Para Dichlorobenzene 1,4-Dichlorobenzene · p-DCB
The crystalline chloroaromatic behind polyphenylene sulfide resin — and the classic active in moth-control and deodorant blocks. Supplied at 99.5% minimum purity, crystallised away from its ortho and meta isomers.
Chelora Chemicals delivers p-DCB to PPS producers, dye houses and consumer-product formulators across the United States, with a batch COA and SDS on every consignment.
- CAS Number
- 106-46-7
- EC Number
- 203-400-5
- IUPAC name
- 1,4-Dichlorobenzene
- Molecular formula
- C₆H₄Cl₂
- Molecular weight
- 147.00 g/mol
- Melting point
- 53.5 °C
- Boiling point
- 174 °C
- UN Number
- UN 3077
- HS Code
- 2903 91
Note: p-DCB sublimes at room temperature — keep containers closed and storage ventilated. Confirm exact transport classification for your shipment with your regulatory affairs team.
From benzene to dye intermediate
Para dichlorobenzene is one link in a chain we supply end to end. Every stage below is a product on this site — follow the chain to the grade you actually need.
Co-products at the dichlorobenzene stage: ortho and meta isomers, separated by crystallisation and distillation · further chlorination gives the trichlorobenzenes
What p-DCB is used for
Para dichlorobenzene is a white crystalline solid with a strong, penetrating odour, supplied as flakes or crystals. It is the 1,4 isomer of dichlorobenzene, formed alongside the ortho and meta isomers when benzene is chlorinated, and separated from them by crystallisation because of its much higher melting point.
Its single largest industrial use is as the chloroaromatic monomer for polyphenylene sulfide (PPS), the high-temperature engineering thermoplastic used in automotive under-bonnet parts, electrical connectors and pump components. Alongside that it remains the active in moth-control and space-deodorant blocks, and serves as a building block for chlorinated dye, pigment and agrochemical intermediates.
The isomer family
- Para (1,4) — this product. Crystalline solid, melts at 53.5 °C, the PPS and deodorant-block grade.
- Ortho (1,2). Liquid at room temperature, used as a process solvent and for further chlorination.
- Meta (1,3). The minor isomer, a specialty intermediate.
- Further chlorination gives 1,2,4-trichlorobenzene and 1,2,3-trichlorobenzene.
Handling character
Para dichlorobenzene is a combustible solid that sublimes at ambient temperature and is very toxic to aquatic life. Full hazard detail is in the Safety section below.
| Parameter | Typical value |
|---|---|
| Appearance | White crystalline flakes or crystals |
| Purity (p-DCB) | 99.5% min |
| ortho-Dichlorobenzene content | 0.5% max (tighter on PPS grade) |
| Crystallising point | 52.5 °C min |
| Moisture | 0.1% max |
| Colour (molten, APHA) | Within producer specification |
Important: the figures above are indicative of commercial material and are offered for planning only. The batch certificate of analysis is the governing document.
| Property | Value |
|---|---|
| Physical state | White crystalline solid, strong pungent odour |
| Melting point | 53.5 °C |
| Boiling point | 174 °C |
| Density (solid) | ≈ 1.25 g/cm³ |
| Water solubility | Slightly soluble (~80 mg/L at 25 °C) |
| Flash point | ≈ 65 °C closed cup (combustible solid) |
| Volatility | Sublimes slowly at room temperature |
Physical constants compiled from public reference data for CAS 106-46-7 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put p-DCB to work
From high-temperature PPS resin to deodorant blocks and chlorinated dye chemistry.
Polyphenylene sulfide (PPS)
Condensed with sodium sulfide to build PPS, the high-temperature engineering resin used in automotive, electrical and pump components.
- Tighter isomer and moisture limits
- Heated bulk or jumbo-bag supply
- Technical desk review on request
Moth control & deodorant blocks
The classic active in mothballs, urinal and toilet blocks and space deodorants, where slow sublimation does the work.
- Technical and industrial grades
- Flake and crystal forms
- Documented batch traceability
Dye & pigment intermediates
Nitrated to 2,5-dichloronitrobenzene, then reduced to the chloroanilines that feed azo dye and pigment chemistry.
Agrochemical intermediates
A chlorinated aromatic building block in herbicide and fungicide synthesis routes, upstream of the dichloroanilines.
