Aniline chemistry shaped the dyes and pigments industry in the nineteenth century. Early workers like August Wilhelm von Hofmann expanded knowledge of aromatic amines, and sulfonated derivatives, including Aniline-2-Sulfonic Acid, led the way toward colorants that powered the textile boom. German and British chemists explored sulfonation in the search for brighter colors that held fast to fabric and paper. This exploration became vital during war times, pushing technology where exact molecular controls meant new possibilities for industry and agriculture alike. Every advance in purification or synthetic route meant a little more reliability for those relying on stable chemical supplies.
Aniline-2-Sulfonic Acid stands out as a versatile powdered compound with a broad spectrum of uses. The aromatic amine backbone, with a sulfonic acid group attached at the 2-position, offers a blend of solubility and reactivity that positions it for dye, pharmaceutical, and analytical work. As a building block, it shows up in industries with high expectations for purity and batch consistency—one customer may need it for azo dye intermediates, another for niche synthesis routes in custom labs. Any discrepancy in quality ripples into downstream products, so steady supply and reliable manufacturing matter a great deal in the long chain from bench to production.
A tan or off-white solid at room temperature, Aniline-2-Sulfonic Acid soaks up water and dissolves with ease, building aqueous solutions that chemists trust for predictable results. The compound carries the chemical formula C6H7NO3S, a molar mass that process engineers remember when setting up dosing equipment, and a melting point that shapes storage and handling. Steady reactivity under mild conditions sets it apart from more sensitive nitro compounds, but its aromatic nature, mixed with an acidic sulfonic group, opens routes for both electrophilic substitution and coupling reactions. People in production feel the bite of any missed step, so each property—solubility, crystallinity, even smell—matters in daily work.
Strict labeling and specification standards wrap every shipment—95% purity draws a clear line for downstream utility. Not every batch runs the same, so real-world labs chase batch records and retain control samples for months. Labeling captures CAS number and hazard identifications, so no one accidentally mixes it with an oxidizer or acids. Shelf-life, recommended storage temperatures, and precautions come stamped and checked, a process honed by years of near-misses and the need for traceability in case regulators knock on the door. Factory and shipping teams follow checklists that have grown more detailed each year, shaped as much by past errors as by regulatory pressure.
Sulfonation of aniline with sulfuric acid forms the main route to this compound. Operators balance temperature, acid strength, and timing, since over-sulfonation or incomplete reaction can torpedo the whole batch. They filter, wash, and sometimes re-crystallize, pulling off by-products like tar or unreacted starting material. What seems plain on paper—mix, heat, isolate—turns into a dance in real reactors. Yield loss, acid fumes, and maintenance downtime push production teams to innovate, squeezing extra percent from each run and keeping overhead manageable. In university labs, students learn this route as a rite of passage, just as factory chemists sharpen it for scale.
This acid opens pathways for dozens of modifications. Diazonium coupling ranks high among them, where a lab can create vivid azo dyes in one flask and subtle reaction intermediates in another. Sulfonic acids lend themselves to salt and ester formation, perfect for solubility tweaks or application-specific requests. I’ve watched teams push the boundary, blending it into multi-step syntheses of pharmaceutical precursors, or using it in analytical chemistry for ion-exchange processes. Dairy outflow can be tested for aminobenzenesulfonic acids, since these are good markers in water monitoring. Spend a day with a formulation chemist, and adaptations for purity, color, or reactivity start to feel less like esoteric knowledge and more like practical, critical skill.
Different labs and suppliers call it 2-Aminobenzenesulfonic acid, ortho-Anilinesulfonic acid, or Sulfanilic acid (though this last name often refers to the para- isomer). Catalog codes proliferate, and confusion can hit order desks that fill dozens of requests every hour. Communication between lab and purchasing grows smoother once both sides learn the alternate names. Regulatory databases cross-check these synonyms, especially as compliance grows tougher worldwide. Academic papers record older nomenclature in decades-old issues, so historical awareness helps folks avoid expensive mixups during re-orders or when comparing technical articles.
