Para Nitrotoluene
The one nitrotoluene that is a solid. That is not a trivia point — it is why para can be crystallised cleanly out of a nitration mixture while its siblings are still being distilled, and it is why this isomer anchors two separate chains: p-toluidine for dyes and pigments, and PNTOSA for the stilbene optical brighteners that make paper, detergent and textile look white.
Chelora Chemicals supplies PNT to brightener producers, dye and pigment houses and fine chemical plants worldwide, in UN-approved packing, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 99-99-0
- IUPAC name
- 1-Methyl-4-nitrobenzene
- Molecular formula
- C7H7NO2
- Molecular weight
- 137.14 g/mol
- EC / EINECS
- 202-808-0
- UN Number
- 3446 · Class 6.1
- SMILES
- Cc1ccc(cc1)[N+](=O)[O-]
- HS Code
- 2904 20*
* Confirm the exact HS heading with your customs broker. Note also that molten material ships under a different UN entry (1664) from flaked or bagged solid.
What Para Nitrotoluene is used for
Para nitrotoluene is a yellow crystalline solid melting around 52 °C. It accounts for roughly a third of the output of toluene nitration, and because it is the only solid of the three it separates from the mixture by crystallisation rather than by distillation alone.
Two chains dominate its demand. Reduction gives p-toluidine, a diazo and coupling component used across azo dye and pigment manufacture. Sulphonation gives PNTOSA — para nitrotoluene ortho sulphonic acid — which is oxidatively coupled to DNS acid, reduced to DAS and built into the triazinyl stilbene optical brightening agents used in paper, detergent and textile. Smaller streams run to p-nitrobenzoic acid, p-nitrobenzaldehyde and various agrochemical and pharmaceutical intermediates.
Why the isomer decides the market
- Para nitrotoluene (CAS 99-99-0) — this product. A solid; leads to p-toluidine and to the brightener chain.
- Ortho nitrotoluene (CAS 88-72-2) — the majority isomer, a liquid; reduces to o-toluidine. See that page.
- Meta nitrotoluene (CAS 99-08-1) — only a few per cent of the nitration; scarce and priced well above the other two. See that page.
- PNTOSA (CAS 121-03-9) — the sulphonated derivative, and the product most PNT buyers are actually heading toward. See that page.
On this product family the CAS number is not a formality. Always state it on the purchase order — see the full intermediate range.
Appearance and handling character
The material ships as a yellow crystalline solid or flake, practically insoluble in water and soluble in hot alcohol, ether and benzene. Like all nitrotoluenes it is absorbed through intact skin and is a methaemoglobin former, so dermal exposure rather than inhalation is usually the controlling route in a risk assessment. The safety section below should be read before any handling is planned.
| Parameter | Typical value |
|---|---|
| Appearance | Yellow crystalline solid / flake |
| Assay | 99.0% min |
| Setting point | 51.0 °C min |
| Ortho isomer | Reported per batch |
| Meta isomer | Reported per batch |
| Dinitrotoluene content | Reported per batch |
| Moisture | 0.2% max |
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. For brightener producers the setting point and the ortho figure between them are the practical acceptance test — tell us your ceilings and we will quote against them rather than against a generic grade.
| Property | Value |
|---|---|
| Physical state | Crystalline solid at ambient |
| Melting point | ≈ 51 – 54 °C |
| Boiling point | ≈ 238 °C @ 760 mmHg |
| Flash point | ≈ 106 °C |
| Relative density | ≈ 1.10 (solid) |
| Water solubility | Practically insoluble |
| Organic solubility | Soluble in hot alcohol, ether, benzene |
| Sulphonation behaviour | Sulphonates ortho to the methyl group |
Physical constants compiled from public reference data for CAS 99-99-0 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
Two chains carry most of the volume — one reduces the nitro group, the other sulphonates the ring first and reduces much later.
Optical brightener chain
Sulphonation gives PNTOSA, oxidative coupling gives DNS acid, reduction gives DAS, and condensation with cyanuric chloride gives the stilbene brighteners used in paper, detergent and textile whitening.