- Feeds 2,4-dichloroaniline chemistry
- Read the agrochemical guide
Pharmaceutical & fine chemicals
Feedstock for chlorinated aromatic intermediates used in pharmaceutical and fine-chemical synthesis.
- Research & process-scale quantities
- Full documentation supplied
Contract & scheduled supply
Plants running continuous consumption are supported with scheduled bulk delivery against a call-off calendar.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
Delivered to US plants and ports
We ship para dichlorobenzene to nominated delivery points across the United States. The regions below are destinations we serve — Chelora Chemicals is a sourcing and supply partner, not a US manufacturer, and does not hold US stock.
Gulf Coast
The largest US chemical cluster, and the usual entry point for bulk and molten consignments.
- Houston & Galveston, TX
- New Orleans & Baton Rouge, LA
- Mobile, AL
Northeast
Container and bagged delivery into the mid-Atlantic and New England manufacturing belt.
- Newark & Elizabeth, NJ
- Philadelphia, PA
- Boston, MA
Southeast
Port-side delivery for the Carolinas, Georgia and Florida polymer and formulation plants.
- Savannah, GA
- Charleston, SC
- Jacksonville, FL & Norfolk, VA
Midwest & Great Lakes
Inland rail and truck forwarding from the nearest coastal port to the industrial Midwest.
- Chicago, IL
- Detroit, MI
- Cleveland & Columbus, OH
West Coast
Pacific routing for West Coast formulators and engineering-plastics compounders.
- Los Angeles & Long Beach, CA
- Oakland, CA
- Seattle & Tacoma, WA
Southwest & Mountain
Inland delivery to interior states, forwarded from the Gulf or Pacific gateway.
- Dallas–Fort Worth, TX
- Phoenix, AZ
- Denver, CO
Importing into the United States
Para dichlorobenzene is a TSCA-regulated chemical substance. Under TSCA section 13 the importer of record, or its authorised agent, must certify to US Customs and Border Protection that each shipment either complies with TSCA or is not subject to it. We confirm the substance's TSCA Inventory status and agree in writing who files that certification before the first consignment moves.
Which party carries that duty follows the Incoterm. On FOB, CFR or CIF terms it is usually the US buyer; on DDP terms it can be the seller or its agent. Safety data sheets and labels are supplied to OSHA's updated Hazard Communication Standard, and the marine-pollutant marking required for UN 3077 is applied before booking.
| Item | How it works |
|---|---|
| Delivery points | Any nominated US plant, warehouse or port of discharge |
| Incoterms quoted | FOB · CFR · CIF · DDP |
| Importer of record | Agreed in writing before the first shipment |
| TSCA certification | Section 13 positive certification filed at entry |
| Documentation | Batch COA, SDS, packing list, certificate of origin |
| Pack formats | Bags, FIBC, drums or heated bulk ISO tank |
Note: regional coverage describes where we deliver, not where we hold inventory. Lead time depends on producer scheduling and ocean transit to your nominated US port — we confirm both in the quotation.
How we supply para dichlorobenzene
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. Isomer purity, moisture and colour on melt decide whether a lot runs cleanly in PPS or dye chemistry — that shapes how we select producers on this line.
We place your order with whichever qualified producer best matches your required grade, your price point and your delivery window, and confirm US import requirements before booking.
We keep a second qualified source on this line, so a single-plant disruption never becomes your production problem.
- Isomer purity confirmed before we quote. Residual ortho isomer is checked against your limit, not just the headline assay.
- TSCA status and import certification settled first. We confirm Inventory status and agree who files the section 13 certification before the first shipment.
- UN 3077 documentation managed end to end. Classification, marine-pollutant marking and carrier compliance confirmed before booking.
- Batch traceability to the producing plant. Full chain of custody documentation on request.
- One desk for the whole chain. Order p-DCB alongside monochlorobenzene, the trichlorobenzenes and the downstream chloroanilines.
- Grade matched to your process. PPS, technical and block-moulding grades quoted against the right specification.
Bagged, drummed or shipped molten
Lined bags, jumbo bags, drums or heated bulk — tell us your preferred format and we will quote and classify to it.
25 kg & 50 kg lined bags
PP-woven or multi-wall paper bags with a polyethylene inner liner to hold back moisture and vapour.
500 kg & 1000 kg jumbo bags
Liner-fitted bulk bags for plants handling material by hoist or bag-tip station.
