O-Cresol came onto the industrial scene during the rapid expansion of chemical processing in the late 1800s. Early on, factories used coal tar distillation to isolate cresols, including O-Cresol, and chemists soon noticed it did more than just sit in a beaker. From the start, this compound became crucial to producing disinfectants and antiseptics. By the 20th century, demand grew with the rise of synthetic flavorings, dyes, and plastics. The historical record makes it clear: every decade brought a fresh reason to refine cresol production. The focus kept shifting from basic chemical needs to specialty products for ever-growing industries—pharmaceutical firms, agrochemical giants, electronics makers, even perfumeries. This adaptability under pressure pushed research forward in technical standards, process safety, and downstream modifications.
O-Cresol, or ortho-cresol, falls in the family of methylphenols. It looks like colorless to pale-yellow crystals or oily liquid at room temperature, giving off that characteristic tar-like, medicinal odor. Plants and manufacturing units run at large scales to supply global demand—O-Cresol forms a backbone chemical for making herbicides (like MCPA), antioxidants (such as BHT), and various resins. It doesn’t play a background role; it drives several chemical chains and product lines. Sometimes, it even makes its way into consumer products, in trace or processed forms, showing the reach of this single-molecule actor.
Working with O-Cresol, you notice a strong, sharp smell fills the lab. The melting point lands just above room temperature, around 31°C, while the boiling point (around 191°C) keeps things interesting for distillers and safety teams. O-Cresol dissolves well in alcohol and ether but only partly in water. Its chemical structure, with that methyl group hugging the benzene ring, gives it a mix of reactivity and stability. That setup shapes everything from how it reacts with strong acids, oxidizers, and alkalis to its risk profile and environmental persistence.
Producers, driven by market standards and regulations, assign stringent technical grades to O-Cresol—usually above 99% purity for industrial uses. Labels cite batch numbers, purity, water content, and common impurities such as m-cresol and p-cresol. Containers must bear hazard icons, GHS identifiers, and specific handling instructions to stay in compliance. Every legitimate shipment comes with certificates showing that chemical fingerprinting and quality assurance checks have taken place, especially for pharma and agrochemical manufacturing.
O-Cresol production draws from both synthetic and natural routes. The classic process remains methylation of phenol or separation from coal tar. Large producers run catalytic alkylation, tuning out undesired isomers with selective catalysts. At smaller scales, laboratories might rely on demethylation or extraction from tar, but for volume, industry leans on continuous processes with recycling loops to push yields higher. These chemical plants opt for robust equipment crafted to withstand corrosives, running at elevated temperatures and pressures, always tuned for energy-use balance and product consistency.
Once you’ve worked with O-Cresol in a synthetic lab, it’s clear it isn’t content to sit idly by. Its ortho-position methyl group boosts reactivity for further substitution and oxidation. Chemists convert it to esters, ethers, aldehydes, and acids—each step opening up new applications. For example, process chemists target O-Cresol for phenoxy herbicide precursors or tweak the ring for custom antioxidants. The compound can withstand sulfonation, nitration, and halogenation, which is why it’s considered a Swiss Army knife for downstream chemistry. Engineering these transformations means deeper margins, and the industry knows how to prioritize processes that cut waste and cost.
O-Cresol goes by multiple names. Ask a supplier or a chemist, and you’ll hear ortho-cresol, 2-methylphenol, or sometimes just “cresylic acid (o-).” Regulatory filings and material safety data sheets often list CAS number 95-48-7, locking in global traceability. Marketed products don’t always wear their scientific names; formulas for solvents, disinfectants, or chemical intermediates might just say “cresol derivatives,” but the technical core stays the same.
Handling O-Cresol isn’t like stocking sugar or sodium chloride. Contact can burn skin, harm eyes, and cause respiratory distress. Frequent contact leads to systemic toxicity, so workplaces adhere to tight protocols. Operators gear up with gloves, goggles, chemical-resistant overalls, and real-time ventilation. Industry guidelines require spill kits, emergency showers, and well-documented training. The global supply chain must observe not just OSHA and EU REACH standards, but community-level rules for transport, storage, and waste. These aren’t suggestions—they’re enforcement priorities, demanded by workers and communities who live near chemical plants.
Every time you pick up a crop-protection product, synthetic flavoring, or engineered plastic, you encounter the long reach of O-Cresol chemistry. Agrochemical producers rely heavily on it to build herbicides. It serves as a stabilizer and antioxidant in rubbers, plastics, and lubricants. Evolving electronics require cresol-based resins to enhance printed circuit boards and adhesives. Pharmaceutical research teams pin their hopes on derivatives for everything from anesthetics to microbicides. This means the market for O-Cresol grows right alongside global infrastructure, medicine, and the food supply chain.
