Traced back to early organic chemistry labs of the nineteenth century, 2-Butanol didn’t jump out as the star player among alcohols. Chemists discovered it while exploring how starches and sugars could morph into new carbon frameworks by fermentation and distillation. By the turn of the twentieth century, simple distillation techniques made it more accessible. Industrial-scale synthesis took off as demand for solvents climbed in paints and rubber manufacturing. Petroleum refining soon provided an abundant way to make 2-Butanol through hydration of butenes. Historical patents and journal entries show how researchers, motivated by the shortcomings of earliest alcohol-based fuels and solvents, kept circling back to branched chain alcohols for their unique set of properties.
2-Butanol goes by several common names: sec-Butanol, butan-2-ol, and secondary butyl alcohol. These names crop up on chemical manifests everywhere from industrial cleaning suppliers to labs studying bioplastics. I have seen bottles labeled simply "sec-BuOH" on shelves in university stockrooms, often sitting between ethanol and tert-butanol. 2-Butanol stands out because its secondary alcohol group brings just enough steric bulk to influence reactivity, solubility, and volatility, marking it as a useful middle ground between straight-chain and more highly branched butanols in formulations.
2-Butanol appears as a colorless liquid, with a pungent but mild odor compared to isopropanol or tert-butanol. At room temperature, its boiling point stays close to 100°C, low enough to allow ready removal by evaporation yet stable enough to mix into all sorts of solutions. Its density hovers around 0.81 g/cm³, lighter than water but denser than some hydrocarbons. The alcohol dissolves well in water and most common organic solvents. On paper, 2-butanol distinguishes itself by a moderate vapor pressure and a flash point of about 24°C, which brings some flammability hazard but keeps it manageable in standard chemical handling protocols. Its secondary hydroxyl group supports oxidation, dehydration, and esterification without the vigorous reactivity of primary alcohols, making it a flexible choice as a synthetic intermediate or solvent.
Suppliers provide 2-butanol in grades that range from high-purity analytical standards to bulk industrial solvents. Labels on canisters show CAS numbers, purity (usually upwards of 99%), and key hazards like flammability (GHS02) and irritation (GHS07). Material Safety Data Sheets (MSDS) spell out limits for workplace exposure, recommend using splash-proof goggles, and stress good ventilation. Regulatory labeling sticks to clarity about chemical makeup, storage requirements, and transportation codes like UN 1120 for shipping.
Today, almost all commercial 2-butanol comes from the hydration of n-butene sourced from petroleum refining. Catalysts—often sulfuric acid or phosphoric acid on a solid support—convert the alkene to the alcohol with high selectivity. Early processes in labs used reduction of methyl ethyl ketone with sodium amalgam. In biorefineries working with fermentation, Clostridium strains offer a green route by breaking down sugars, but the yields remain lower than petrochemical synthesis, so this approach stays limited to specialty markets or academic research.
2-Butanol plays a key role in dehydration reactions, making methyl ethyl ketone after catalytic oxidation, a building block for plastics and rubber. Chemically, it joins as a feedstock in manufacturing esters like sec-butyl acetate, which finds its way into lacquers and coatings. Reacting with strong acids strips away the water to yield butene isomers. Oxidation steers toward ketones, and reduction doesn't shift the structure much, so synthesis flows tend to emphasize group modifications rather than deep changes to the backbone. In the lab, 2-butanol provides a moderate base strength and acts as a phase-transfer catalyst in some organic protocols.
Looking across chemical catalogs, you encounter “sec-Butanol,” “butan-2-ol,” “secondary butyl alcohol,” “2-hydroxybutane,” and occasionally “s-Butyl alcohol.” These terms refer to the same backbone structure, and labeling varies by manufacturer or region. Some older texts reference it using its systematic IUPAC name, but most industrial packaging sticks to “sec-Butanol.”
