4-Aminophenol
4-Aminophenol is one acetylation away from paracetamol. That single step is why this molecule is made in enormous quantity, and why its colour, assay and residual nitrophenol content are watched more closely than almost any other intermediate of its size.
Chelora Chemicals supplies 4-aminophenol to pharmaceutical, dye and fine-chemical producers worldwide, in UN-approved packing, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 123-30-8
- IUPAC name
- 4-Aminophenol
- Molecular formula
- C₆H₇NO
- Molecular weight
- 109.13 g/mol
- EC / EINECS
- 204-616-2
- UN Number
- 2811 · Class 6.1*
- SMILES
- Nc1ccc(O)cc1
- HS Code
- 2922 29*
* Confirm the exact UN entry, packing group and HS heading with your freight forwarder and customs broker — amino-phenols are classified against the destination's own schedule and the shipping description can differ by mode and country.
What 4-Aminophenol is used for
4-Aminophenol is a white to pale buff crystalline powder carrying an amino group and a hydroxyl group at opposite ends of a benzene ring. Both are electron-donating, which makes the ring very electron-rich — excellent for the chemistry it is used in, and the reason the material oxidises and darkens so readily in air.
Its dominant use by a very large margin is as the precursor to paracetamol, produced by acetylating the amino group with acetic anhydride. Beyond that it serves as a classical photographic developer, as an intermediate in dye and hair-dye manufacture, and as a building block for rubber chemicals and corrosion inhibitors.
Where it sits among aminophenols and nitro precursors
- 4-Aminophenol (this product) the para isomer; the only one of commercial significance for paracetamol.
- Para-nitrophenol the oxidised precursor on one of the common routes to this product. See that page.
- 2-Aminophenol the ortho isomer; a separate dye and benzoxazole intermediate, not interchangeable.
- Para-aminobenzoic acid a different amino aromatic entirely, reached via para nitrobenzoic acid.
On a pharmaceutical intermediate, confirm the CAS number and the impurity specification on your purchase order — see the full intermediate range.
Appearance and handling character
The material is sparingly soluble in cold water, soluble in hot water, ethanol and dilute acid or alkali, and it darkens steadily on exposure to air and light, moving from white through pink to grey-brown. It is classified as a suspected mutagen and a skin sensitiser, and it is very toxic to aquatic life. Dust control, light exclusion and air exclusion are the three practical requirements on this product.
| Parameter | Typical value |
|---|---|
| Appearance | White to pale buff crystalline powder |
| Assay (HPLC / titration) | 99.0% min |
| Melting range | 186 – 189 °C |
| 4-Nitrophenol | 0.1% max |
| Moisture (KF) | 0.5% max |
| Sulphated ash | 0.1% max |
| Iron | 20 ppm max |
| Colour of solution | 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. Assay, colour and residual nitrophenol are the figures that carry into the finished active — tell us your target and we will quote against it.
| Property | Value |
|---|---|
| Physical state | Crystalline solid at ambient |
| Melting point | 187 – 190 °C (with decomposition) |
| Water solubility | Sparingly soluble cold; soluble hot |
| Solvent solubility | Soluble in ethanol, dilute acid and alkali |
| Stability | Oxidises and darkens in air and light |
| Incompatibilities | Oxidising agents, strong acids, metals |
Physical constants compiled from public reference data for CAS 123-30-8 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this intermediate to work
One very large application and several steady smaller ones — but the paracetamol chain is what sets the market.
Paracetamol manufacture
Acetylation of the amino group with acetic anhydride gives paracetamol directly — the single largest consumer of this material worldwide.
- API route; end-use declaration required
- Colour and nitrophenol critical
- Full impurity profile on request
Photographic developer
The classical single-agent developer chemistry, still specified in fine-grain and concentrate formulations.
- Low-iron specification preferred
- Colour-critical grades available
- Small packs available
Dye & hair-dye intermediates
Used as a coupler and intermediate in oxidative hair colourant systems and in azo dye synthesis.
- Cosmetic end use is tightly regulated
- Destination rules checked before quoting
- See our dye intermediate range
Rubber & polymer chemicals
A building block for antioxidants and antiozonants, where the electron-rich ring is exactly the point.
- Technical-grade specification
- Bulk quantities available
- Technical desk review of your route
Research & process development
Small-scale use in route scouting and analytical reference work, with the same documentation as the commercial lot.
- Packs from 500 g
- Full analytical documentation available
- Retained sample held against the lot
Contract & scheduled supply
Paracetamol plants consume this continuously. We hold inventory and release it against your production calendar.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply 4-Aminophenol
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. On an intermediate where colour and trace impurities carry straight into a finished medicine, owning no plant means we are never defending a batch — we route your order to the producer whose impurity profile actually matches what your filing can carry.
We place your order with whichever qualified producer best matches your assay, your impurity specification, your price point and your delivery window.
