in well-ventilated areas and avoid breathing vapors.
Wear protective gloves, safety goggles, and protective clothing when handling.
Store in tightly closed containers, separated from strong oxidizers.
Do not eat, drink, or smoke while handling the chemical, and wash hands after use.
Frequently Asked Questions
Is isobutanol toxic? It is one of the least toxic butanol isomers, but it is harmful if swallowed and can irritate the eyes, skin, and respiratory tract at high exposure levels.
What is the CAS number of isobutanol? The CAS number is 78-83-1, and the molecular formula is C4H10O.
How can isobutanol enter the body? Through inhalation of vapors, skin contact, or accidental ingestion.
What symptoms can isobutanol exposure cause? Coughing, shortness of breath, chest tightness, headache, dizziness, and irritation of the eyes, skin, and respiratory tract.
How should isobutanol be stored? In tightly closed containers, away from heat and ignition sources, in a cool, well-ventilated area.