Anyone handling 2-butanol knows to keep it away from sparks and open flames, since its flash point brings a real risk of fire in poorly ventilated areas. Prolonged skin contact dries out tissue and causes cracking, sometimes even numbness. Inhalation of the vapors may give rise to dizziness or headaches, especially in closed spaces, so local exhaust ventilation matters. Safety guidelines from OSHA and European standards place occupational exposure limits at 150 ppm. Good storage practice means keeping drums sealed and grounded, in chemical flammable cabinets far from acids, oxidizers, or direct sunlight.
Paints, coatings, and inks have long relied on 2-butanol’s solvency and volatility. It functions as a coalescing agent, easing pigment dispersion and boosting drying times without gelling or separating. In pharmaceuticals, it serves as an intermediate in active compound synthesis, its moderate polarity offering unique extraction profiles. I have seen 2-butanol in soil and water extractions for environmental testing labs, pulling organics from complex samples. Even in agrochemicals and perfume bases, its blend of volatility and reactivity lets formulators tweak and extend lifespans or evaporation rates for active ingredients.
R&D teams keep probing the greener synthesis of 2-butanol, aiming for lower carbon intensity. Metabolic engineering lets biotech teams edit bacteria to yield higher titers of 2-butanol via fermentation, but these processes lag behind petro-derived methods in cost and throughput. Analytical chemists explore how 2-butanol assists as a sample preparation reagent for chromatography, or as a chiral modifier in separation science, thanks to its stereochemical centers. Chemists also test custom derivatives in polymer chemistry, linking the secondary alcohol into cross-linking agents for specialty plastics or adhesives where specific molecular architectures dictate performance.
Toxicologists have studied 2-butanol for decades, tracking acute and chronic effects. It carries a relatively low acute toxicity via ingestion or skin exposure compared to shorter-chain alcohols, but larger doses stress the central nervous system like other small alcohols, slowing reactions and coordination. Chronic occupational exposure, especially inhalation over years, has prompted long-term health monitoring in solvent-heavy industries. Researchers find no strong carcinogenic signals, but prolonged absorption dries and inflames tissues. Regulatory agencies require labeling that draws attention to both short-term symptoms and long-range overexposure risks, key in settings like paint shops or labs where exposure risks run higher than outdoors.
Prospects for 2-butanol look tied to both petrochemical and bio-based industries. Solvent demand in coatings, adhesives, and specialty chemical manufacture stays strong. Researchers watch for breakthroughs in biosynthetic routes, like genetically modified Clostridia capable of higher yield fermentations. Renewable routes to 2-butanol could tie into circular economy projects, using waste starches or lignocellulosic feedstocks. In analytical chemistry, chiral derivatives of 2-butanol may boost efficiency in separating enantiomers for pharmaceuticals, unlocking better drug formulations and delivery systems. Whether from a barrel or a bioreactor, 2-butanol remains a backbone of industrial and research chemistry, closely watched and carefully handled by those who know its potential and risks.
2-Butanol, also called sec-butanol, finds a place in many chemical plants and labs. Its story doesn’t show up on most people’s radar, but it impacts a surprising number of products and processes. I came across 2-butanol while working in a paint and coatings supply warehouse. We handled it daily, mixed it, and got to know its strengths and its quirks. It’s best known as a solvent and not something you’d use at home, but industry relies on it in several ways.
Countless paints, inks, and adhesives turn to 2-butanol for help. In the paint world, workers want consistent flow and smooth coverage. 2-Butanol blends well with other solvents, cutting through thick residues without harsh fumes or sticky leftovers. Its volatility also means the solvent dries at a steady rate, which keeps surfaces from getting tacky or uneven. Anyone who’s painted a room knows how much a good solvent can improve the job. Out in the field, it’s valued for thinning coatings and cleaning spray equipment between uses.
Factories and chemical engineers use 2-butanol as a building block for other substances, especially methyl ethyl ketone (MEK). MEK gets used in everything from plastic welding to cleaning electronic parts. Think of 2-butanol as a stepping-stone, providing a key part for bigger and more complex molecules. I learned that in plastic manufacturing, workers count on MEK for fast evaporation and strong adhesive properties, both possible because of the chemistry built off 2-butanol.