We keep a second qualified source on this line. The paracetamol chain is concentrated in a small number of regions and occasionally disrupted, so a qualified alternate is worth holding.
- Colour and assay confirmed before we quote. On this product colour is a quality indicator, not a cosmetic one, and we state it on the COA rather than leaving it to inference.
- Residual 4-nitrophenol reported. It is the characteristic residue of the reduction route and the figure your QC will look at first.
- We ask what it feeds before we quote. A regulated starting material for paracetamol and a photographic grade need quite different documentation.
- Packing specified for air and light exclusion. This is a specification point on an oxidation-sensitive material, not packaging detail.
- Mutagenicity classification stated up front. Said at enquiry stage so your EHS team can plan containment before the first drum arrives.
- Export machinery handled in-house. Classification, approved packing, labelling, freight booking and customs paperwork are ours to manage.
Packed the way your plant receives it
On an air- and light-sensitive powder the pack is doing chemistry as well as containment. Tell us how the material will be charged and we will quote the format that protects it.
Lined fibre / HDPE drums
UN-approved drums with a sealed inner liner — the standard commercial format and the easiest to charge from without opening the whole drum.
Nitrogen-blanketed packing
Available where oxidation in transit is a concern, particularly on long sea legs into hot destinations.
Lined steel drums
Heavier-duty drums where the extra barrier and mechanical protection matter more than per-kilo packing cost.
Trial / sample quantities
Small, DG-compliant containers dispatched so your R&D team can qualify the grade before committing to larger volumes.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with DG documentation filed before the booking is made.
Campaign despatch
We hold contracted tonnage and release it against your production calendar — worth doing on a material with a limited shelf life.
Dust and skin contact are the controlling routes
4-Aminophenol carries a suspected mutagenicity classification, a skin-sensitisation statement and acute oral toxicity, and it is very toxic to aquatic life. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document.
Classified hazards
H341Suspected of causing genetic defects.H302Harmful if swallowed.H317May cause an allergic skin reaction.H315Causes skin irritation.H319Causes serious eye irritation.H410Very toxic to aquatic life with long lasting effects.
Hazard statements reflect classifications commonly published for CAS 123-30-8. Aminophenols are absorbed through skin as well as inhaled, and sensitised workers can react to very small later exposures. 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.
- Never dry-sweep a spill. Sweeping re-suspends the dust and turns a contained spill into an inhalation exposure — collect with a HEPA vacuum or damp methods.
- Contain, do not hose to drain. H410 applies — collect the material and dispose of it as regulated chemical waste.
- Treat contaminated clothing as waste. Remove it immediately, bag it and handle it as contaminated waste rather than sending it to an ordinary laundry.
- Wash skin thoroughly and log the exposure. Skin contact with a sensitiser and suspected mutagen is reportable at most sites.
- Expect staining. Oxidised aminophenol marks skin, clothing and surfaces, and the stain is a useful indicator of where contamination has spread.
Storage
- Cool, dry, dark, access-controlled store. Light and air both drive the oxidation that discolours the powder and lowers assay.
- Keep containers tightly closed. On an oxidation-sensitive material a part-used drum left open will be visibly worse within days.
- Segregate from oxidising agents and strong acids. Aminophenols react readily with oxidisers; keep them apart by distance, not just by label.
- Avoid contact with iron and copper. Trace metals catalyse the oxidation, which is why iron content appears on the specification.
- Shelf life typically 12–24 months. Shorter than most intermediates on this range. Re-assay and check colour before use after extended storage.
Handling & PPE
- Design dust and skin contact out. Closed transfer, contained charging and local exhaust ventilation first; PPE last, never as the sole control.
- Chemical-resistant gloves, coveralls and eye protection. With contaminated clothing removed, bagged and handled as contaminated waste.
- Respiratory protection for dust. Particulate respirators during any operation that can generate airborne powder, per your exposure assessment.
- Health surveillance for routine handlers. Given the mutagenicity classification, your occupational health provider should define a monitoring programme.
- Never discharge to drain or watercourse. H410 applies — contain and dispose of as regulated chemical waste.
Transport
4-Aminophenol generally moves as regulated cargo, most commonly under UN 2811, Class 6.1. We classify each consignment, 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, melting range, residual 4-nitrophenol, moisture, ash, iron and colour — checked against your 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, in the language your destination requires.
Dangerous Goods Declaration
UN number, hazard class and IMDG or RID/ADR declaration prepared and filed before the container is booked, with correctly marked packaging.
Analytical method & chromatogram
HPLC method and batch chromatogram on request, so your QC can reproduce the impurity profile rather than take it on trust.
Certificate of Origin
Chamber-attested where required, plus preferential-origin forms where a trade agreement gives your import duty relief.
Retained & pre-shipment samples
Pre-shipment samples carry the same COA as the commercial lot, so what your laboratory qualifies is exactly what arrives.
