1,2,4-Trichloro Benzene
1,2,4-Trichloro Benzene — 1,2,4-TCB, the unsymmetrical trichlorobenzene isomer — is a high-boiling chlorinated aromatic solvent used as a dielectric and heat-transfer fluid, a dye carrier in textile processing, a high-temperature GPC solvent for polyolefin analysis, and a chemical intermediate for further chlorinated aromatic synthesis.
Chelora Chemicals supplies 1,2,4-TCB to electrical equipment manufacturers, textile dye houses, polymer testing laboratories and specialty chemical formulators worldwide, in drums, IBCs and bulk quantities, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 120-82-1
- IUPAC name
- 1,2,4-Trichlorobenzene
- Molecular formula
- C6H3Cl3
- Molecular weight
- 181.45 g/mol
- EC / EINECS
- 204-428-0
- MDL number
- MFCD00000547
- SMILES
- Clc1ccc(Cl)c(Cl)c1
- HS Code
- 2903 99*
* Confirm the exact HS heading with your customs broker — classification of chlorinated benzene derivatives varies between destination tariffs.
What 1,2,4-Trichloro Benzene is used for
1,2,4-Trichloro Benzene is a benzene ring carrying three chlorine atoms in the unsymmetrical 1,2,4-pattern. That asymmetry, combined with a high boiling point, strong dielectric properties and excellent thermal stability, is what makes the isomer the workhorse of the three trichlorobenzenes: it is the one industry actually specifies by name, far more often than the symmetrical 1,2,3- or 1,3,5-isomers.
In practice 1,2,4-TCB is bought as a functional fluid or solvent far more often than as a reactive intermediate. It is bought to insulate and cool electrical equipment, to carry disperse dyes into polyester fibre, to dissolve polyolefins for molecular-weight testing at high temperature, and to degrease and preserve.
Why the isomer matters
The three trichlorobenzene isomers are separate molecules with separate performance profiles, and the difference shows up directly in your process:
- 1,2,4-Trichlorobenzene (CAS 120-82-1) — this product. The unsymmetrical isomer, liquid at room temperature and the dominant commercial grade for dielectric, solvent and carrier applications.
- 1,2,3-Trichlorobenzene — a higher-melting, less widely used isomer with different solubility behaviour.
- 1,3,5-Trichlorobenzene — the symmetrical isomer, a solid at room temperature and comparatively rare in commercial supply.
If your purchase order simply says "trichlorobenzene", quote us the CAS number and we will confirm the correct isomer before the order is placed. We supply the related chlorobenzene range as well — see 1,2-dichlorobenzene and 1,4-dichlorobenzene.
Appearance and handling character
1,2,4-TCB ships as a colourless to pale yellow, stable liquid with an odour similar to ortho-dichlorobenzene. Its melting point of about 17 °C sits close to ordinary room temperature, so a container held in a cool store or during a cold winter transit can partially crystallise, while a warm climate keeps it comfortably liquid. It is essentially insoluble in water but miscible with most organic solvents, oils and greases. Read the safety section before planning any handling: this material is very toxic to aquatic life with long-lasting effects, and that should shape your storage and spill controls from the outset.
| Parameter | Typical value |
|---|---|
| Appearance | Colourless to pale yellow liquid |
| Assay (GC) | 99.0% min |
| Moisture (KF) | 0.05% max |
| Colour (APHA) | 20 max |
| Isomeric impurities (1,2,3- / 1,3,5-) | 1.0% max |
| Residue on evaporation | 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 spectrophotometric-grade colour specification or a controlled moisture figure, send us the specification and we will quote against it rather than against a generic grade.
| Property | Value |
|---|---|
| Physical state | Liquid at ambient temperature |
| Melting point | ≈ 17 °C |
| Boiling point | ≈ 213 – 214 °C @ 760 mmHg |
| Flash point | ≈ 110 – 113 °C |
| Auto-ignition temperature | ≈ 571 °C |
| Relative density | ≈ 1.45 (20 °C) |
| Partition coeff. (log P) | ≈ 4.28 |
| Water solubility | ≈ 0.05 g/L, essentially insoluble |
| Organic solubility | Miscible with ether, benzene, carbon disulfide and most oils |
| Odour | Aromatic, similar to o-dichlorobenzene |
Physical constants compiled from public reference data for CAS 120-82-1 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
1,2,4-TCB earns its place across electrical, textile, analytical and chemical-intermediate applications on the strength of its high boiling point, dielectric stability and solvency for otherwise hard-to-dissolve materials.