Everything starts with safe handling. Workers in plants suit up with gloves and eye protection, since dust inhalation brings headaches and skin exposure leads to irritation. Accidental splashes or spills mean immediate action—neutralizing agents always stand ready, and clean-up training happens yearly. Storage stays dry and segregated from strong oxidizers or reducing agents, since the combination can kick off unwanted side reactions. Safety Data Sheets get posted beside every workbench. On a personal note, strict attention to air handling and dust collectors has saved more than one technician from repeat allergic reactions or respiratory trouble down the line.
Colorant manufacture stands as its mainstay, feeding into textile, ink, and paper pigment streams. Beyond that, this material finds a home in specialty chemicals for rubber vulcanization accelerators, corrosion inhibitors, and concrete plasticizers. Every industry handler tracks tight specs and delivers reports with each shipment. In scientific research, this acid helps visualize complexation reactions or acts as a titration endpoint marker. Environmental laboratories measure it in river and industrial runoff as a signal of upstream production. Over the years, I’ve watched its role shift towards more nuanced analytical work, where trace detection demands high calibration and sample-to-sample consistency.
Academic and industrial researchers treat Aniline-2-Sulfonic Acid as a testbed for new dye molecules, new drug scaffolds, and innovative wastewater treatments. Every year, fresh papers show tweaks to the sulfonic position or introduce metal-complexation for catalysis. Teams have probed how to embed it in polymer chains or link it to peptides. These advances seldom come from isolated work; it’s the steady exchange between bench scientists, chemical engineers, and commercial partners that sets new directions. Funding for green chemistry has pushed labs to design milder reaction conditions and recycle mother liquors—both nods to environmental priorities reshaping chemical research.
Toxicology studies dig into acute and chronic health risks. Most labs report that oral or large skin exposures in animal models produce irritation, and some metabolites affect kidney or liver function. Chronic exposure links with hematological changes in laboratory animals, so strict guidelines limit daily handling. Regulatory bodies in Europe and North America update exposure thresholds and urge on-the-job monitoring, especially for new workers. It has always struck me that environmental fate—how quickly it degrades, which bacteria attack it—matters as much as acute toxicity. Downstream water monitoring and soil leach studies fill regulatory filings on both sides of the Atlantic.
Down the line, chemists and companies see prospects for this compound extending further into eco-friendly dyes, pharmaceutical intermediates that mesh with next-generation drug design, and as a trace analytical standard in pollution tracking. Supply chains will likely feel pressure to move towards greener synthesis, minimizing waste acid and focusing on energy-efficient reactors. AI-driven batch control and precise impurity monitoring could cut cost and boost confidence, reducing need for costly downstream reprocessing. Teams that focus on life-cycle analysis—every step from raw material to finished product—gain an edge with regulators and buyers who now ask hard questions about sustainability. These shifts might seem incremental, but they add up as industries learn from the past and look for smarter, safer, and more responsible chemistry.
Anyone who has walked through a chemical plant probably understands the importance of specialty chemicals like Aniline-2-Sulfonic Acid, 95%. People sometimes look at its name and think of complexity, but behind it sits an important role. This compound stems from the fusion of two familiar chemicals: aniline and sulfuric acid. Chemists use a targeted process to combine these, which means the final product shows up as a fine, often off-white solid, recognizable to workers by its distinct appearance and mild odor.
Industries making dyes have long relied on this acid. Many textile factories continue to source it as a key intermediate. The molecule’s structure lets it tie other fragments together, which helps lay the groundwork for azo dyes—think of the bold reds and vibrant blues in clothing and leather goods. From my own hands-on experience working in research, the most consistent push for quality color comes down to the stability of these raw materials. Sulfonic acid groups improve how well dye molecules hold onto fabric, which reduces color fading during washing. Over decades, the textile sector has invested heavily to lock in shade fastness. One way to make those gains is by controlling the purity of building blocks like this acid. At 95% purity, the process avoids too many unwanted byproducts, which gives textile factories more control over finished colors.
