Meta Dichlorobenzene
Chlorine entering a chlorobenzene ring goes ortho and para. It does not go meta. So while the other two dichlorobenzenes fall out of a chlorinator by the tonne, this isomer has to be made on purpose — by catalytically isomerising the other two towards equilibrium and then separating out the meta compound. That is the whole story of this product: its scarcity, its price and the reason buyers specify it anyway.
Chelora Chemicals supplies m-DCB to agrochemical, pharmaceutical and dye intermediate producers worldwide, in drums, IBCs and bulk, with a full isomer profile on the batch COA and a GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 541-73-1
- IUPAC name
- 1,3-Dichlorobenzene
- Molecular formula
- C6H4Cl2
- Molecular weight
- 147.00 g/mol
- EC / EINECS
- 208-792-1
- UN Number
- 3082 · Class 9*
- SMILES
- Clc1cccc(Cl)c1
- HS Code
- 2903 99*
* The transport entry follows from the aquatic hazard rather than from flammability or acute toxicity, and the applicable entry varies with mode, quantity and destination. Confirm the HS heading with your customs broker and let us classify the consignment rather than reusing an entry from a different chlorinated aromatic.
What Meta Dichlorobenzene is used for
Meta dichlorobenzene is a colourless, clear liquid with the sweet chlorinated-aromatic odour of the family, boiling at about 173 °C and practically insoluble in water. Physically it sits between its two sister isomers and behaves much as they do. Chemically it is a different product altogether, because the two chlorines sit 1,3 to each other and that pattern is what the buyer is purchasing.
Almost all commercial demand is for the ring pattern. Nitrate it and the nitro group is directed into the position flanked by the chlorines' combined influence, giving a 2,4-dichloronitrobenzene that reduces to 2,4-dichloroaniline for dye, pigment and agrochemical chemistry. Elaborate it further and the meta arrangement appears in crop protection and pharmaceutical molecules where a 1,3-halogenated ring is part of the pharmacophore. A smaller stream goes into service as a high-boiling process solvent where the ortho isomer's properties are not quite right.
Why the isomer is the product
- Meta dichlorobenzene (CAS 541-73-1) — this product. Scarce, made by isomerisation, bought for its 1,3 substitution pattern.
- Ortho dichlorobenzene (CAS 95-50-1) — abundant, a workhorse solvent and the feed to 3,4-dichloronitrobenzene. See that page.
- Para dichlorobenzene — a crystalline solid at room temperature, which alone tells you it is a different material to handle.
- Mono chlorobenzene (CAS 108-90-7) — one chlorine only, the upstream feed to the whole family. See that page.
On this product family, quoting the CAS number on the purchase order is not a formality — see the full intermediate range.
Appearance and handling character
The material ships as a clear colourless to very pale liquid, denser than water, practically insoluble in it and miscible with most organic solvents. It is combustible rather than flammable — the flash point sits near 63 °C — and its defining regulatory feature is aquatic toxicity, which is what drives both the transport entry and your effluent obligations. The safety section below should be read before any handling is planned.
| Parameter | Typical value |
|---|---|
| Appearance | Clear colourless liquid |
| Assay (1,3-isomer) | 99.0% min |
| Ortho-dichlorobenzene | Reported per batch |
| Para-dichlorobenzene | Reported per batch |
| Mono chlorobenzene | Reported per batch |
| Trichlorobenzenes | Reported per batch |
| Moisture | 0.05% max |
| Acidity (as HCl) | 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. On this product the individual isomer figures decide whether a lot is usable — a 99% assay with the balance as ortho isomer is a different material from a 99% assay with the balance as trichlorobenzenes. Tell us your ceilings and we will quote against them.
| Property | Value |
|---|---|
| Physical state | Liquid at ambient |
| Boiling point | ≈ 173 °C |
| Freezing point | ≈ −24 °C |
| Flash point | ≈ 63 °C (closed cup) |
| Relative density | ≈ 1.29 at 20 °C |
| Vapour density | ≈ 5 (air = 1) — vapour sinks |
| Water solubility | Practically insoluble |
| Organic solubility | Miscible with alcohol, ether, most organics |
Physical constants compiled from public reference data for CAS 541-73-1 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this molecule to work
This is a pattern-carrying intermediate. Buyers are not after a chlorinated solvent — they are after two chlorines in the 1,3 arrangement, delivered into the next molecule.