Scientific groups and manufacturers keep hunting for safer, greener pathways. Over the past decade, R&D has zeroed in on reducing emissions, improving catalysts for cleaner methylation, and recovering O-Cresol from bio-based sources. Universities and startups don’t just look for higher purity—they want processes that cut hazardous byproducts, lower energy needs, and boost worker safety. Modern analytics, like mass spectrometry and advanced chromatography, let researchers track contamination and optimize each batch faster. These research lines promise better environmental footprints and make life easier for downstream processors.
Reports on O-Cresol’s toxicity keep piling up, for good reason. Prolonged exposure damages vital organs and nervous systems. Acute effects pop up with respiratory, dermal, or oral contact—dizzy spells, nausea, and skin irritation. Lab animal studies confirm high-dose problems: liver, kidney, and brain impacts, prompting agencies like the EPA, CDC, and ECHA to maintain strict exposure guidelines. Environmental scientists track persistence in soil and water, probing for breakdown pathways and uptake in plants and wildlife. Knowing these risks, regulatory agencies push for safer substitutes in select industries and broader workplace controls everywhere else.
As industry heads into tighter environmental controls and the bioeconomy gathers steam, O-Cresol’s future will demand adaptation. Synthetic biology unlocks routes to methylphenols starting from renewable sources like lignin. Demand isn’t fading—electronics, biodegradables, crop science, and green chemistry each offer opportunities for better, safer, and less resource-intensive approaches. Policy shifts and consumer awareness will shape which processes win investment and lab time. The chemical world has learned O-Cresol won’t lose relevance, but where and how it’s made could look very different a decade from now.
I grew up thinking most chemicals only lived inside dull textbooks. After years working in environmental consulting and keeping tabs on industrial sites, I realized how some compounds never quite leave our orbit. O-cresol stands out as one of those. It’s got a slight medicinal scent, almost hospital-like—a sharp reminder of its punch. Most people walk around with at least a little o-cresol in the background of their lives, even if they don’t see it.
O-cresol pops up across several industries. Chemical manufacturers use it as a building block for bigger things. Producers make it from coal tar or petroleum, and it goes straight into making disinfectants, resins, and certain pesticides. O-cresol helps shape products that end up in our homes and workplaces. It plays a big role in making antioxidants and preservatives, which keep lubricants and fuels from breaking down and growing thick and useless. I remember touring a lubricant bottling plant—the smell hit before the sight, and a chemical engineer pointed out the storage tanks that held this raw, smelly “magic helper.”
Health workers sometimes use cresol derivatives for antiseptics and cleaners. Years ago, a nurse friend told me she recognized the same sharp tang in older hospital cleaning fluids. The chemical’s ability to damage bacteria makes it valuable, though many facilities have switched to less harsh options over the years. O-cresol doesn’t show up as often in retail sanitizers now, but its legacy sticks around. Historically, it played a role in making certain wood preservatives and even some dyes. Researchers keep searching for better, less persistent substitutes, but o-cresol’s effectiveness locks it in place in some situations.
Not everything about o-cresol shines so brightly. I’ve seen firsthand how improper disposal leads to headaches for communities near manufacturing plants. Runoff or leaks can pollute water sources. O-cresol doesn’t break down easily, and after it enters the soil, it tends to stick around, threatening wildlife and groundwater. Studies published by the EPA confirm the chemical’s toxicity at certain concentrations, and regulators have responded by clamping down on disposal methods. In my consulting days, we recommended routine monitoring of water around chemical plants, pushing for better storage protocols. Preventing runoff seemed like a no-brainer, but getting budget for upgrades was often a fight.
Workers exposed to o-cresol risk skin irritation and breathing trouble. OSHA sets exposure limits, but people working with the raw material know to respect the smell and avoid direct contact. A chemical engineer once told me he trusted his nose—if he smelled the cresol in the air outside processing areas, it meant something needed fixing.
Technology shows promise for safer handling. Newer filtration systems and recycling approaches help facilities capture o-cresol before it escapes. Responsible companies have invested in secondary containment and real-time leak monitoring, staying ahead of violations. I’ve noticed more transparency in the industry, as watchdog groups and local communities keep the pressure on to avoid shortcuts. O-cresol’s story fits a wider pattern—a useful molecule that delivers real benefits, but only if humans respect the risks and keep safety front and center.
