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C8 Aromatic Isomer · CAS 108-38-3

Meta-Xylene

C6H4(CH3)2 Molar mass 106.16 g/mol

The 1,3-dimethylbenzene isomer supplied by Chelora Chemicals — the dedicated feedstock for isophthalic acid manufacture, used across PET copolymer and unsaturated-polyester-resin chemistry — exported from Indonesia in drums or ISO tanks with full batch documentation on every shipment.

Identification Sheet REP.
IUPAC name1,3-Dimethylbenzene
CAS number108-38-3
Molecular formulaC₆H₄(CH₃)₂
Molar mass106.16 g/mol
AppearanceColourless liquid, sweet aromatic odour
Common synonymsMeta-Xylene, m-Xylene, 1,3-Xylene
Melting Point−48 °Clit., lowest of the three isomers
Boiling Point139 °Cat 1 atm
Specific Gravity0.864at 20 °C
Flash Point27 °Cclosed cup
AppearanceColourless liquidsweet, aromatic odour
Purity Offered95% / 99%+ (isophthalic acid grade)technical & high-purity, liquid
01 / PRODUCT DOSSIER

What Meta-Xylene is, and why buyers source it

A working overview of the compound's chemistry, its role as the cross-substituted xylene isomer, and the grades Chelora Chemicals keeps in regular supply.

Meta-Xylene carries its two methyl groups on ring carbons separated by one position, the 1 and 3 positions. Because it is thermodynamically the most stable of the three xylene isomers, it is also the dominant isomer formed whenever a mixture is pushed toward equilibrium by acid-catalysed isomerisation, which is why isomerisation units feeding a para-xylene plant always produce more meta-xylene than the other two isomers combined.

At room temperature it is a colourless, highly flammable liquid with a sweet aromatic odour and, among the three isomers, by far the lowest freezing point, which is exactly why it is the one left behind in the mother liquor when para-xylene is recovered by fractional crystallisation. It is immiscible with water but miscible with most organic solvents.

Where it fits in the synthesis chain

Meta-Xylene's principal dedicated use is as the feedstock for isophthalic acid, produced by catalytic liquid-phase oxidation analogous to the terephthalic acid process. Isophthalic acid is used as a comonomer in PET bottle and film resins to improve clarity and crystallisation behaviour, and as a key component of unsaturated polyester and gelcoat resins prized for toughness and chemical resistance. A smaller share is used directly as a high-boiling solvent.

Grades we supply

Chelora Chemicals offers Meta-Xylene in technical grade (≈95% assay, since meta-xylene is harder to isolate in very high purity by distillation alone) for solvent and general blending use, and isophthalic-acid grade (99%+, achieved via dedicated separation) for catalytic oxidation feedstock use. Both grades are supplied with a batch-wise certificate of analysis.

02 / MANUFACTURING ROUTE

How Meta-Xylene is made

An overview of the production route for orientation purposes. Our manufacturing partners' own process parameters and in-process controls are proprietary and are not disclosed beyond what is needed to interpret the certificate of analysis.

Meta-Xylene is recovered from the mixed C8 aromatic stream, itself produced by catalytic reforming of naphtha or pyrolysis gasoline. Because its boiling point sits within about one degree of para-xylene, it cannot be separated from para-xylene by ordinary distillation; instead it is the component left behind as raffinate once para-xylene is removed by selective adsorption or fractional crystallisation, and is then further purified from residual ortho-xylene and ethylbenzene by distillation and, where very high purity is required, selective complexation or further adsorption.

Why meta-xylene is recovered as a by-stream, not a direct cut

Because para-xylene is the highest-value isomer and meta-xylene is both its closest boiling neighbour and the thermodynamically favoured isomer under isomerisation conditions, commercial xylene complexes are designed around maximising para-xylene recovery first, with meta-xylene recovered afterward from what remains — a sequencing that shapes how meta-xylene purity and cost compare with the other two isomers.