Fibre & HDPE drums
Sealed drums where a rigid, stackable pack suits your warehouse and handling route.
Heated ISO tank
Molten delivery in heated tanks for large continuous consumers who melt on receipt anyway.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with documentation filed before booking.
Trial / sample quantities
Small packs dispatched for process qualification before a commercial order is placed.
Sublimes at room temperature — handle accordingly
Para dichlorobenzene is a combustible solid that releases vapour at ambient temperature and is very toxic to aquatic life. The summary below is orientation only — the safety data sheet supplied with your specific batch is the authoritative document.
Classified hazards
H319Causes serious eye irritation.H351Suspected of causing cancer.H410Very toxic to aquatic life with long lasting effects.
Carcinogen listings. IARC places para dichlorobenzene in Group 2B (possibly carcinogenic to humans) and the US National Toxicology Program lists it as reasonably anticipated to be a human carcinogen. It is also listed under California Proposition 65. Confirm your site's obligations with your EHS team.
Storage
Store in closed containers in a cool, dry, well-ventilated area away from heat, ignition sources, oxidisers and foodstuffs. Because the solid sublimes, vapour accumulates in sealed or poorly ventilated stores — ventilate before entry.
Handling
Handle with local exhaust ventilation and dust control. Avoid inhaling vapour or dust, wear eye protection and gloves, and keep washings out of drains and surface water given the aquatic-toxicity classification.
Transport
Commonly shipped as UN 3077, Environmentally hazardous substance, solid, n.o.s. (1,4-dichlorobenzene), Class 9, Packing Group III, marked as a marine pollutant. We confirm and document the exact classification and routing for your specific shipment and destination.
Every batch, documented
We verify documentation before dispatch so there are no surprises at your incoming-goods bench.
Specification agreed
Purity, residual ortho isomer, crystallising point and moisture confirmed against your process requirement before order placement.
Producer batch testing
The producing plant tests each batch against the agreed specification before release.
Documentation review
COA, SDS, TSCA certification data and UN 3077 transport paperwork checked by our desk before the shipment is booked.
Traceable dispatch
Each shipment is traceable to its producing batch, with full chain-of-custody records on request.
How p-DCB is made
Para dichlorobenzene is produced by the catalytic chlorination of benzene over a Lewis-acid catalyst such as ferric chloride. The reaction gives monochlorobenzene first, then a mixed dichlorobenzene stream in which the para and ortho isomers dominate, with a little meta.
Because the para isomer melts at about 53.5 °C while the ortho isomer stays liquid well below room temperature, the two are separated by fractional crystallisation — the para isomer is frozen out of the mixture and the mother liquor is distilled to recover the ortho. That melting-point gap is the whole basis of the separation, and it is why both isomers reach the market together.
Downstream, nitration with mixed acid from nitric acid and sulfuric acid gives 2,5-dichloronitrobenzene, which is reduced to 2,5-dichloroaniline for azo dye chemistry.
We do not publish operating process parameters here; this is background only. Full technical documentation accompanies every shipment, and any process-specific detail you need is best confirmed directly with our technical desk.
| Chemical family | Chlorinated aromatic hydrocarbon |
|---|---|
| Functional groups | Two chlorine substituents, para (1,4) orientation |
| Reactivity | Nucleophilic aromatic substitution with sulfide; nitration; amination |
| Upstream | Benzene, monochlorobenzene |
| Co-products | Ortho and meta dichlorobenzene |
| Downstream | PPS resin, 2,5-dichloronitrobenzene, chlorinated anilines |
The rest of the chloroaromatic range
Isomers, upstream feedstocks and the downstream intermediates p-DCB leads to — all supplied from the same desk.
Para dichlorobenzene, answered
What is para dichlorobenzene used for?
What is the difference between para, ortho and meta dichlorobenzene?
Is para dichlorobenzene hazardous?
What grade and purity do you supply?
What packing do you offer?
Do you supply para dichlorobenzene in the United States?
Who is the importer of record for US shipments?
What is para dichlorobenzene converted into downstream?
What documentation comes with each shipment?
Do you manufacture this yourself?
Get a quote on para dichlorobenzene
Send us your required grade, pack size, US delivery point and Incoterm. We will come back with a firm quote, lead time and full documentation — and can price the upstream and downstream grades in the same enquiry.