Not all uses follow dyes. Pharmaceutical labs find value in this acid as a starting point for complex molecules. Because sulfonic acids mix well with water and react readily with nitrogen-containing compounds, many medicine makers include this ingredient on their list of reliable starting materials. You see its fingerprints in drugs for pain relief, anti-inflammatories, and sometimes in antibiotics. Hospitals trace their inventory back to lab benchmarks, and that’s where consistent chemical supply matters. Any disruption in these specialty supplies can slow down how fast new medicines reach clinics.
Pigment factories depend on it for similar reasons. Artists’ colors, printer inks, even wall paints all come packed with synthetic pigments. Vibrancy and coverage improve when pigment molecules bind tightly with the sulfonic acid base—especially for yellows and reds. Over my years consulting with coatings manufacturers, I watched engineers test different combinations. The common thread: fewer impurities in their chemicals meant longer-lasting, more reliable hues on finished products.
Workers know this compound reacts with strong acids and bases. In plant settings, safe handling becomes a daily routine. At 95% concentration, spills can irritate skin or eyes, so good training and protective gear stand between workers and avoidable injury. Wastewater treatment also becomes crucial. Companies investing in modern scrubbers and effluent plants catch most of the potentially harmful byproducts. Regulation from environmental agencies keeps everyone honest. Factories facing fines if they let this chemical escape untreated often channel that pressure into building stronger safeguards. I’ve seen plants invest in multi-stage filtration and keep emergency showers close to production lines.
More labs are eyeing greener processes. Pushback from regulators and the public has nudged research teams to rethink synthesis routes—sometimes looking for ways to reuse spent acids or cut down energy use during manufacturing. Innovation often starts with small trials, but once proven, spreads to mainline production. Each upgrade means safer factories, less pollution, and a better product at the end. For anyone watching the intersection of chemistry, industry, and safety regulations, following where Aniline-2-Sulfonic Acid ends up paints a larger picture of the drive for responsible production.
Aniline-2-sulfonic acid doesn’t get much attention outside labs, but anyone who handles chemicals knows the rules for storage matter just as much as the formulas in the notebook. I remember my graduate school storeroom smelling faintly of vinegar and ammonia, a small reminder of what happens when bottles get mixed up or mishandled. It only takes one accident to appreciate why solid storage habits make all the difference.
Water changes everything for this acid. In the open air, even a little humidity can make a chemical cake or degrade. For Aniline-2-sulfonic acid, moisture invites clumping and then starts chemical changes you just don’t want. You lose the reliability of your material, and the next experiment could float right down the drain. That’s why it belongs in a tightly sealed container, kept away from sinks, steam, or anywhere damp air sneaks in.
Some folks think room temperature means any room with a door, but for this acid, “cool and dry” means down below 30°C and away from heaters, sunlight, or any spot where temperatures swing. I’ve seen labs where people stash supplies under open windows or right by radiators, forgetting a sunny afternoon can warm a shelf well past what’s safe. Chemical supply safety data sheets back this up: higher temperatures often speed up slow reactions, and nobody wants to play catch-up with unpredictable changes in their reagents.
Every time a bottle opens, the risk of contamination goes up. Scooping from a poorly labeled jar or using a wet spatula can leave traces behind that spoil the whole container. I learned my lesson early—never reuse scoops between different chemicals. For Aniline-2-sulfonic acid, cross-contamination with organic solvents or oxidizers piles on extra risks. Some chemicals react and release hazardous gases, or discolor, and good luck tracing the source after a crowded bench day. The best fix is labeling every bottle, using only clean dry tools, and building a culture where quick and careful have to go together.
Rooms without exhaust fans build up fumes. High shelves soon drop bottles. This acid belongs in a well-ventilated spot, away from acids, oxidizers, and flammables. I’ve worked in labs where corrosive shelves mixed with flammables let risks stack up. Some chemicals end up in secondary containers or storage cabinets because broken glass and mystery spills get ugly fast. It’s not just about following a guideline; it’s about real people getting home safe at the end of the day.