Dielectric & heat-transfer fluid
Long valued in transformers and other electrical equipment for its dielectric strength and thermal stability at high operating temperatures, serving as an insulating and cooling medium in specialised electrical applications.
- High dielectric strength at elevated temperature
- Thermally stable synthetic transformer fluid
- Confirm end-use compliance for your jurisdiction
Dye carrier for textiles
Used as a carrier solvent in disperse-dye processing, helping dye molecules penetrate polyester and other synthetic fibres more evenly at dyeing-bath temperature.
- Disperse-dye carrier chemistry
- Improves dye uptake uniformity
- Trial lots available for process qualification
High-temperature GPC solvent
The reference solvent for gel permeation chromatography of polyethylene and polypropylene, where samples must be dissolved and analysed at temperatures well above 160 °C to break down crystallinity. Spectrophotometric-grade lots are stocked for this use.
- Polyolefin molecular-weight testing
- Spectrophotometric grade available
- Low-residue lots for sensitive detectors
Industrial degreasing
A powerful, high-boiling solvent for oils, greases and waxes on metal and machined parts, valued where an aqueous or lower-boiling solvent will not lift stubborn residue.
- High solvency for oils and waxes
- Suited to high-temperature cleaning lines
- Emission and disposal controls apply — ask us
Wood preservative formulations
Used historically as a component of certain wood-preservative and biocide formulations, where its solvency and stability carried active ingredients into timber. Regulatory status varies significantly by jurisdiction — confirm before specifying this use.
- Component in some legacy preservative systems
- Regulatory acceptance varies by country
- We check destination rules before quoting for this use
Chemical intermediate & specialty synthesis
A feedstock for further chlorinated-aromatic and heterocyclic synthesis, and a high-boiling reaction solvent where its thermal stability and inertness toward many reagents are the properties actually being bought.
- Further chlorination and substitution chemistry
- High-boiling inert reaction medium
- Available in trial and laboratory quantities
How we supply 1,2,4-Trichloro Benzene
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. We own no chlorination plant — and for a solvent bought as much on colour and residue specification as on assay, 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 colour specification, your price point and your delivery window.
We keep a second qualified source on this line. When a plant goes down for maintenance, or a regional supply disruption hits, your campaign switches source rather than stalling.
- Specification read against the CAS first. We confirm you need 120-82-1 and not the 1,2,3- or 1,3,5-isomer before we quote a price.
- Batch COA shared before dispatch. You approve the assay, colour and moisture profile against your own spec while the material is still in our warehouse.
- Hazard status stated up front. This material is very toxic to aquatic life with long-lasting effects, 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 process or laboratory team runs a trial batch before the full quantity ever moves.
- Packing chosen for a low-melting liquid. With a melting point close to room temperature, pack format and insulated stowage are planned with you rather than assumed.
- 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 1,2,4-TCB alongside other intermediates from our range — one invoice, one shipment, one counterparty.
Packed the way your plant receives it
Pack format drives your landed cost and your handling effort — and for a liquid that is very toxic to aquatic life, it also drives your spill and disposal exposure. Tell us how it will be charged at your end and we will quote the format that suits your operation.
Amber glass & HDPE bottles
Spectrophotometric-grade and analytical lots supplied in amber glass bottles for laboratory GPC work, where colour and residue specifications are strict.
Lined steel drums
UN-certified drums with a chemical-resistant liner, the default format for industrial, dielectric-fluid and dye-carrier quantities moving by LCL or FCL.
IBC totes
Composite IBC totes for mid-scale industrial and campaign quantities, offering easier mechanical handling and fewer container movements per tonne than drums.
ISO tank containers
For full-container and contracted annual tonnage, giving the lowest per-litre cost and the least handling exposure for high-volume industrial buyers.
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
Electrical-equipment and textile-processing plants often run to a maintenance or production calendar. We hold contracted tonnage and release it against your plan rather than landing it all at once.