03 / APPLICATIONS

Industries and processes that use it

Meta-Xylene is consumed principally as the isophthalic acid feedstock, with a smaller share used directly as an industrial solvent. The fields below account for most of the demand we see through our export desk.

Field 01

Isophthalic Acid Feedstock

Catalytically oxidised in the liquid phase to isophthalic acid, the dominant industrial use of this isomer.

Field 02

PET Copolymer Modifier Chain

Supplies, through isophthalic acid, a comonomer used in PET bottle and film resins to improve clarity and processing behaviour.

Field 03

Unsaturated Polyester & Gelcoat Resin Chain

Supplies, through isophthalic acid, a key building block for tough, chemical-resistant unsaturated polyester and gelcoat resins.

Field 04

Industrial Solvent

Used directly as a high-boiling aromatic solvent in select coating, cleaning and specialty-formulation applications.

04 / REACTION CHEMISTRY

How the molecule is typically carried forward

The 1,3-spaced methyl groups govern almost all of this molecule's further reaction chemistry. Reaction classes below account for most of the ways Meta-Xylene is converted into a finished product or intermediate.

Catalytic Liquid-Phase Oxidation

Both methyl groups are oxidised in a bromide-promoted, cobalt/manganese-catalysed liquid-phase process to give isophthalic acid, directly analogous to the terephthalic acid process from para-xylene.

Isophthalic Acid Esterification (Polyester Chain)

Isophthalic acid is co-polymerised with terephthalic acid and ethylene glycol to modify PET resin crystallisation and clarity.

Isophthalic Acid Polycondensation (Resin Chain)

Isophthalic acid condenses with polyols and unsaturated diacids to build tough, chemical-resistant unsaturated polyester resins.

Acid-Catalysed Isomerisation (Upstream)

Meta-xylene is the thermodynamically favoured product whenever ortho- or para-xylene is isomerised over an acidic zeolite catalyst to re-equilibrate a xylene isomer mixture.

05 / RELATED BUILDING BLOCKS

Meta-Xylene against other amines we supply

Buyers sourcing Meta-Xylene for isophthalic acid or solvent use often need a related xylene isomer or the parent mixed stream. A quick reference to what else is on our regular supply list.

ProductCAS NumberCategoryNotes
Meta-Xylene108-38-3C8 aromatic isomerThe product on this page — the dedicated feedstock for isophthalic acid.
Mixed Xylenes1330-20-7C8 aromatic isomer blendThe parent stream Meta-Xylene is separated from — see its product page.
Para-Xylene106-42-3C8 aromatic isomerThe closest-boiling sibling isomer, feedstock for PET — see its product page.
Ortho-Xylene95-47-6C8 aromatic isomerThe adjacent-substituted sibling isomer, feedstock for phthalic anhydride — see its product page.

Exact physical constants and purity specifications are confirmed per batch on the certificate of analysis — treat the notes above as a sourcing guide, not a specification sheet, for products other than Meta-Xylene.

06 / HAZARD & HANDLING

Safety classification at a glance

Based on GHS classification as commonly listed for this substance. This is a summary for orientation only — always work from the current safety data sheet supplied with your specific batch.

H226

Flammable liquid and vapour.

H315

Causes skin irritation.

H319

Causes serious eye irritation.

H332

Harmful if inhaled.

PPE Standard

Chemical-resistant gloves, splash goggles and suitable respiratory protection are the baseline for routine handling.

Fire Precaution

Keep away from heat, sparks and open flame; ground and bond containers during transfer.

Inhalation Note

Use only with adequate ventilation or suitable respiratory protection to limit vapour exposure.

Signal word

Warning — GHS02 flammable and GHS07 harmful pictograms apply.

This compound is a flammable liquid that causes skin and serious eye irritation, and is harmful if inhaled. It must be handled with chemical-resistant gloves, splash-proof eye protection and suitable respiratory protection, and kept away from heat and open flame. Full first-aid, storage, spill and PPE guidance is in the MSDS issued with every shipment, and should be read in full before this material is handled.

