Ortho Toluidine
Ortho Toluidine — o-toluidine or 2-methylaniline — is the highest-volume of the three toluidine isomers and the workhorse amine behind rubber vulcanisation chemicals, azo dyes and pesticide and pharmaceutical intermediates. It is also a confirmed human carcinogen, and this page treats that fact as central rather than incidental.
Chelora Chemicals supplies o-toluidine to rubber chemical producers, dye houses and agrochemical formulators worldwide, in drums, IBCs and tank quantities, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 95-53-4
- IUPAC name
- 2-Methylaniline
- Molecular formula
- C7H9N
- Molecular weight
- 107.15 g/mol
- EC / EINECS
- 202-429-0
- UN Number
- 1708
- SMILES
- Cc1ccccc1N
- HS Code
- 2921 43*
* Confirm the exact HS heading with your customs broker — classification of toluidine isomers varies between destination tariffs.
What Ortho Toluidine is used for
Ortho Toluidine is aniline carrying a methyl group ortho to the amino group. That steric proximity between the methyl and the amine shapes its chemistry in ways that matter downstream: it is the entry point to a large family of rubber vulcanisation accelerators and antioxidants, a long-standing diazo component in azo dye and pigment manufacture, and — via chlorination and further chemistry — a precursor to several herbicide actives.
o-Toluidine is also, unambiguously, a known human carcinogen. The U.S. National Toxicology Program lists it as such, and IARC classifies it in Group 1. That classification is central to how every commercial user should plan handling, and we put it up front here rather than in the small print.
Why the isomer matters
The three toluidine isomers carry materially different hazard profiles, and a mis-substitution downstream is not recoverable:
- 2-Methylaniline / ortho toluidine (CAS 95-53-4) — this product. Methyl ortho to the amine. IARC Group 1 — a known human carcinogen — and the highest-volume isomer by far.
- 3-Methylaniline / meta toluidine (CAS 108-44-1) — the meta isomer, not classified as a carcinogen, used across a narrower dye and fine-chemical chemistry.
- 4-Methylaniline / para toluidine (CAS 106-49-0) — the para isomer, a solid at room temperature, carrying its own Category 2 carcinogenicity classification and heavy use in dye chemistry.
If your purchase order simply says "toluidine", quote us the CAS number and we will confirm the correct material before the order is placed. We supply all three isomers, as well as related chloroanilines, nitroanilines and anisidines — see our full product catalogue.
Appearance and handling character
o-Toluidine ships as a colourless to pale yellow liquid with a melting point around −24 °C, so it stays liquid through virtually every transport and storage condition worldwide. It is only slightly soluble in water and miscible with most organic solvents. Like other primary aromatic amines it darkens on prolonged exposure to air and light. Read the safety section carefully before planning any handling programme: the carcinogenicity classification should shape your controls from the outset, not be discovered at the goods-in door.
| Parameter | Typical value |
|---|---|
| Appearance | Colourless to pale yellow liquid |
| Assay (GC) | 99.0% min |
| Water content (KF) | 0.3% max |
| Colour (APHA) | 50 max |
| Total isomeric impurities | 1.0% max |
| Specific gravity | Reported per batch |
Important: the figures above are indicative of commercial grade material and are offered for planning only. The batch certificate of analysis is the governing document. If your process demands a tighter assay, a specific isomer limit or a colour ceiling, send us the specification and we will quote against it rather than against a generic grade.
| Property | Value |
|---|---|
| Physical state | Liquid at ambient |
| Melting point | ≈ −24 °C |
| Boiling point | ≈ 200 – 202 °C |
| Flash point | ≈ 85 °C (closed cup) |
| Relative density | ≈ 1.004 (20 °C) |
| Refractive index | ≈ 1.570 |
| Water solubility | ≈ 1.5 g/100 mL (25 °C) |
| Organic solubility | Miscible with alcohols, ethers & most organic solvents |
| Odour | Amine-like, aromatic |
Physical constants compiled from public reference data for CAS 95-53-4 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
o-Toluidine's largest historical outlet is rubber chemistry, with substantial secondary demand from dye, agrochemical and pharmaceutical manufacturers.