O-Cresol is a chemical you sometimes find in labs, factories, or facilities working with dyes and resins. It can seem like another job hazard, but this one comes with a sharp, medicinal odor and a real punch to your health if you skip precautions. Skin contact brings burns or blisters, breathing in its vapors can trigger headaches, dizziness, and long-term exposure messes with your liver and kidneys. Once, I leaned over a drum during routine maintenance without full respiratory protection, and my throat stung for hours. It’s a wake-up call you don’t forget.
O-Cresol moves fast on unprotected skin, so wearing chemical-resistant gloves—nitrile or butyl rubber, never latex—makes a real difference. A thick lab coat and goggles block random splashes, but a face shield helps, too, during pours or transfers. Good footwear means no open shoes. A co-worker ignored this rule, spilled a small amount, and ended up in the ER. Simple gloves and well-fitted eye protection shift a risky task back to plain old routine.
O-Cresol vapors hang in the air, especially during transfers or heating. I’ve worked spaces where one whiff lets you know the fume hood isn’t working right. It matters—overexposure doesn’t always hit right away, but the nausea and fatigue build up. Use fume hoods, or work outdoors if possible. In spots with lousy ventilation, a half-face chemical cartridge respirator becomes your best friend. Testing the air for cresol levels should never be skipped.
Leaving O-Cresol out or unlabeled brings more trouble than convenience. Store it in sealed, labeled containers, well away from acids, oxidizers, or open flames—the stuff catches fire easily. I’ve seen folks improvise shelves or leave bottles near heating vents. Temperature extremes warp containers or cause leaks, so a cool, dry spot works best. Spill kits and eyewash stations should always be nearby, ready for use.
In an accident, seconds count. After a splash, get to the safety shower or eyewash and rinse for at least 15 minutes. Call for medical help as soon as exposure happens—don’t hope symptoms fade away overnight. Staff should know the drill through regular training, not just dusty binders. I’ve sat in rooms where practice drills felt silly, but the day someone spilled a beaker across a bench, that knowledge paid off.
Policies and instructions only work if backed by a culture where staff look out for one another. People laugh about “PPE police,” but reminders save skin and careers. Ongoing education pays off. The best-run shops run spot checks, keep signage updated, and encourage workers to speak up about unsafe situations. In places where safety culture takes a back seat to speed, accidents multiply—and stories get written that nobody wants to tell.
Handling O-Cresol forces you to respect the material and your crew. Shortcuts rack up injuries and long-lasting health issues. With real-world safety habits, practical PPE, and solid training, the risk drops. Every person in the room shares that responsibility, from the new hire to the shop lead. In my experience, prioritizing safety isn't just a checkbox; it’s what keeps everyone coming back the next day.
O-Cresol pops up in lots of factories and laboratories. It’s a chemical used to make things like disinfectants, dyes, and resins. At home, most people never hear about it, but it isn’t far off from the kinds of compounds you’d spot on a bottle of household cleaner or in the air at a busy gas station. O-Cresol occurs naturally in coal tar, but industry pumps out way more than nature ever could.
Working in a lab with O-Cresol, I used to get reminders about skin protection all the time. Even a quick splash could leave skin red and burning. O-Cresol doesn’t mess around; it can plow straight through skin and stir up trouble inside the body. Health agencies, like the U.S. Environmental Protection Agency (EPA) and the European Chemicals Agency (ECHA), list it as a hazardous substance for good reason. High exposure—especially through skin—brings dangerous effects, including serious burns, liver damage, and nervous system problems. Only a small amount needs to sneak in for symptoms to show up.
Outside of factory walls, O-Cresol leaks into the environment if nobody’s careful. Spills and dumping can push it into rivers and soil. O-Cresol dissolves easily in water, which raises another red flag. Fish and tiny aquatic animals get hit hardest. Studies show even low levels can trigger gill damage and cramps in fish, eventually leading to death if exposure continues. Because it breaks down gradually, O-Cresol sticks around just long enough to impact ecosystems downstream.
In the air, factories release O-Cresol during chemical manufacturing and poor waste handling. Once airborne, people near these sites report nausea, headaches, and throat irritation. Local kids—the most vulnerable in any community—feel the consequences sooner than healthy adults.
Fixing the O-Cresol problem calls for a team effort. On the shop floor, safety gear protects workers, but rules only work if everyone pays attention. Scrubbing the air with carbon filters and making sure waste doesn’t spill into drains are tried and true tactics. Factories with spill records usually face higher fines and stricter oversight, which helps push up standards.