An amine and a phenol, para to each other
Two electron-donating groups on the same ring make this molecule reactive in exactly the way its users want — and exactly the way that makes it hard to keep white. The routes below are the general industrial pattern, not a process disclosure.
Start from a nitro aromatic
The two common industrial routes begin from nitrobenzene or from para-nitrophenol, depending on the plant.
Reduce under controlled conditions
Catalytic hydrogenation converts the nitro group to the amine, with acidic conditions on the nitrobenzene route giving the para-substituted product.
Isolate and recrystallise
The product is neutralised, filtered and recrystallised to lift assay, tighten the melting range and remove colour.
Acetylate in use
Downstream, acetic anhydride acetylates the amino group selectively, leaving the phenol untouched, to give paracetamol.
Why colour and residual nitrophenol carry through
On this intermediate, two batches at the same nominal assay can give very different finished product:
- Colour carries into the active. Oxidised aminophenol produces coloured by-products that survive acetylation and show up in your paracetamol as an off-white tint.
- Residual 4-nitrophenol is the route marker. It is unreduced starting material, it is limited in pharmacopoeial paracetamol, and it does not disappear in the acetylation step.
- Trace metals accelerate degradation. Iron and copper catalyse the oxidation, which is why they are specified despite being present at ppm levels.
- Moisture shortens shelf life. Wet material darkens faster, so the moisture figure is a stability specification as much as a stoichiometric one.
That is why we quote against your written colour and impurity limits rather than a generic "technical grade", and why the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Material | Position in the route |
|---|---|
| 4-Aminophenol CAS 123-30-8 — this product | Direct paracetamol precursor |
| Para nitrophenol CAS 100-02-7 | Upstream on one route |
| Paracetamol CAS 103-90-2 | The downstream active |
| 2-Aminophenol CAS 95-55-6 | Ortho isomer · separate routes |
We supply across this intermediate 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 product
Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
Nitrobenzene and hydrogen
Both routes depend on nitro-aromatic feedstock and on hydrogen, so benzene and energy markets feed through together.
- Benzene tracks the aromatics cycle
- Hydrogen follows natural gas
- We flag feedstock-driven moves in the quote
Paracetamol demand
This is a single-application market in practice. Analgesic demand, including seasonal and pandemic spikes, moves it directly.
- Demand spikes can be very sharp
- Contracted call-off smooths the exposure
- We hold a second qualified source
Colour and impurity specification
A photographic grade and a tightly specified pharmaceutical grade are different products from the same plant at different prices.
- Tell us the real limits, not a wish list
- We will say when a wider spec will do
- Over-specification is the commonest cost leak
Freight and DG surcharges
Class 6.1 cargo carries a hazardous surcharge, and inert-blanketed packing adds cost on top.
- 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 concentration
Production is concentrated in a small number of regions, so a single plant turnaround or environmental action moves the whole market.
- We hold a second qualified source on this line
- Qualify the alternate before you need it
- Ask us about dual-source contracts
Shelf life and inventory risk
A 12 to 24 month shelf life means stockpiling against a price move carries a real degradation cost.
- Buy to schedule rather than to price
- We hold inventory and release on call-off
- Ask about scheduled despatch
| If your end use is… | Specify |
|---|---|
| Paracetamol / regulated starting material | Tight colour and nitrophenol limits, full profile |
| Photographic developer | Low iron, colour-critical |
| Dye or hair-dye intermediate | Standard commercial grade; check cosmetic rules |
| Rubber chemical intermediate | Technical grade |
| Laboratory / reference use | Small DG-compliant pack, full COA |
Not sure which row 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 colour and impurity limits before anything else. On this intermediate both carry into the finished active, and we settle them in the first reply.
- Ask whether it is a regulated starting material. If this is filed as an RSM for paracetamol, the documentation package and change-control expectations are different.
- Recommend packing for your climate and transit. Inert blanketing is worth the cost on some routes and unnecessary on others, and we will say which.
- Be straight about the mutagenicity classification. Stated at enquiry stage so your EHS team can plan containment before the first delivery.
Regulatory & compliance notes
- Cosmetic end use is tightly regulated. Use in hair colourants is restricted and concentration-limited in several jurisdictions; confirm your position before you order.
- Import controls vary by destination. We check 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. H410 applies — check your discharge consent against the material before introducing it to site.
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 123-30-8, your assay, colour and nitrophenol 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
Classification filed, DG freight booked, export documents issued, and the consignment tracked through transit and clearance.
What buyers ask us about 4-Aminophenol
What is 4-aminophenol used for?
Why does the powder go pink or brown in the drum?
What purity do you normally supply?
Can you supply it as a paracetamol regulated starting material?
Is it hazardous?
What is the minimum order quantity?
How should we store it?
Is this a dangerous good? What paperwork comes with it?
Do you manufacture this yourself?
Request pricing on 4-Aminophenol
Send your required assay, colour and impurity limits, 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.