- Largest single demand stream
- See PNTOSA
- Tight isomer limits usually apply
p-Toluidine production
Catalytic reduction gives p-toluidine with the methyl group untouched — a diazo and coupling component for azo dyes and pigments and a building block for several fine chemical routes.
- Catalytic hydrogenation route
- Isomer content carries through
- See our intermediate range
Dye & pigment chemistry
Para-substituted toluidines diazotise and couple into azo dyes and organic pigments, where the methyl group para to the amine shifts the shade and improves fastness on fibre.
- Diazo and coupling component routes
- Shade sensitive to isomer content
- Colour-critical specification on request
Oxidation products
Oxidising the methyl group gives p-nitrobenzoic acid and p-nitrobenzaldehyde, both used in pharmaceutical and fine chemical synthesis where the nitro group is reduced at a later stage.
- Methyl oxidation routes
- High-purity grade available
- Technical desk review of your route
Agrochemical & pharma intermediates
Para-substituted toluene derivatives appear in several agrochemical and pharmaceutical synthesis routes where the 1,4 relationship between the two groups is structurally required.
- End-use declaration required
- Full impurity profile on request
- Custom synthesis quantities available
Contract & scheduled supply
Brightener plants run to campaign and Class 6.1 freight needs planning. Most 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 Para Nitrotoluene
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. Brightener chemistry is unforgiving about what comes in the bag, so owning no plant means we can route your order to the producer whose crystallisation actually delivers the setting point your process needs.
We place your order with whichever qualified producer best matches your assay, your isomer limit, your price point and your delivery window.
We keep a second qualified source on this line. When a plant goes down for maintenance, your campaign switches source rather than stalling.
- Isomer confirmed before we quote. Para, ortho or meta — same formula, three different downstream chains, and a long history of wrong pallets arriving.
- Setting point reported on every COA. It is the quickest honest read on this material, and the number your incoming QC can check in an hour.
- Brightener-grade limits understood. We know why your ortho ceiling is tighter than a dye buyer's, and we quote against yours rather than theirs.
- Batch COA shared before dispatch. You approve assay, setting point and isomer profile against your own spec while the material is still in our warehouse.
- Skin absorption stated up front. Nitrotoluenes pass through intact skin — we say so at enquiry stage so your EHS team can plan the right controls.
- Export machinery handled in-house. UN 3446 classification, approved packing, labelling, freight booking and customs paperwork are ours to manage.
Packed the way your plant receives it
Pack format drives your landed cost and your handling effort. Tell us how the material will be charged at your end and we will quote the format that suits your operation.
UN bags / fibre drums
Lined, UN-approved 25 kg packs for Class 6.1 solids — the standard commercial format and the easiest for manual charging.
HDPE drums
Sealed drums with inner liner for longer storage, humid destinations or warehouses that run warm enough to risk caking near the melting point.
Low-dust & molten options
Flaked product reduces airborne fines during charging. Where you charge molten and have heated receipt facilities, molten movement can be arranged — note it ships under UN 1664, not 3446.
Samples & trial packs
Laboratory and pilot quantities dispatched so your R&D team can qualify the grade first — subject to DG rules for your destination and courier.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with DG documentation filed before the booking is made rather than chased afterwards.
Campaign despatch
Dangerous-goods space needs planning. We hold contracted tonnage and release it against your production calendar instead of landing it all at once.
Skin absorption is the controlling route
Para nitrotoluene is toxic by the oral, dermal and inhalation routes, harmful to aquatic life, and a methaemoglobin former. On a low-volatility solid, the exposure that actually hurts people is usually dermal rather than inhaled — which should shape your controls. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document.
Classified hazards
H301Toxic if swallowed.H311Toxic in contact with skin.H331Toxic if inhaled.H315Causes skin irritation.H319Causes serious eye irritation.H373May cause damage to organs through prolonged or repeated exposure.H411Toxic to aquatic life with long lasting effects.