Protocols get you started, but habits keep you safe. Training every lab user means more than reading a sheet—it’s walking through the storeroom, testing the seals, and making sure you wouldn’t mind your co-worker grabbing the same bottle on your day off. Regulations exist, but sharing stories matters most: I’ll never forget the day someone stacked acids on a wooden shelf, and two weeks later, the shelf failed after a spill. The whole place shut down for a week.
A little time spent reviewing storage conditions saves a lot of trouble. Checking the temperature, spacing containers, labeling sharply, and never letting clutter build up means you’re less likely to look back with regret. The cost of new containers, dry shelving, or dedicated acid cabinets is nothing compared to the cost of emergency cleanup or lost experiments. Good storage for Aniline-2-sulfonic acid isn’t just about following steps—it’s about respect for the tools and people that make chemistry possible.
Aniline-2-sulfonic acid, 95% stands out as a common industrial chemical. It shows up in everything from dyes to pharmaceuticals, showing how science reaches into so many daily products. But working in a lab, I learned to treat certain fine powders with caution—and this compound belongs in that group. Many safety data sheets flag its hazards, especially for eyes and skin. Direct exposure sometimes leads to burns or irritation, and fumes can sting the nose or throat.
Exposure is a real concern. People often ignore the danger when handling familiar chemicals but skin contact might cause redness, swelling, or even blistering. Breathing in the dust or handling the acid carelessly increases the risk. Consider this real-world example: a colleague splashed a small amount while cleaning glassware. Gloves helped, but one missed spot on the wrist meant an itchy rash for days. The impact may seem minor, but a single lapse opens the door to injury.
Shifting to a bigger scale, chronic exposure leads to a buildup of health issues. Some studies have shown that repeated contact or inhalation can lead to respiratory irritation and, in rare cases, affect organs over time. This caught the attention of workplace safety boards, which set strict exposure limits. The National Institute for Occupational Safety and Health lists aniline derivatives among chemicals that deserve extra respect.
There’s another layer of risk beyond personal safety: what happens when the acid gets into soil or water? Chemicals like aniline-2-sulfonic acid do not break down easily. They stick around and might poison aquatic life. I remember a local river cleanup after a spill from an industrial site. Crews worked overtime sealing off contaminated sections and testing water, but the impact on fish stocks lasted for months.
Even small spills demand attention. Without careful storage, containers may leak. Once these chemicals move into storm drains, they threaten the water supply. Some municipalities restrict discharge limits and require companies to pre-treat wastewater before disposal. It's easy to forget just how much trouble one leaky drum can cause.
Experience teaches that personal protective equipment—goggles, gloves, and reliable ventilation—keeps risks low. Having a clear plan for storage and disposal matters just as much. Secure, labeled containers offer a simple barrier against accidents. Training workers to spot risks before trouble starts usually makes the biggest difference.
Replacing hazardous chemicals with safer options—when possible—leads to long-term gains. Certain dye manufacturers now seek alternatives or tweak processes to use smaller amounts. Less on the workbench means fewer accidents and less environmental damage in the long run. For people who still need to handle aniline-2-sulfonic acid, simple steps like clear labeling, prompt clean-up, and routine health checks mark a big improvement.
Nobody wants a chemical accident on their conscience or in their community. Clear rules around hazardous materials protect workers, families, and environments. Aniline-2-sulfonic acid, 95% delivers benefits in manufacturing but calls for respect, knowledge, and accountability. Practical action—built on science—offers real protection for people and the places they call home.
In laboratories and classrooms, Aniline-2-Sulfonic Acid makes frequent appearances, not just as an abstract chemical name but as a fundamental building block for synthetic chemistry and colorants. Its molecular formula, C6H7NO3S, captures a rich interplay of nitrogen, sulfur, and aromatic carbon, delivering properties that chemists and industries value for practical work.