Handle this as an aquatic hazard, harmful liquid
1,2,4-Trichloro Benzene is harmful if swallowed, causes skin irritation, and is very toxic to aquatic life with long-lasting effects — it is that last point that should shape your storage and spill planning above everything else. 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
H302Harmful if swallowed.H315Causes skin irritation.H410Very toxic to aquatic life with long lasting effects.
Hazard statements reflect the harmonised GHS classification commonly published for CAS 120-82-1. Supplier classifications may differ in detail; always read the SDS issued with your specific batch.
Spill & emergency orientation
Plan your response before the drum arrives, not after it 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, never hose to drain. The H410 classification means any release toward a drain, watercourse or storm system is a serious environmental incident — bund and absorb, do not wash away.
- Use an inert absorbent. Absorb spilled liquid onto sand, vermiculite or a proprietary absorbent and collect into a labelled, sealed container for disposal as chemical waste.
- Assume skin contact risk. Chemical-resistant gloves and coveralls should be worn for any transfer, sampling or spill-response operation.
- Have the SDS with the casualty. If ingestion or significant skin contact occurs, the treating clinician needs the product identity and CAS number in hand.
- Record and report environmental releases. Given the aquatic toxicity classification, most jurisdictions expect any release to soil or water to be reported through your environmental permitting framework.
Storage
- Cool, dry, well-ventilated store, away from direct sunlight and heat sources. With a melting point of about 17 °C, an unheated store in a cold climate can partially solidify a drum — plan indoor or insulated storage where winters are severe.
- Keep containers tightly closed. Evaporative loss and moisture pick-up are both worth controlling in a solvent bought partly on colour and residue specification.
- Segregate from strong oxidising agents, with which this chlorinated aromatic is incompatible.
- Bunded storage over an impervious floor, given the aquatic-toxicity classification — a bund is your first line of defence against an environmental release.
- Shelf life is typically 24 months or more in sealed original packing under these conditions; this is a chemically stable liquid, but re-assay before use in a colour- or residue-sensitive application after long storage.
Handling & PPE
- Closed transfer where practical, particularly for dielectric-fluid and GPC-solvent use, where operator exposure and product purity both benefit from a closed line.
- Skin and eye protection — chemical-resistant gloves and splash goggles for sampling, charging or drum-opening operations.
- Ventilate the work area where the liquid is heated or handled at volume, given its aromatic odour and vapour pressure.
- Never discharge to drain, soil or watercourse. H410 applies — collect any spillage or waste as regulated chemical waste and dispose of it through a licensed route.
- Keep away from strong oxidisers and open flame during storage and transfer, notwithstanding the comparatively high flash point.
Transport
1,2,4-TCB moves as regulated cargo in most jurisdictions. We classify each consignment, apply UN-approved packaging and labelling, and file the dangerous-goods declaration before the booking is made. The applicable UN number, 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, moisture by Karl Fischer, colour (APHA), isomeric purity and residue — 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, ecotoxicology and disposal — issued in the language your destination requires.
Dangerous Goods Declaration
UN number, 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.
Why an unsymmetrical trichlorobenzene
Most of what makes 1,2,4-TCB valuable is not a reaction it undergoes but a property it has: a very high boiling point and strong solvency in a molecule that is otherwise chemically quiet. The route below is the general industrial picture, not a process disclosure.
Start from benzene or chlorobenzene
Sequential electrophilic chlorination of benzene, or further chlorination of di- or monochlorobenzene, builds up the trichlorinated ring under Lewis-acid catalysis.
Isomer separation
Chlorination gives a mixture of trichlorobenzene isomers; fractional distillation isolates the 1,2,4-isomer, which predominates and is the commercially significant grade.
Purify to grade
Distillation and drying bring the material to the colour, moisture and residue specification each end use demands — tight for GPC solvent, looser for a dielectric or degreasing fluid.
Onward chemistry
Where the chlorine substituents themselves are the reactive handle, 1,2,4-TCB is a feedstock for further chlorinated-aromatic and heterocyclic synthesis.
Why colour and residue carry as much weight as assay
Because so much of the demand for 1,2,4-TCB is as a solvent or fluid rather than a reagent, the specification that matters most is often not the assay percentage but what else is present:
- Isomeric trichlorobenzenes shift the melting behaviour of the blend and can cloud a cold-store drum even at nominal assay.