Hazard statements reflect classifications commonly published for CAS 99-99-0. Nitrotoluenes as a class are methaemoglobin formers and are associated with effects on blood and liver on repeated exposure. Always read the SDS issued with your specific batch.
Spill & emergency orientation
Plan your response before the pallet arrives. 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. H411 applies — collect spilled solid mechanically, avoid raising dust and dispose of it as regulated chemical waste.
- Assume skin absorption. Contaminated clothing is a continuing exposure route — remove it immediately and wash the skin thoroughly with soap and water.
- Expect delayed presentation. Methaemoglobinaemia may appear some hours after exposure. A casualty who feels fine should still be assessed, with the SDS in hand.
- Sulphonation is strongly exothermic. Adding a nitroaromatic solid to oleum releases substantial heat — charge rate control, calorimetry and properly sized relief belong in the process design.
- Segregate from reducing agents, alkalis and strong oxidisers in storage as well as in process.
Storage
- Cool, dry, well-ventilated and access-controlled store, away from direct sunlight and heat sources. Note the melting point near 52 °C — in a hot warehouse bagged product will cake.
- Keep containers tightly closed on a sealed and bunded floor. Dust and fines from a damaged pack are the most likely route to an unplanned exposure.
- Segregate from reducing agents, alkalis and strong oxidisers.
- Restrict access. With a toxic-by-skin-contact classification, controlling who enters the store is a genuine control measure.
- Shelf life is typically 24 months or more in sealed original packing. Re-assay before use after long storage.
Handling & PPE
- Design skin contact out. Closed transfer, contained charging and dust suppression first; ventilation second; PPE last.
- Chemical-resistant gloves and coveralls, with contaminated clothing removed, bagged and handled as contaminated waste rather than sent to an ordinary laundry.
- Respiratory protection during pack opening, charging and any operation that can generate airborne fines, per your own exposure assessment.
- Health surveillance. Where repeated-exposure organ toxicity triggers obligations at your site, your occupational health provider owns the detail.
- Never discharge to drain or watercourse. H411 applies — contain and dispose of as regulated chemical waste.
Transport
Solid nitrotoluenes move as regulated cargo under UN 3446, Class 6.1; molten material moves as a liquid under UN 1664. We classify each consignment accordingly, apply UN-approved packaging and labelling, and file the dangerous-goods declaration before the booking is made — 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, setting point, ortho and meta isomer content, dinitrotoluene content and moisture — checked against your purchase specification before release.
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 3446 for solid or UN 1664 for molten, with hazard class, packing group and IMDG or IATA declaration prepared and filed before the container is booked.
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.
Two chains from one molecule
Reduce the nitro group and you are in dye chemistry. Sulphonate the ring first and you are in brightener chemistry. The routes below are the general industrial pattern, not a process disclosure.
Nitrate toluene
Mixed acid — sulphuric with nitric, strength trimmed with oleum — gives the ortho, para and meta mixture.
Crystallise out the para
Para is the only solid of the three, so it separates by crystallisation. The setting point on your COA is a direct measure of how well that worked.
Sulphonate or reduce
Oleum sulphonation ortho to the methyl group gives PNTOSA; catalytic reduction instead gives p-toluidine. Two different plants, two different markets.
Couple and build
PNTOSA is oxidatively coupled to DNS acid and reduced to DAS for brighteners; p-toluidine is diazotised and coupled into dyes and pigments.
Why feed quality carries through the whole route
The brightener chain is the least forgiving user of this molecule, because the finished product is judged on whiteness — a property that any structural variant degrades:
- Ortho isomer sulphonates to a different acid, couples to an unsymmetrical stilbene and survives all the way to the finished brightener as reduced whiteness or an off-tone.
- Meta isomer does the same, and carries the additional cost of being the scarce isomer you did not intend to buy.
- Dinitrotoluenes consume oxidant, hydrogen and catalyst you budgeted for your product.