On a broader scale, public agencies enforce stricter limits and regular monitoring at facilities using O-Cresol. The EPA, for instance, names O-Cresol on hazardous lists that set legal limits for how much can end up in air and water.
Communities living near manufacturing plants benefit the most from learning about chemicals like O-Cresol. Parents asking tough questions at public meetings push companies to manage chemicals with more care. Independent testing and real-time monitoring make sure unsafe leaks come to light quickly instead of years down the road. Preventing O-Cresol leaks and spills demands more than talk; it takes real investment in both equipment and training, along with clear consequences for breaking safety rules.
O-Cresol stands as a reminder that some chemicals, even ones used far from home, can show up in unexpected places. Simple steps—following laws, monitoring pollution, and giving workers and neighbors a say—cut the risk for everyone.
O-Cresol might seem like just another compound on a chemist’s shelf, but it has shaped products and production lines across industries, affecting lives in unexpected ways. As someone curious about the building blocks of everyday materials, I see o-cresol’s formula stamped into much more than textbooks. Every time a cleaning product does its job or a synthetic resin holds together under stress, o-cresol quietly leaves its fingerprint.
The formula for o-cresol: C7H8O. This gives you seven carbon atoms, eight hydrogens, and an oxygen. It’s a methylphenol—put simply, a phenol ring with a methyl group clinging to the ortho position. That position matters. Small shifts in where you add side groups can change chemical behavior. O-cresol’s structure means it acts just a bit differently from its siblings, m-cresol and p-cresol, which helps decide which kinds of reactions it will take part in.
Anyone who’s handled phenolic disinfectants can recall the sharp odor that lingers after scrubbing a countertop. O-cresol gives those products a punch—strong disinfectant capabilities stem from its phenol heart. In fact, manufacturers have leaned on cresols for decades to punch out microbes where milder cleaning agents fail. Workers in wood preservation and pesticide production also know cresol by the way it clings to memory long after a shift ends.
Beyond cleaning, C7H8O shapes the world of plastics and resins. O-cresol helps bind layers in plywood, insulate electronics, and keep materials stable under heat. Touch a rugged circuit board or the laminated surface of a kitchen counter—manufacturers may have built those surfaces stronger with cresol-based resins. Glassbonded semiconductors and certain adhesives still rely on the properties this molecule offers.
I’ve read reports connecting cresol exposure with headaches, skin irritation, and even poisoning if mishandled in large amounts. Workplaces using o-cresol often put controls in place—good ventilation, personal protective equipment, and airtight storage tanks. According to the U.S. Occupational Safety and Health Administration, limits on o-cresol exposure reduce risks for workers. These real-world steps buffer against situations where production needs clash with health concerns.
Regular people may not face high doses in daily life, but disposal methods still make a mark. Incomplete treatment of industrial waste risks cresol slipping into water supplies. Fixing this doesn’t start in some distant regulatory agency; it starts with plants adopting better cleanup, tighter leak monitoring, and frequent soil and water testing. Nothing beats transparency. Communities living near facilities deserve frequent updates, honest reporting, and a way to voice concerns early on.
Understanding C7H8O doesn’t end with memorizing a formula. O-cresol captures the story of how one compound, with its simple ring and side group, keeps finding new uses. The world’s hunger for stronger adhesives and tougher plastics shows no sign of slowing, but cleaner chemistry can match that pace. By following facts, listening to personal accounts in the workplace, and holding companies to strict safety standards, society can keep moving forward—balancing progress with public health for everyone who shares the air and water.
O-Cresol rarely makes the headlines but it’s one of those chemicals that demands respect. Used in everything from disinfectants to chemical manufacturing, o-cresol lands in workplaces where mistakes can have severe effects. Its fumes irritate the nose and throat, and liquid contact stings skin or eyes. Breathing high levels can lead to headache, dizziness, or worse. Anyone who has cleaned up a spill will tell you—this isn’t something to leave lying around.
Even a seasoned lab worker respects o-cresol. A steel drum or a tightly sealed amber glass bottle, clearly labeled, keeps accidental exposure down. Avoid plastic containers: o-cresol chews through some plastics and can start to loosen lids or break down gaskets. Rooms for storage stay cool, dry, and well-ventilated, locked away from anyone not trained to handle hazardous chemicals. Heat and open flames stay out; vapor buildup risks an accident or a fire.