Dichloroaniline chemistry
Nitration followed by catalytic reduction converts m-DCB into dichloroanilines carrying the meta chlorine relationship — diazo components and amine building blocks the ortho route simply cannot deliver.
- Nitration then reduction
- Isomer profile carries through both steps
- See our intermediate range
Agrochemical intermediates
Crop protection molecules frequently require a 1,3-halogenated ring for activity and metabolic stability. Where the route specifies that pattern, this is the economic way into it.
- End-use declaration required
- Campaign quantities available
- Technical desk review of your route
Pharmaceutical building blocks
Fine chemical and API intermediate producers use m-DCB where a meta-dihalogenated aromatic core is required. Documentation expectations are higher here, and we supply accordingly.
- Full impurity profile on request
- Consistent source lot-to-lot
- Retention samples held
Dye & pigment intermediates
The dichloroanilines derived from this isomer appear in azo chemistry, where the chlorine positions shift shade and improve fastness in ways an unsubstituted or ortho-substituted component will not reproduce.
- Shade-critical specifications supported
- Tight isomer ceilings available
- Colour-chain range on request
High-boiling process solvent
Where a reaction needs an inert, water-immiscible medium running above 150 °C and the ortho isomer is unavailable or unsuitable, m-DCB serves the same function with a slightly lower boiling point.
- Inert to most reagents
- Recoverable by distillation
- Low water carry-over
Contract & scheduled supply
This product is made on isomerisation campaigns, not continuously. Buyers who commit to a volume and take it against a schedule get both the price and the certainty; spot buyers get whatever the market has left.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Inventory released to your plan
How we supply Meta Dichlorobenzene
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. On a product made by a handful of plants worldwide and released in campaigns, that is an advantage rather than a disclaimer — we are not tied to one unit's calendar, and we are never selling you an off-spec lot because it happens to be the one in our tank.
We place your order with whichever qualified producer best matches your isomer ceilings, your price point and your delivery window.
Availability on this line is genuinely tighter than on the ortho isomer. We say so at enquiry stage, because a buyer who knows that plans a contract instead of a series of spot purchases.
- Isomer confirmed before we quote. Meta, ortho or para — three different products with three different prices and three different downstream chains.
- Every isomer reported separately. Ortho, para, mono-chloro and trichloro content appear as their own figures on the COA, not folded into one "others" line.
- Batch COA shared before dispatch. You approve the full profile against your own spec while the material is still in our warehouse.
- Honest lead times. If the next campaign is six weeks out we tell you now, not after you have raised the purchase order.
- Pre-shipment samples for qualification. New account or new source, your laboratory runs a trial before the full quantity ever moves.
- Export machinery handled in-house. Transport 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.
MS & HDPE drums
The standard commercial format. Sealed, labelled and palletised, suitable for drum pumps or direct charging, and easy to stage against a batch schedule.
IBC totes
Fewer connections and less manual handling for plants charging a tonne or more per batch, with the tote returned or disposed of per your site policy.
Bulk ISO containers
For contracted programmes, with the lowest cost per tonne and no drum disposal at your end. Lined and dedicated equipment arranged where your specification demands it.
Bulk road movement
Where the destination and volume allow, bulk road delivery direct into your storage tank, scheduled against your production calendar.
Samples & trial packs
Laboratory and pilot quantities dispatched so your R&D team can qualify the isomer profile first — subject to transport rules for your destination and courier.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with transport documentation filed before the booking is made rather than chased afterwards.
The aquatic hazard is the controlling issue
Meta dichlorobenzene is harmful if swallowed, irritating to skin, eyes and the respiratory tract, and very toxic to aquatic life with long lasting effects. On a combustible, low-water-solubility liquid, the exposure that most often causes a reportable incident is not a worker's — it is a drain's. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document.
Classified hazards
H302Harmful if swallowed.H315Causes skin irritation.H319Causes serious eye irritation.H335May cause respiratory irritation.H410Very toxic to aquatic life with long lasting effects.
Hazard statements reflect classifications commonly published for CAS 541-73-1. Chlorinated aromatics as a class are defatting to skin on repeated contact and release hydrogen chloride on combustion. Always read the SDS issued with your specific batch.