Rubber vulcanisation chemicals
The largest historical outlet. o-Toluidine is a building block for rubber accelerators and antioxidants used in tyre and technical rubber goods manufacture — chemistry that depends on a consistent, well-characterised feed amine.
- Accelerator & antioxidant intermediate chemistry
- Tyre and technical rubber goods sector
- Tight isomer limits usually apply
Azo dyes & pigments
Diazotised o-toluidine couples onto naphthol and acetoacetarylide components to build azo pigments such as the Fast Orange and Hansa-type series, giving shades distinct from those built on plain aniline.
- Diazo component in azo pigment synthesis
- Isomer purity shows up directly as off-shade
- See also meta toluidine
Agrochemical intermediates
o-Toluidine is a key starting material in the synthesis of several chloroacetanilide herbicide actives, where the ortho-methyl pattern is part of the target molecule's structure.
- Chloroacetanilide herbicide chemistry
- Custom agrochemical intermediate synthesis
- See our agrochemical intermediate range
Pharmaceutical intermediates
The 2-methylphenylamine fragment is used in several established pharmaceutical synthesis routes, including local-anaesthetic and other API chemistry built through amide formation and N-arylation.
- Amide, urea and sulfonamide formation
- Heterocyclic ring construction
- See also ortho anisidine
Fine & specialty synthesis
A well-characterised amine building block for custom amides, ureas, Schiff bases and ligand work under controlled, professional-use conditions where the ortho-methylaniline pattern is specifically required.
- Custom amide and urea formation
- Ligand and coordination chemistry
- Available in trial and laboratory quantities
Contract & scheduled supply
Rubber and agrochemical plants run to campaign, not to a calendar month. Most o-toluidine buyers want tonnage released against a production plan rather than in one shipment. We hold inventory and release it to your schedule.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply Ortho Toluidine
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no toluidine plant — and for a carcinogen-classified, specification-sensitive intermediate like this one, that independence works in your favour. We are never obliged to push you whatever a captive unit happens to be running that month.
Instead we place your order with whichever qualified producer best matches your assay, your isomer tolerance, your price point and your delivery window.
We keep a second qualified source on this line. When a plant goes down for maintenance or an environmental inspection, your campaign switches source rather than stalling.
- Specification read against the CAS first. We confirm you need 95-53-4 and not the meta or para isomer before we quote a price.
- Batch COA shared before dispatch. You approve the assay, colour and impurity profile against your own spec while the material is still in our warehouse.
- Carcinogen status stated up front. This material is an IARC Group 1 confirmed human carcinogen, and we say so at enquiry stage — not in the small print of a document pack that arrives with the goods.
- Pre-shipment samples for qualification. New account or new source, your R&D team runs a lab batch before the full quantity ever moves.
- Packing chosen for a flammable, carcinogenic liquid. Closed-transfer-compatible drums, IBCs or tank quantities — we plan the format with exposure control in mind.
- Export machinery handled in-house. Hazard classification, UN-approved packing, labelling, freight booking and customs paperwork are ours to manage.
- Consolidation onto one bill of lading. Ship o-toluidine alongside other intermediates from our range — one invoice, one shipment, one counterparty.
Packed the way your plant receives it
As a liquid amine with a carcinogen classification, o-toluidine is packed with closed transfer and minimal operator contact in mind. Tell us how it will be charged at your end and we will quote the format that suits your operation.
UN-approved steel or HDPE drums
The standard format for LCL shipments and for plants charging drum-wise through a closed pump-fed transfer.
IBC totes
Composite or steel IBCs for mid-volume buyers with mechanical, closed-loop unloading. Fewer container changes per tonne than drums, reducing exposure events.
ISO tank containers
Bulk liquid movement for high-volume buyers with dedicated closed-transfer receiving. The lowest landed cost per kilo and the fewest handling events at container scale.
Samples & trial packs
Laboratory samples in sealed glass or lined-steel containers, dispatched by courier so your R&D team can qualify the grade before committing to campaign volume.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to. Ocean, air and road freight arranged end-to-end with documentation filed before booking.