Aniline-2-Sulfonic Acid’s structure traces back to a benzene ring—six carbons in a tight, planar loop, much like the base in regular aniline. At the heart of its chemistry, you’ll find an amino group (NH2) swapped in at position 2, paired directly across from a sulfonic acid group (SO3H). This small change in placement sparks big differences in behavior. For example, the sulfonic acid group boosts water solubility, controlling how easily it spreads through solutions or interacts in dye manufacturing. I’ve seen this firsthand in dye labs—switching various sulfonic acids onto aniline straight-away changes which fibers catch color and how lasting those hues become.
Industries stack pallets with Aniline-2-Sulfonic Acid not just for dye synthesis but for specialty plastics and some medicines. In dye works, its particular arrangement means the molecule plays nicely with other organic compounds, helping to lock vivid colors within fabric molecules. It doesn’t take long watching production lines to spot how a small tweak in chemical structure can lead to a batch passing or failing strict quality standards—contaminants above a certain percentage can kick start reactions you don’t want, driving up costs and rework. That 95% purity marker sets a line, separating practical, reliable batches from those that could create trouble downstream.
Aniline derivatives—including this one—often raise eyebrows due to health hazards. Consistent exposure without proper handling tools leads to skin sensitization, respiratory issues, and, in worst cases, toxicity. Working in small-scale labs and scale-up pilot plants, I’ve learned that safety showers, gloves, and chemical fume hoods aren’t optional extras—they’re frontline defenses. Regulations might pin requirements on paper, but day-to-day, keeping an eye on safety involves proper labeling, regular training, and setting up protocols for accidental spills.
Innovations in greener chemistry pull focus toward making and using molecules like Aniline-2-Sulfonic Acid with less waste. Efforts to reclaim catalysts, improve purification, and monitor effluent streams cut back on environmental load. Companies moving away from dumping untreated byproducts have real impact—those that invest in closed-loop systems dip into their profit margins at first but build longer-lasting brands and safer communities around their plants.
Industry doesn’t run on chemistry alone. Maintaining that 95% specification relies on constant checks—high-performance liquid chromatography (HPLC) shows up as a familiar tool, not just abstract technology. HPLC lets teams pick up trace impurities before they leave the plant. Experienced technicians know from routine runs that subtle changes in peak shape or retention time can clue them in to deeper problems, sometimes saving an entire shipment with a single test.
Efficiency, safety, and a molecule like C6H7NO3S all link back to everyday choices in labs, factories, and classrooms. The molecular formula tells part of the story, but the full picture rests on how people work with it, the standards they adopt, and the respect they give to both the opportunities and the risks it brings along.
Anyone who has worked in a lab remembers the sting of chemicals splashing just once. You learn quickly which bottles require real respect. Aniline-2-sulfonic acid isn’t the most alarming substance, but dropping your guard can land you trouble. It’s not rare to see skin irritation or a cough if the powder turns airborne or meets moisture. Having handled scores of powdered reagents over the years, I make no assumptions when new ones land on my work bench. Life in the lab gets safer when knowledge becomes routine, and old habits—goggles on, gloves snug, coat buttoned—become second nature.
Aniline-2-sulfonic acid’s appearance doesn’t set off alarms—its crystalline or powder form seems harmless. But labs have rules for a reason. This compound can irritate eyes, skin, and airways. Working dry, it stays tame. Add a splash, humidify the air, or spill a scoop, though, and acid burns aren’t far off. In my early years, wiping up a spill with paper towels led to a lesson: gloves protect more than just palms, and handwashing brings instant relief. Poor ventilation means breathing trouble, headaches, even dizziness, especially after several hours in close quarters.
Lab coats and nitrile gloves might seem basic, but these barriers block the most common routes for harm. Goggles shield against dust and accidental splashes. Only after days with sore hands or a cough growing worse did I learn that gear matters just as much as procedure. The Occupational Safety and Health Administration (OSHA) lists aniline derivatives among substances worth special attention. Safety Data Sheets do not exaggerate: splash-proof goggles protect you from eye redness and longer-term consequences. Good labs keep chemical-resistant gloves in bulk for a reason.