Fine chemical producers look to 2-butanol as an intermediate in pharmaceuticals. Drug companies rely on it to assemble molecules for medicine. While you won’t find it in tablets themselves, it helps during synthesis. Its presence in some research labs means plenty of chemists have stories of late nights working with the solvent, balancing the need for purity with safety. From experience, lab safety officers focus on ventilation and proper handling, since high concentrations can overwhelm your senses and pose health risks.
The food industry tags 2-butanol as a flavor enhancer and an ingredient in fragrances. Most uses stay within low concentrations. Aromas in processed products get a boost from this compound. Modern manufacturing depends on specific flavor notes, which can be tricky to replicate naturally during mass production. Companies turn to 2-butanol for consistent results that keep foods tasting the same from batch to batch.
Working with 2-butanol comes with responsibility. Shippers mark its containers as flammable. Inhaling too much or spilling the liquid can create headaches, dizziness, or worse. Factories must invest in good ventilation, personal protective equipment, and strict handling rules. Based on my time in chemical logistics, accidents come not just from big spills but also from lax procedures. It pays to slow down, double-check, and keep things organized to avoid emergencies.
People have raised concerns about volatile organic compounds and their effects on air quality. Regulation has begun to push industries toward safer and greener alternatives, especially where consumer-facing products come into play. Biobased solvents have begun to challenge traditional chemicals, 2-butanol included. Still, its role hasn’t faded; labs and manufacturers depend on it for reliability. Companies investing in better safety training and seeking state-of-the-art containment methods can protect both workers and the environment, all while keeping output levels high.
Walking into a hardware store, the smell of chemicals floats past from the paint section. 2-Butanol is right there in a few of those cans, finding its way into solvents, cleaners, and sometimes the odd manufacturing process. It’s a clear liquid with a faintly sweet scent, and it dries up quickly. Most folks outside a lab probably haven’t heard about it, but people run across it more than they realize, especially in industries that shape plastics, flavors, or pharmaceutical agents.
I’ve worked with various lab chemicals, and it’s always worth remembering that 2-butanol isn’t as gentle as it seems. Breathing in its vapor brings headaches, dizziness, and throat irritation. It travels through the lungs and starts messing with the nervous system faster than many expect—drowsiness, lightheadedness, even lack of coordination after enough exposure. If spilled on skin, there’s a risk of redness or burning. Eyes go red and watery with just a few drops. Swallowing it? Nausea, vomiting, and sometimes symptoms that feel like a bad night out, but worse. Chronic exposure—working for years in poorly ventilated shops—raises discomfort levels, and it can wear away at health.
OSHA calls for limiting exposure to 100 parts per million in workplace air over an eight-hour day. That’s not a lot. Take off your respirator or gloves for a few minutes and it can add up, especially in unventilated spaces. Fire also joins the party. 2-Butanol ignites easily, with vapors that can spread flames fast. A dropped rag or spill catches fire much quicker than most water-based cleaners, and smoke inhalation brings separate dangers for lungs and brain.
Digging into medical literature turns up animal studies where high doses brought kidney and liver problems—or worse. In human cases, as early as the 1940s, some workers in chemical plants suffered skin rashes, nausea, or tiredness. The National Library of Medicine lists it as a hazardous substance, not outright deadly, but nothing to dismiss. The body tries to break it down into smaller and less dangerous chunks, pushing it out through urine, but too much can overload internal systems. Long-term data doesn’t show direct links to cancer, though nervous system effects remain a concern after years of heavy exposure.
Gloves, goggles, long sleeves—these became my routine after a close call with a solvent spill. Working around 2-butanol needs fresh air moving through the room, and respirators make a real difference, not just for people with asthma or allergies. Storing it in flame-proof cabinets, away from hot tools or sparks, stops a lot of trouble before it starts. Today’s regulations come because too many workers suffered in decades past. Companies that use 2-butanol should train staff to spot spills, clean them up swiftly, and handle disposal in line with environmental laws.