Campaign despatch
Rubber and agrochemical production runs to campaign. We hold contracted tonnage and release it against your production calendar instead of landing it all at once.
Handle this as a confirmed human carcinogen
This is the point on the page that matters most. Ortho toluidine is not only acutely toxic — it is classified by IARC in Group 1, "carcinogenic to humans", and by the U.S. National Toxicology Program as a known human carcinogen. In several jurisdictions that brings specific occupational obligations that go well beyond ordinary chemical handling. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document and should govern your risk assessment, PPE selection, exposure monitoring and emergency planning.
Classified hazards
H350May cause cancer.H301Toxic if swallowed.H302Harmful if swallowed.H319Causes serious eye irritation.H331Toxic if inhaled.H400Very toxic to aquatic life.
Hazard statements reflect the harmonised GHS classification commonly published for CAS 95-53-4, with carcinogenicity classed as Category 1B under CLP. IARC classifies o-toluidine in Group 1 — carcinogenic to humans. Supplier classifications may differ in detail; always read the SDS issued with your specific batch, and treat the carcinogenicity entry as the one that shapes your controls.
Spill & emergency orientation
Plan your response before the drum arrives, not after a valve leaks. The points below are orientation for your emergency planners — sections 4, 5 and 6 of the SDS are the authoritative instructions and should be posted at the point of use.
- Contain, do not hose to drain. The material is very toxic to aquatic life. Bund and collect spilled liquid into a labelled container; never wash it to a drain or watercourse.
- Eliminate ignition sources. As a combustible liquid, treat a spill area like any flammable-liquid incident — no naked flames, sparks or hot surfaces nearby.
- Assume skin absorption. Contaminated clothing is a continuing exposure route — remove it immediately and wash the skin thoroughly.
- Have the SDS with the casualty. Toluidines can cause methaemoglobinaemia, and the treating clinician needs the product identity and CAS number in hand.
- Record the exposure. For a Group 1 human carcinogen, most occupational regimes expect an exposure record to be created and retained. That is a decision for your EHS function, and it is easier made before an incident than after one.
Storage
- Cool, dry, well-ventilated store, away from direct sunlight, heat sources and ignition sources. Bunded floor to contain a drum or IBC failure.
- Keep containers tightly closed. Air and light drive the colourless-to-amber drift typical of anilines, and an open drum also picks up moisture.
- Segregate from oxidising agents, strong acids and acid chlorides. As a primary aromatic amine it reacts exothermically with acylating and oxidising reagents.
- Access-controlled, bunded storage. For a Group 1 carcinogen, restricting who can reach the store is part of the control, not an administrative nicety.
- Shelf life is typically 12–24 months in sealed original packing under these conditions. Re-assay before use after long storage.
Handling & PPE
- Design exposure out, do not manage it down. For a carcinogen the hierarchy of control matters: closed transfer and pump-fed charging first, ventilation second, PPE last.
- Skin protection is the priority. Toluidines are absorbed through intact skin — chemical-resistant gloves and coveralls, not just splash protection.
- Respiratory protection where vapour concentrations may build — particularly in enclosed transfer areas — per your own exposure assessment.
- Health surveillance and exposure records. Where a Group 1 carcinogen classification triggers obligations at your site, your occupational health provider and EHS function own the detail. We flag the classification; the programme is yours to run.
- Never discharge to drain or watercourse. H400 applies — collect spills and dispose of them as regulated chemical waste.
Transport
o-Toluidine moves as regulated cargo under UN 1708. We classify each consignment, apply UN-approved packaging and labelling, and file the dangerous-goods declaration before the booking is made. The applicable class and packing group are stated on your shipping documents and SDS — ask us for the current DG paperwork when you plan the shipment.
What travels with every consignment
A chemical shipment is only as good as the file that travels with it. Verifying what the source plant sends is precisely the work you are buying from a supplier.
Certificate of Analysis
Batch-specific assay by GC, water content by Karl Fischer, colour (APHA), appearance and impurity profile — checked against your purchase specification before we release the goods.
GHS Safety Data Sheet
Full 16-section SDS in GHS format covering hazards, exposure controls, handling, storage, spill response, toxicology and disposal — issued in the language your destination requires.