History in the lab proves how eye-wash stations near work spaces aren’t overkill. Wearing the right gloves—nitrile, sometimes butyl—saves more than time. A decent fume hood pulls away dust and fumes, and stores bottles at eye level rather than high shelves; I’ve seen spilled powders rain down with just a careless hand. Routine training keeps everyone alert and reinforces these habits. One careless moment, one bottle handled in a rush, turns a harmless task poorly.
Safe storage ranks high: the acid belongs in well-ventilated, cool spaces, sealed tightly. Clean benches after every use. Avoid piles of ragged gloves or open containers to minimize the risk of accidental contact. Dispose of all waste using authorized channels—never shortcut down the sink, no matter how diluted. Supervisors can encourage a real culture of caution. Schedule regular PPE checks, refresh spill-response drills, keep data sheets posted and up to date. People learn by repetition, but they remember by seeing colleagues walk the talk.
Mistakes happen most often with the most common chemicals. In labs where safety becomes culture and not just compliance, serious incidents drop off. I’ve seen colleagues step in, hand over fresh gloves, and point out a missing mask. Building habits around protective equipment does more than tick boxes for audits—it makes every day at the bench a little safer, for everyone down the line.
| Names | |
| Preferred IUPAC name | 2-Aminobenzenesulfonic acid |
| Other names |
2-Aminobenzenesulfonic acid Orthanilic acid o-Anilinesulfonic acid o-Aminobenzenesulfonic acid |
| Pronunciation | /ˈæn.ɪˌliːn tuː ˈsʌl.fə.nɪk ˈæs.ɪd/ |
| Identifiers | |
| CAS Number | 88-21-1 |
| Beilstein Reference | 2761030 |
| ChEBI | CHEBI:27841 |
| ChEMBL | CHEMBL2204913 |
| ChemSpider | 140703 |
| DrugBank | DB13984 |
| ECHA InfoCard | 100.004.431 |
| EC Number | 202-425-9 |
| Gmelin Reference | 75038 |
| KEGG | C06561 |
| MeSH | D014233 |
| PubChem CID | 8445 |
| RTECS number | BW6650000 |
| UNII | 4748HR7N92 |
| UN number | UN2581 |
| CompTox Dashboard (EPA) | DTXSID0029828 |
| Properties | |
| Chemical formula | C6H7NO3S |
| Molar mass | 173.20 g/mol |
| Appearance | Gray to beige crystals or powder. |
| Odor | Odorless |
| Density | 1.426 g/cm3 |
| Solubility in water | Soluble in water |
| log P | -1.5 |
| Vapor pressure | <0.01 mmHg (20°C) |
| Acidity (pKa) | 1.0 |
| Basicity (pKb) | 6.4 |
| Magnetic susceptibility (χ) | Diamagnetic |
| Dipole moment | 3.41 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 196.3 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -342.7 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -1359.7 kJ·mol⁻¹ |
| Pharmacology | |
| ATC code | |
| Hazards | |
| Main hazards | Harmful if swallowed. Causes severe skin burns and eye damage. Causes serious eye damage. May cause respiratory irritation. |
| GHS labelling | GHS05, GHS07 |
| Pictograms | GHS07,GHS05 |
| Signal word | Warning |
| Hazard statements | Harmful if swallowed. Causes skin irritation. Causes serious eye irritation. May cause respiratory irritation. |
| Precautionary statements | P261, P280, P305+P351+P338, P337+P313 |
| Autoignition temperature | > 635°C (1175°F) |
| Lethal dose or concentration | Lethal dose (Oral, Rat): LD50 = 2000 mg/kg |
| LD50 (median dose) | LD50 (median dose): Oral, rat: 1217 mg/kg |
| NIOSH | BS6400000 |
| PEL (Permissible) | Not established |
| REL (Recommended) | No REL established |
| IDLH (Immediate danger) | Not established |
| Related compounds | |
| Related compounds |
Aniline p-Aminobenzenesulfonic acid o-Toluidine-5-sulfonic acid Sulfanilic acid Benzenesulfonic acid |