Many chemicals slide under the public radar, as news cycles focus on bigger calamities. Yet, understanding what’s hiding in supplies at work or even the garage means fewer accidents and better choices. Employees in manufacturing and cleaning trades benefit most from solid education on these risks. No one should get caught off guard by fumes, fires, or the slow grind of chemical fatigue. The more we know about common solvents like 2-butanol, the safer workplaces and everyday life become.
2-Butanol, also called sec-butyl alcohol, draws interest from chemists and manufacturers alike for its notable blend of chemical and physical traits. Pouring out of the bottle, it reminds me of trying to clean paintbrushes in my college days—it lingers in the air, sharp and slightly sweet, carving out its presence long after the cap is screwed back tight.
2-Butanol boils at about 100°C, almost like water but with a faintly flammable edge. That puts it in a tight spot for storage and handling. Leave a container open near a warm plate, a noticeable amount will disappear quickly. Freezing this liquid takes the temperature down to -115°C. Unless you work in a lab chest freezer, you’ll never see it as a solid.
I’ve seen plenty of solvents, but 2-Butanol behaves with a special flair. It mixes with water in limited amounts—about 29 grams per 100 milliliters at room temperature. Try pouring a dash into a glass of water; it clouds, rather than vanishes. This partial solubility makes 2-Butanol handy for breaking down greases or pitching in as a co-solvent where pure water won’t cut it. Its density lands around 0.81 grams per cubic centimeter. That means if you shake a bottle, you’ll watch bubbles rise quickly—lighter than water, heavier than many hydrocarbons.
Look through a vial of 2-Butanol, and you see a colorless, clear liquid—a sort of transparency that gave me a false sense of safety the first time I handled it. Its refractive index, about 1.397, sits higher than water. Shining a light through, you’ll spot a bit more bend—a trick used in labs to check for contamination. This property finds use in specific chemical syntheses where pure optical quality really matters.
I remember watching a technician toss a match near a spill once. The flash was quick but unmistakable. 2-Butanol catches fire fast, and its vapors can light up even quicker. It burns with a faint blue flame, and produces poisonous fumes—definitely not the kind you want to breathe. OSHA lists it as hazardous, and it earns a flammable rating of 3 on the NFPA scale, which means storage needs a careful eye and steady hand.
The odor gives it away. A sweet, gasoline-like tinge that settles in the nose. A whiff is enough to steer most people clear. Drinking or inhaling 2-Butanol leads to rock-hard headaches, blurred vision, and worse. You find traces in flavorings, but always heavily diluted and tightly regulated.
Everything about 2-Butanol—its volatility, moderate solubility, transparent appearance—demands respect. In industrial settings, you often see strict guidelines for ventilation, spill control, and direct handling. Eye washes hang on the wall, gloves come standard, and solvent-proof aprons are part of the routine. I learned early that ignoring the gloves means a trip to occupational health. These steps matter. Proper labeling, secure storage, and clear emergency procedures prevent accidents and keep labs and factories running smoothly. If the right precautions stand in place, 2-Butanol brings utility to manufacturing, cleaning, extraction, and even cosmetics, while protecting workers and the environment from its sharp edge.
The conversation around solvent safety keeps growing. More companies double down on protective equipment and employee awareness. Folks are searching for greener alternatives, though 2-Butanol’s unique mix of traits keeps it in the game. As long as it’s handled right, this clear liquid keeps pulling more than its weight on the chemical shelf.
Many professionals working with chemicals have stories about solvents sneaking up on them. 2-Butanol fits that bill. It doesn’t announce itself with a punch to the nose like ammonia, but it slips quietly into the workflow. People use it for making cleaning agents, coatings, and even as a lab solvent. Still, 2-Butanol brings real health and safety concerns. Breathing it in or splashing it on skin can lead to headaches, dizziness, or irritation. There’s a risk for bigger trouble if enough vapor builds up: a spark can set off a fire fast. It is flammable and forms explosive mixtures with air, so keeping safety front of mind isn’t just good practice—it’s crucial.