Every storage area needs a chemical-resistant spill kit and easy access to safety showers and eyewash stations. Tracking who accesses o-cresol stops unauthorized handling and reduces risk. Using personal experience, I’ve seen near-misses when someone stored bottles near strong acids; one knock led to a gassy mess and several days of cleanup. Keeping incompatible chemicals apart matters more than people realize.
O-cresol doesn’t belong down the drain. Local wastewater plants can’t filter it out, so it ends up in rivers and groundwater, endangering fish and drinking water. A waste hauler specializing in hazardous material offers the best solution. They know how to collect, label, and safely transport the chemical to a treatment site. Incineration at controlled temperatures breaks down o-cresol, preventing harmful byproducts.
Small-scale users sometimes believe neutralizing o-cresol with bleach or strong oxidizers handles disposal. This practice often creates even nastier compounds, which linger longer in the environment. Rushing disposal trades short-term convenience for a long-term problem.
Anyone handling this chemical benefits from training. Even simple rules—keep lids sealed, check labels twice, work in a fume hood—save money and health. Storing safety data sheets within reach and holding regular safety briefings makes a measurable difference. Lab managers can encourage honest reporting of spills and near-misses instead of hiding mistakes, creating an environment where people look out for each other.
The EPA, CDC, and OSHA maintain current guidelines. Checking these resources steers companies away from potentially disastrous shortcuts. I’ve worked in a shop where procedures lagged behind legal requirements, and all it took was a surprise audit and one failed safety check to shut things down for weeks.
O-cresol offers many practical uses but comes with serious baggage. Proper storage and disposal routines protect both workers and the communities outside plant walls. Regular training, the right equipment, and a focus on responsible actions create a safer environment. Nobody ever regrets double-checking a chemical before use or calling a professional to handle disposal. They only regret the mistakes that follow carelessness.
| Names | |
| Preferred IUPAC name | 2-Methylphenol |
| Other names |
1-Hydroxy-2-methylbenzene 2-Cresol 2-Methylphenol ortho-Cresol |
| Pronunciation | /ˈəʊˌkriːsɒl/ |
| Identifiers | |
| CAS Number | 95-48-7 |
| Beilstein Reference | 1365070 |
| ChEBI | CHEBI:13215 |
| ChEMBL | CHEMBL14070 |
| ChemSpider | 506 |
| DrugBank | DB03793 |
| ECHA InfoCard | 100.031.385 |
| EC Number | 200-404-4 |
| Gmelin Reference | 821 |
| KEGG | C01432 |
| MeSH | D017174 |
| PubChem CID | 6997 |
| RTECS number | GO6300000 |
| UNII | K3BPI29E9O |
| UN number | UN2076 |
| CompTox Dashboard (EPA) | O-Cresol: "DTXSID0027866 |
| Properties | |
| Chemical formula | C7H8O |
| Molar mass | 108.14 g/mol |
| Appearance | Colorless to yellowish liquid with phenolic odor |
| Odor | Phenolic |
| Density | 1.05 g/cm³ |
| Solubility in water | slightly soluble |
| log P | 1.94 |
| Vapor pressure | 0.11 mmHg (25°C) |
| Acidity (pKa) | 10.26 |
| Basicity (pKb) | 10.29 |
| Magnetic susceptibility (χ) | -67.5·10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.543 |
| Viscosity | 11.8 cP (20°C) |
| Dipole moment | 1.55 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 110.0 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | −159.7 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -3532.8 kJ/mol |
| Pharmacology | |
| ATC code | D08AE04 |
| Hazards | |
| GHS labelling | GHS02, GHS06, GHS08 |
| Pictograms | GHS02,GHS06,GHS08 |
| Signal word | Danger |
| Hazard statements | H226, H301, H311, H314, H331 |
| Precautionary statements | P261, P280, P302+P352, P305+P351+P338, P310 |
| NFPA 704 (fire diamond) | 2-3-0 |
| Flash point | 81 °C (178 °F; 354 K) |
| Autoignition temperature | 550°C |
| Explosive limits | 1.3% - 7% |
| Lethal dose or concentration | LD50 Oral Rat 2,070 mg/kg |
| LD50 (median dose) | LD50 (median dose): 2,000 mg/kg (rat, oral) |
| NIOSH | K08670 |
| PEL (Permissible) | PEL (Permissible Exposure Limit) of O-Cresol: "5 ppm (22 mg/m3) |
| REL (Recommended) | 5 ppm |
| IDLH (Immediate danger) | 250 ppm |
| Related compounds | |
| Related compounds |
Phenol p-Cresol m-Cresol Thymol Guaiacol |