Dangerous Goods Declaration
UN 1708, hazard class, packing group and IMDG or IATA declaration prepared and filed before the container is booked, with correctly marked and labelled packaging.
Certificate of Origin
Chamber-attested where required, plus preferential-origin forms where a trade agreement gives your import duty relief at the destination.
Third-party inspection
SGS, Intertek or Bureau Veritas sampling and inspection arranged on request before loading, giving you independent verification of what actually ships.
Retained & pre-shipment samples
Pre-shipment samples carry the same COA as the commercial lot, so what your laboratory qualifies is exactly what arrives. Retention samples held against the batch.
The three doors out of this aniline
Almost everything made from o-toluidine leaves by one of three routes: acylation and condensation into rubber chemicals, diazotisation for colour, or chlorination and further chemistry toward herbicide actives. The routes below are the general industrial pattern, not a process disclosure.
Start with the aniline
o-Toluidine provides a primary aromatic amine with a methyl group ortho to the nitrogen, giving the specific reactivity and steric profile that rubber-chemical and herbicide routes are built around.
Door one — rubber chemicals
Condensation and further synthesis build the vulcanisation accelerators and antioxidants used across tyre and technical rubber goods manufacture.
Door two — diazotise for colour
Sodium nitrite in acid at low temperature gives the diazonium salt, coupled onto naphthol or acetoacetarylide components to build azo dyes and pigments.
Door three — herbicide chemistry
Chlorination and condensation build the chloroacetanilide herbicide actives that depend on the ortho-methylaniline starting structure.
Why feed quality carries through the whole route
Whichever door you use, anything in the feed that competes for the same chemistry, or carries its own reactive functionality, follows the material down the line:
- Isomeric toluidines react in parallel and give structurally similar products — an off-shade chromophore in colour work, an unwanted isomer in a herbicide intermediate.
- Residual water can complicate acylation, diazotisation control and chlorination chemistry alike.
- Oxidation products — the coloured species responsible for the amber drift — dull a finished shade and reduce yield in downstream condensation steps.
- Heavy residues concentrate in the still bottoms and reduce the number of passes you get from a distillation train.
That chain of consequences is the reason we quote against your written specification rather than a generic "99% technical" grade, and the reason the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Intermediate | Principal outlet |
|---|---|
| Ortho Toluidine CAS 95-53-4 — this product | Rubber chemicals Azo dyes & pigments Herbicide intermediates |
| Meta Toluidine CAS 108-44-1 | Specialty dyes Fine chemical synthesis |
| Para Toluidine CAS 106-49-0 | Azo pigments & dyes Pharma intermediates |
If your route calls for one of the others, we supply those as well — see our full product catalogue. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this intermediate
o-Toluidine is not a commodity with a screen price. Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
Rubber & agrochemical demand cycles
Tyre production and crop-protection formulation both pull on the same amine at different points of their respective seasons, so the market rarely goes quiet in the way a niche single-outlet intermediate does.
- Quote early for campaign tonnage
- Spot buying at peak costs materially more
- Contracted call-off smooths the exposure
Upstream feedstock
The route back to o-toluidine runs through toluene, nitration and reduction. Movements in toluene, ammonia and hydrogen feed through to the aniline within a quarter or so.
- Toluene price sets the floor
- Energy cost weighs on distillation
- We flag feedstock-driven moves in the quote
Regulatory pressure
The Group 1 carcinogen classification raises the compliance cost of producing, storing and moving this material significantly. That cost sits inside the price, and it is a major reason capacity has consolidated in some regions.
- Handling obligations vary sharply by jurisdiction
- Several markets restrict certain end uses
- We check destination rules before quoting
Pack format
Cost per kilo falls from drums to IBCs to ISO tanks — and with a Group 1 carcinogen, tank movement also cuts the number of times an operator opens a container.
- Drums suit trial and mid-size orders
- ISO tanks are cheapest per kilo at scale
- Less manual handling means less exposure
Freight & DG surcharges
This is regulated cargo, so ocean freight carries a hazardous surcharge and space is tighter than for general cargo. Destination and Incoterm move landed cost as much as the ex-works price does.