Storing 2-Butanol isn’t as simple as putting it on a shelf. The right spot feels familiar: cool, dry, out of the sun, and away from open flames or heaters. This chemical doesn’t want warmth. As temperature climbs, vapor pressure rises, bottles sweat, and caps can loosen. Nothing ruins a workday like discovering a leaking solvent drum. Metal cans with tight-fitting lids or sturdy plastic containers hold up well, especially if they come with clear flammable material labels. Not every day gives a reminder to check seals or inspect labels, but taking a few extra minutes could save a lot of headaches—or worse, a workplace emergency.
No one enjoys cumbersome PPE. But there’s plenty at stake with 2-Butanol. Gloves matter, and not the cheap latex kind; nitrile or neoprene stand up better to this chemical. Safety goggles block the splashes that always seem to happen just before lunch. People sometimes forget to open windows or run the fume hood—ventilation makes a huge difference. Relying on that faint chemical smell is a risky bet, since levels can climb quickly without warning.
Pouring from bulk containers requires patience and steady hands. A funnel helps, but a slip can happen fast. Some folks try shortcuts, pouring over sinks or trash cans, but cleanup from a spill costs more time and money than doing it right the first time. Spills go straight to absorbent pads—never water. Water can spread the mess and bump flammable vapor into the air. The right approach involves spill kits and the discipline to grab them quickly.
Emergency planning separates responsible workplaces from reckless ones. Fire extinguishers for flammable liquids need to be in arm’s reach, with clear signage and easy instructions. Eyewash stations and showers aren’t just for the checklist—they save vision when accidents strike. Shelving sits low and secure, away from curious hands or anything that sparks. Training doesn’t stop at orientation; repeating the basics, sharing near-misses, and inviting questions keep everyone sharp. Hazards around 2-Butanol call for practical routines, not wishful thinking.
Storing and handling 2-Butanol well doesn’t demand heroic effort—it rewards basic diligence and the willingness to look out for others. The lessons shared between coworkers, the review of incident reports, and the improvements in storage setups all build a safer environment. A little consistency in following smart practices pays off. Real safety doesn’t grow from a pile of written procedures—it comes from building habits that everyone in the room respects and carries forward.
Ask any chemist about 2-butanol and they’ll probably shrug before telling you it’s just another secondary alcohol, but one with plenty of practical uses. It’s more than just a textbook example—it goes from chemical plants into adhesives, perfumes, and even ink production. Folks often want to know where it actually comes from. Here’s the thing: 2-butanol doesn’t grow on trees. Labs and factories use a few smart techniques to put it together, mostly starting with easy-to-get molecules and basic reagents. Chemists pick their paths based on cost, purity, and safety, usually after a hard look at what’s available nearby and how nasty the waste streams look.
If you’re working at scale, hydration of butenes wins out most days. Take butene—either the 1- or 2- form. Pass it through water with an acid catalyst, often sulfuric. Out comes 2-butanol and some friends, mostly 1-butanol and unreacted butenes. This is straightforward and lines up well with the petroleum industry. Refineries have butene streams ready for action. It’s fast, reliable, and the yields run high enough for serious production. There’s a catch: acid catalysis makes a good bit of waste acid and can create side products, so you need well-thought-out separation and recycling steps.
Another common method flips methyl ethyl ketone (MEK) into 2-butanol. You grab some MEK, treat it with hydrogen over a metal catalyst like nickel, and let reduction do the rest. This reduction process is extremely clean. Purification doesn’t create much headache, and you can run it in smaller reactors safely. Plenty of university labs and specialty producers like this approach since MEK is cheap, easy to transport, and doesn’t make a fuss if you store it right.