Spill & emergency orientation
Plan your response before the drums arrive. Sections 4, 5 and 6 of the SDS are the authoritative instructions and should be posted at the point of use.
- Never hose a spill to drain. H410 applies — contain with sand or inert absorbent, collect and dispose of as regulated chemical waste.
- It sinks. Denser than water, so a spill into water does not float and spread — it pools on the bottom, which makes recovery harder and the environmental case worse.
- Vapour is heavier than air. It collects in pits, sumps and trenches. Treat confined-space entry after a spill as a permit job.
- Combustible when hot. Above the flash point the vapour will ignite. Combustion releases hydrogen chloride — brief the fire team and keep run-off out of the watercourse.
- Segregate from strong oxidisers, strong bases and reactive metals in storage as well as in process.
Storage
- Cool, dry, well-ventilated store away from direct sunlight, heat sources and ignition sources. It will not freeze in an unheated winter store — the freezing point is near −24 °C.
- Keep containers tightly closed on a sealed and bunded floor sized for the largest container plus a margin. The bund is the control that matters most on an H410 material.
- Carbon steel, stainless or HDPE are normally suitable for dry material. Confirm elastomer and gasket compatibility — chlorinated aromatics swell many common seals.
- Segregate from strong oxidisers and strong bases.
- Shelf life is typically 24 months or more in sealed original packing. Re-assay before use after long storage.
Handling & PPE
- Closed transfer first. Pump or gravity-feed through fixed lines rather than decanting by hand; design the splash out before you specify the gloves.
- Chemical-resistant gloves, goggles and overalls, with contaminated clothing removed promptly — repeated skin contact defats and irritates.
- Local exhaust ventilation at drum-opening and charging points, and respiratory protection where your exposure assessment calls for it.
- Earth and bond when hot. Below the flash point static is a minor concern; above it, treat the transfer as you would a flammable.
- Never discharge to drain or watercourse. H410 applies — contain and dispose of as regulated chemical waste.
Transport
Consignments normally move as an environmentally hazardous substance, liquid, n.o.s. under UN 3082, Class 9, Packing Group III, driven by the aquatic classification rather than by flammability. The applicable entry varies with mode, quantity and destination, so we classify each consignment and file the declaration before the booking is made — ask us for the current transport 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 with ortho, para, mono-chloro and trichloro content reported individually, plus moisture and acidity — 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, ecotoxicology and disposal — issued in the language your destination requires.
Transport Declaration
UN number, class, packing group and marine pollutant status assessed per consignment, with the 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.
The isomer chlorination will not give you
Chlorine is an ortho/para director. Chlorinate chlorobenzene and you get the 1,2- and 1,4-isomers; the 1,3-compound appears only in trace. But the meta isomer is the thermodynamically most stable of the three, which is exactly what makes a catalytic isomerisation route possible. The outline below is the general industrial pattern, not a process disclosure.
Chlorinate the benzene
Chlorination of benzene and chlorobenzene gives mainly ortho and para dichlorobenzene, with the meta isomer present only at a few percent.
Isomerise over catalyst
Passing the ortho/para stream over an acidic zeolite catalyst shuffles the chlorines towards equilibrium, which favours the meta isomer and enriches it substantially.
Separate the isomers
Precision distillation and adsorptive separation split isomers that boil only a few degrees apart. This step, not the chemistry, is where the cost sits.
Carry the pattern forward
Nitration, amination or further elaboration installs the next group, with the 1,3 relationship between the chlorines preserved into the final molecule.
Why the impurity profile carries through the whole route
In isomer chemistry an impurity is not a diluent — it is a second substrate that reacts alongside yours:
- Ortho and para dichlorobenzene nitrate and aminate just as happily as the meta isomer, giving a differently substituted product that follows yours through every subsequent step and is hardest to remove at the end.
- Mono chlorobenzene gives a mono-substituted downstream product — one chlorine short, with different properties and, in a colourant, a different shade.
- Trichlorobenzenes carry an extra chlorine forward and are flagged in several jurisdictions, so they matter for regulatory as well as technical reasons.
- Moisture and acidity attack reactor metallurgy and shorten catalyst life in the downstream step, which is why both are worth a line on the specification.