- Compare on landed cost, not ex-works
- DG space books out ahead of peak season
- We quote FOB, CIF, CFR or DDP as you prefer
Source availability
A plant turnaround, an environmental inspection or a regulatory tightening can take capacity offline at short notice on this line. Single-sourced buyers feel this hardest.
- We hold a second qualified source on this line
- Qualify the alternate before you need it
- Ask us about dual-source contracts
| If your end use is… | Specify |
|---|---|
| Rubber chemicals | High assay with tight isomer and moisture limits |
| Azo pigments & dyes | Colour ceiling, tight isomer limit |
| Herbicide chemistry | High assay; moisture the critical parameter for several routes |
| Pharmaceutical chain | Tight isomer limit; metals and residues reported |
| Laboratory / R&D | Small pack, high purity, full analytical pack |
Not sure which column you are in? Describe the reaction you are running and our technical desk will recommend the grade — including telling you when a cheaper specification would do the job just as well.
Support that goes beyond shipping the drum
What our technical desk will do
- Match a grade to your reaction. Tell us the step you are running and we will recommend the specification — and say so plainly when a tighter, costlier grade would add nothing.
- Be straight about the hazard profile. We state the Group 1 carcinogenicity classification at enquiry stage so your EHS team can price the controls into the decision, rather than meeting it for the first time on the label.
- Advise on handling and storage for your site conditions — closed-transfer design and ventilation planning look different in different plant layouts.
- Review your specification before it goes into a contract, so you are not locked into a limit that no plant can consistently hit.
Regulatory & compliance notes
- Carcinogen obligations are jurisdiction-specific and typically strict. Several regimes impose substitution reviews, exposure monitoring, health surveillance and record retention for Group 1 carcinogens. Confirm what applies at your site before the first delivery.
- Import controls vary by destination. Some jurisdictions apply registration, licensing, or restrict certain end uses of this material entirely. We check the destination rules before quoting, not after you have raised the PO.
- Chemical inventory listings differ between regions. Confirm your obligations under the applicable inventory regime for your import volume — we will supply the identity data you need for that filing.
- Downstream article restrictions can apply to certain rubber, colourant and consumer applications. Your regulatory team should confirm the finished-article position for the end use you have in mind.
None of the above is legal advice — your own regulatory affairs team owns the final compliance position for your import and your workplace. What we commit to is giving you accurate product identity data, an honest statement of the hazard classification and complete documentation to work from.
From enquiry to delivered drum
Send the specification
Product name or CAS 95-53-4, the assay and impurity limits you work to, quantity, pack preference and destination port.
Receive a firm quote
Pricing, lead time, packing and Incoterm confirmed in writing within 24 hours — our sourcing desk is staffed around the clock.
Qualify and approve
Sample dispatched if you are qualifying a new source. Batch COA shared for your approval before the material is released.
Ship and track
DG classification filed, freight booked, export documents issued, and the consignment tracked through transit and clearance to your plant.
Often bought alongside this grade
Consolidate several intermediates onto one shipment and one invoice. These are the anilines and aromatics our rubber, dye and agrochemical customers most often order in the same programme. Each of the following is part of our wider aniline intermediate range — browse the full product catalogue for current availability and specification sheets.
What buyers ask us about Ortho Toluidine
Is this material classified as a carcinogen?
Can I use the meta or para isomer instead?
What purity do you normally supply?
What is the minimum order quantity?
How long does delivery take?
Why does the liquid darken in storage?
How should we store it, and what is the shelf life?
Is this a dangerous good? What paperwork comes with it?
- Batch certificate of analysis
- GHS-format safety data sheet
- Dangerous-goods declaration with UN number, class and packing group
- Commercial invoice, packing list and bill of lading or airway bill
- Certificate of origin and any destination-specific forms
Do you supply to my country?
Do you manufacture this yourself?
Can you hold stock against a production plan?
Request pricing on Ortho Toluidine
Send your required assay, quantity, pack format and destination port. Our sourcing desk is available 24 hours a day, 7 days a week, and comes back with pricing, lead time and packing options — whether that is a single trial drum or a contracted tank programme for the year.