Anyone keeping an eye on green chemistry will be curious about biotechnological production. Some microorganisms, when coaxed with sugar and the right climate, churn out 2-butanol among other solvents. The yields haven’t blown anyone away yet, especially compared to more mature fermentation products. Still, this path matters for people demanding a renewable source or for markets restricting petrochemical origins. The real challenge right now comes from getting yields up, so the process can hope to compete on price. Some folks are optimistic, others point to issues like contamination and expensive downstream purification.
Giant plants might not break a sweat over water use or emissions if they’re hidden under old regulations, but smart operators now expect scrutiny. Sulfuric acid steps require care with spent acid, creating disposal headaches. Hydrogenation, powered by fossil or green hydrogen, draws attention to where your hydrogen comes from. Researchers and engineers keep tweaking catalysts and conditions to drop the energy intensity and raw material waste. Policy pressure on chemical producers mounts every year, so no method gets free rein to pollute or leave a mess for someone downstream.
It’s tempting to think chemical processes get set in stone, but every lab and plant manager faces a changing landscape. Feedstock prices, consumer demand for “greener” molecules, and local laws keep pushing new solutions. Smarter catalysts or bio-based pathways grab the spotlight in conferences, but getting those ideas out of journals and into reactors takes more patience—and investment—than most people expect. What matters, at the end of the day, is making the stuff safely, without draining the planet or poisoning neighborhoods that don’t have the luxury of saying no. Those questions stay just as relevant, no matter which road gets picked to synthesize 2-butanol.
| Names | |
| Preferred IUPAC name | Butan-2-ol |
| Other names |
sec-Butanol
sec-Butyl alcohol 2-Butyl alcohol methyl ethyl carbinol 2-hydroxybutane |
| Pronunciation | /tuːˈbjuː.tə.nɒl/ |
| Identifiers | |
| CAS Number | 78-92-2 |
| Beilstein Reference | 1713886 |
| ChEBI | CHEBI:28885 |
| ChEMBL | CHEMBL17564 |
| ChemSpider | 6707 |
| DrugBank | DB02157 |
| ECHA InfoCard | DTXSID6020224 |
| EC Number | 200-751-6 |
| Gmelin Reference | Gm:1108 |
| KEGG | C00474 |
| MeSH | D001943 |
| PubChem CID | 6560 |
| RTECS number | EL5425000 |
| UNII | 9LQS859L7L |
| UN number | UN1120 |
| Properties | |
| Chemical formula | C4H10O |
| Molar mass | 74.12 g/mol |
| Appearance | Colorless liquid |
| Odor | Characteristic |
| Density | 0.805 g/mL at 25 °C |
| Solubility in water | miscible |
| log P | 0.61 |
| Vapor pressure | 2.7 kPa (at 20 °C) |
| Acidity (pKa) | 16.1 |
| Basicity (pKb) | 15.1 |
| Magnetic susceptibility (χ) | -54.4 × 10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.399 |
| Viscosity | 2.9 mPa·s (at 20 °C) |
| Dipole moment | 2.89 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 157.3 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -320.2 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -2674 kJ mol⁻¹ |
| Pharmacology | |
| ATC code | R02AA20 |
| Hazards | |
| GHS labelling | GHS02, GHS07 |
| Pictograms | GHS02, GHS07 |
| Signal word | Warning |
| Precautionary statements | P210, P261, P305+P351+P338, P403+P233, P501 |
| NFPA 704 (fire diamond) | 2-2-0 |
| Flash point | 24 °C |
| Autoignition temperature | 422 °C |
| Explosive limits | 2.3–12.0% (in air) |
| Lethal dose or concentration | LD50 Oral Rat 2190 mg/kg |
| LD50 (median dose) | LD50 (median dose): Oral, rat: 2190 mg/kg |
| NIOSH | NIOSH: EO9100000 |
| PEL (Permissible) | 150 ppm |
| REL (Recommended) | REL-TWA 100 ppm (305 mg/m3) |
| IDLH (Immediate danger) | 1400 ppm |
| Related compounds | |
| Related compounds |
1-Butanol
Isobutanol tert-Butanol |