- Setting point is the quick practical read on all of the above, which is why buyers watch it as closely as the assay figure.
That is why we quote against your written isomer limit rather than a generic "technical" grade, and why the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Intermediate | Downstream chain |
|---|---|
| Para nitrotoluene CAS 99-99-0 — this product | PNTOSA, p-toluidine Brighteners, dyes |
| PNTOSA CAS 121-03-9 | DNS acid → DAS Optical brighteners |
| Ortho nitrotoluene CAS 88-72-2 | o-Toluidine Dyes, pigments, rubber |
| Meta nitrotoluene CAS 99-08-1 | m-Toluidine Dyes, agro, fine chemicals |
We supply across the nitrotoluene family — see the full intermediate range. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this intermediate
Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
Brightener demand leads
Detergent and paper brightener consumption is the biggest single pull on this isomer. When brightener plants run hard, PNT tightens regardless of what dye demand is doing.
- Watch the detergent and paper cycles
- Book ahead of your own season
- Contract pricing avoids the spike
Co-product economics
One nitration makes all three isomers at a near-fixed ratio. If ortho demand collapses, the line slows and para gets scarcer even though nobody's para demand changed.
- Isomer prices move together, not alone
- Ask us what the sister markets are doing
- Contracted call-off smooths the exposure
Upstream feedstock
Toluene, nitric acid and sulphuric acid or oleum set the floor. Toluene tracks the refinery aromatics pool, so a petrochemical move shows up here within a quarter or so.
- Toluene follows the aromatics cycle
- Oleum cost feeds the sulphonation too
- We flag feedstock-driven moves in the quote
Purity tier
Brightener-grade material with a tight ortho ceiling costs more than dye-grade, because the crystallisation has to work harder. Specify the tier you need, not the tightest one available.
- Tighter isomer limits narrow the source list
- Crystallisation energy is a real cost
- We will tell you when you are over-specifying
Freight & DG surcharges
Class 6.1 cargo 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 monsoon disruption can take capacity offline at short notice. 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 |
|---|---|
| Sulphonation to PNTOSA | Tight ortho ceiling; high setting point; low moisture |
| Reduction to p-toluidine | Isomer limit; low moisture for catalyst life |
| Dye & pigment chemistry | Isomer limit; consistent setting point |
| Oxidation to the acid/aldehyde | High assay; full impurity profile |
| Laboratory / reference | Highest available purity, small DG-compliant pack |
Not sure which column you are in? Describe what you make from it 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
- Confirm the isomer before anything else. On this product family that is the single most common source of a wasted shipment, and we settle it in the first reply.
- Match the grade to the chain. A brightener producer and a dye producer need different ortho ceilings on the same product, and we quote each against their own.
- Be straight about the hazard profile. Toxic by all three routes, skin-absorbed and aquatic-toxic — stated at enquiry stage so your EHS team can plan.
- 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
- Nitroaromatic obligations are jurisdiction-specific. Several regimes impose exposure monitoring, health surveillance and record retention for this class. Confirm what applies at your site before the first delivery.
- Import controls vary by destination. We check the destination rules before quoting, not after you have raised the PO.
- Chemical inventory listings differ between regions — we will supply the identity data you need for that filing.
- Effluent and waste rules matter because of the aquatic classification. Check your discharge consent against the material before introducing it.
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 accurate product identity data, an honest statement of the hazard classification and complete documentation to work from.
From enquiry to delivered pallet
Send the specification
Product name or CAS 99-99-0, your assay, setting point and isomer limits, 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
UN 3446 classification filed, DG freight booked, export documents issued, and the consignment tracked through transit and clearance to your plant.
What buyers ask us about Para Nitrotoluene
How is this different from the ortho and meta isomers?
What purity do you normally supply?
Why does isomer content matter so much for brighteners?
Is it absorbed through the skin?
What is the minimum order quantity?
How long does delivery take?
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?
Request pricing on Para Nitrotoluene
Send your required assay, setting point, isomer ceiling, 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 pack or a contracted programme for the year.