That is why we quote against your written isomer ceilings rather than a generic "technical" grade, and why the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Isomer | Character & chain |
|---|---|
| Meta dichlorobenzene CAS 541-73-1 — this product | Scarce liquid, bp ≈173 °C Meta-pattern intermediates |
| Ortho dichlorobenzene CAS 95-50-1 | Abundant liquid, bp ≈180 °C Solvent, 3,4-DCNB feed |
| Para dichlorobenzene CAS 106-46-7 | Crystalline solid Entirely different handling |
| Mono chlorobenzene CAS 108-90-7 | Flammable liquid Upstream feed to the family |
We supply across the chlorinated aromatic 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.
Separation is the cost
The chemistry is cheap; splitting isomers that boil within a few degrees of each other is not. Most of what you pay above the chlorobenzene price is the distillation and adsorption duty required to isolate this isomer.
- Tighter isomer ceilings narrow the source list
- Separation energy is a real, visible cost
- We will tell you when you are over-specifying
Campaign scheduling
This isomer is produced in campaigns rather than continuously. Buy between campaigns and you are buying from someone's inventory, at inventory prices, in whatever quantity remains.
- Ask us where the campaign calendar stands
- Contracted call-off beats spot buying here
- Plan 2–4 weeks for custom material
Upstream feedstock
The route runs back through benzene, chlorination to chlorobenzene and on to the dichlorobenzenes. Benzene and chlorine economics feed through within a quarter or so, as they do across the family.
- Chlorine moves with the chlor-alkali cycle
- Benzene tracks the aromatics market
- We flag feedstock-driven moves in the quote
Co-product economics
An isomerisation unit's economics depend on placing all three isomers. When demand for the ortho or para stream softens, this isomer carries more of the plant overhead and the price firms.
- Isomer prices move together, not alone
- Ask us what the sister markets are doing
- Contracted volume smooths the exposure
Regulatory pressure
Chlorinated aromatic production carries effluent, emissions and inventory-listing obligations that have consolidated capacity into fewer, larger plants. That cost sits inside the price.
- Effluent rules shape plant economics
- Inventory listings vary by region
- We check destination rules before quoting
Freight & pack format
Drums, IBCs and ISO tanks give very different costs per tonne, and a marine pollutant entry adds documentation to every leg. Destination and Incoterm move landed cost as much as the ex-works price does.
- Compare on landed cost, not ex-works
- Bulk pays off above a few tonnes
- We quote FOB, CIF, CFR or DDP as you prefer
| If your end use is… | Specify |
|---|---|
| Nitration to dichloronitrobenzene | Tight ortho/para ceilings; low moisture and acidity |
| Agrochemical route | Full impurity profile; end-use declaration |
| Pharmaceutical intermediate | Highest available purity; consistent single source |
| Dye & pigment chain | Isomer ceilings; low trichlorobenzene content |
| Process solvent | Commercial grade; low water and acidity |
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 the dichlorobenzenes this is where orders go wrong most often, and we settle it in the first reply.
- Set the isomer ceilings with you. A single "99% min" line on a purchase order does not describe this product. The individual figures do.
- Be straight about availability. If the material is between campaigns, you will hear it at enquiry stage, when you can still plan around it.
- Review your specification before it goes into a contract, so you are not locked into a limit no plant can consistently hit.
Regulatory & compliance notes
- Chemical inventory listings differ between regions — we supply the identity data you need for that filing before the first shipment moves.
- Import controls vary by destination. We check the destination rules before quoting, not after you have raised the PO.
- Effluent and waste rules matter because of the H410 classification. Check your discharge consent against the material before introducing it.
- Workplace exposure limits for chlorinated aromatics differ by jurisdiction; your occupational hygiene team owns the monitoring position for your 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 541-73-1, your assay and individual isomer ceilings, 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
Consignment classified, freight booked, export documents issued, and the shipment tracked through transit and clearance to your plant.
Others in the Chelora range
What buyers ask us about Meta Dichlorobenzene
Why is this isomer so much more expensive?
What purity do you normally supply?
Can I use the ortho isomer instead?
Is it flammable?
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 with full isomer profile
- GHS-format safety data sheet
- Transport 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 Meta Dichlorobenzene
Send your required assay, individual isomer ceilings, 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 programme for the year.