- Colour bodies matter directly in GPC and dielectric-fluid use, where a spectrophotometric detector or an insulation test is sensitive to trace chromophores.
- Residue on evaporation is the parameter a GPC laboratory checks most closely — it shows up directly as detector baseline drift.
- Moisture content matters for dielectric performance, where even trace water measurably degrades insulating properties.
That 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 |
|---|---|
| 1,2,4-Trichlorobenzene CAS 120-82-1 — this product | Dielectric & heat-transfer fluid Dye carrier High-temp GPC solvent |
| 1,2,3-Trichlorobenzene | Niche solvent and intermediate use |
| 1,3,5-Trichlorobenzene | Specialty synthesis, solid at ambient temperature |
If your process calls for a different chlorobenzene grade, we supply those as well — see our full chlorobenzene derivative range. Send the CAS number and we will confirm the correct material before quoting.
What actually moves the price of this intermediate
1,2,4-TCB 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.
Cross-industry demand
Electrical, textile and analytical demand pull on the same production capacity at different times, and regulatory pressure in some regions has consolidated capacity rather than expanded it.
- Quote early for campaign tonnage
- Spot buying at peak costs materially more
- Contracted call-off smooths the exposure
Upstream feedstock
The route back to 1,2,4-TCB runs through benzene and chlorine. Movements in benzene and chlor-alkali pricing feed through to the finished solvent within a quarter or so.
- Chlorine and benzene set the floor
- Energy cost weighs on distillation and isomer separation
- We flag feedstock-driven moves in the quote
Regulatory attention
The aquatic-toxicity classification and its persistence in the environment mean some jurisdictions apply extra reporting, use restrictions or watch-list status to this molecule — that compliance cost sits inside the price.
- Water-framework and discharge rules vary by region
- Some end uses face restriction in specific markets
- We check destination rules before quoting
Grade and colour specification
Spectrophotometric-grade material for GPC use costs meaningfully more than a technical or dielectric-fluid grade, because the tighter colour and residue limits remove yield at the final purification step.
- Colour ceiling is often the cost driver
- We check whether the tighter spec is actually needed
- Technical grade is adequate for most solvent uses
Freight & DG surcharges
This is regulated cargo in most trade lanes, 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 review or a regional supply 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 |
|---|---|
| Dielectric / transformer fluid | Low moisture, controlled colour, high assay |
| Dye carrier | Standard commercial assay, colour as agreed |
| GPC / polyolefin analysis | Spectrophotometric grade, low residue on evaporation |
| Degreasing / industrial solvent | Technical grade adequate for most uses |
| Laboratory / R&D | Small pack, high purity, full analytical pack |
Not sure which row you are in? Describe the application 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 application. Tell us whether you need dielectric-fluid, dye-carrier or GPC-solvent performance 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 aquatic-toxicity classification at enquiry stage so your EHS team can price the bunding and disposal controls into the decision, rather than meeting it for the first time on the label.
- Advise on handling and storage for your site conditions — a cool store near the 17 °C melting point behaves differently in a temperate climate than in the tropics.
- 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
- Environmental discharge rules vary by jurisdiction. The aquatic-toxicity classification means some regions apply specific water-discharge or reporting obligations to sites handling this material. Confirm what applies at your site before the first delivery.
- Import controls vary by destination. Some jurisdictions apply registration, licensing or end-use restrictions to this material, particularly for preservative or biocide uses. 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.
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 pallet
Send the specification
Product name or CAS 120-82-1, the assay and colour 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 chlorobenzenes and solvents our electrical, textile and analytical customers most often order in the same programme. Browse the full range on our products page — individual specification sheets are available on request.
What buyers ask us about 1,2,4-Trichloro Benzene
Is this material classified as a carcinogen?
Can I use the 1,2,3- or 1,3,5-isomer instead?
What purity do you normally supply?
What is the minimum order quantity?
How long does delivery take?
The drum arrived partly crystallised. Is it off-spec?
Is 1,2,4-TCB compatible with polyethylene and polypropylene equipment?
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 1,2,4-Trichloro Benzene
Send your required assay, colour specification, 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 ISO-tank programme for the year.