07 / STORAGE & SHELF LIFE

Keeping it on spec between delivery and use

General storage guidance for this grade. Site-specific storage rules, segregation requirements and re-test intervals should follow your own EHS procedures and the MSDS issued with your batch.

Storage TemperatureCool, ambient, below 25 °C
ContainerSealed drums / ISO tank
Typical Shelf Life24 months, unopened
Keep Away FromHeat, open flame, strong oxidizers
Beyond Shelf LifeRe-assay before use

Store in a cool, dry, well-ventilated area away from heat sources, open flame and strong oxidizing agents, in tightly closed original packaging. Ground and bond all equipment during bulk transfer. If a batch is held past its retest date, re-check assay, isomer purity and colour before use.

08 / PACKING & EXPORT

How it ships from Indonesia

Standard packing and export terms for this product. Confirm exact figures against your order — they vary slightly by destination and quantity.

Standard Packing200 L drums (liquid)
Bulk PackingISO tank / tanker on request
Min. OrderFrom 1 tonne
Lead Time2 – 3 weeks
Export TermsFOB · CFR · CIF
09 / QUALITY & DOCUMENTATION

What travels with every batch

Specification is agreed before the purchase order, not discovered on arrival. Every shipment of Meta-Xylene leaves with a documented, checkable paper trail.

Doc 01

Certificate of Analysis

Batch-wise assay (by titration/GC), colour and relevant physical constants, issued against the agreed specification so your QC team can check it, not just file it.

Doc 02

Safety Data Sheet

GHS-format SDS in English covering hazard classification, handling, storage, first-aid and spill response for the exact grade of Meta-Xylene shipped.

Doc 03

Technical Data Sheet

Reference physical and chemical properties, recommended storage and typical applications, for internal circulation to your process or R&D teams.

Doc 04

Certificate of Origin

Confirms Indonesian origin for customs clearance and any preferential-duty claim at your destination port.

Doc 05

Dangerous Goods Declaration

UN packing group, classification and shipper's declaration prepared ahead of loading so documentation never holds up customs.

Doc 06

Third-Party Inspection

Independent pre-shipment inspection and re-sampling can be arranged on request, at your cost, for buyers who require it as a matter of policy.

10 / FAQ

Frequently asked questions

What buyers most often ask our sales desk about this grade.

01What is Meta-Xylene used for?+
Mainly as the feedstock for isophthalic acid, used as a comonomer in PET bottle and film resins and as a key component of unsaturated polyester and gelcoat resins; a smaller share is used directly as a high-boiling industrial solvent.
02What is the CAS number of Meta-Xylene?+
Its CAS Registry Number is 108-38-3, with molecular formula C₆H₄(CH₃)₂ and a molar mass of 106.16 g/mol.
03How is Meta-Xylene made?+
It is recovered as the raffinate left after para-xylene is removed from the mixed C8 aromatic stream by selective adsorption or crystallisation, then further purified from ortho-xylene and ethylbenzene by distillation.
04What purity grades does Chelora Chemicals supply?+
We supply technical grade (around 95% assay) for solvent and general blending use, and isophthalic-acid grade (99%+) for catalytic oxidation feedstock use. Each batch ships with a certificate of analysis.
05Is Meta-Xylene hazardous?+
Yes. It is a flammable liquid that causes skin and serious eye irritation, and is harmful if inhaled. It must be handled with the PPE and fire precautions specified in the MSDS supplied with each shipment.
06Why does isophthalic acid improve PET resin clarity?+
Isophthalic acid's bent, 1,3-substitution pattern disrupts the regular chain packing that drives crystallisation in pure PET, which reduces haze and improves clarity in bottle and film applications where a small percentage of isophthalic acid is copolymerised in.
07What packing options are available?+
Standard packing is 200 L drums for the liquid, with ISO tank or tanker shipment available on request for bulk quantities.
08How long does delivery take?+
Typical lead time is two to three weeks plus transit, depending on whether the grade is ex-stock or made to order and your destination port. A firm date is confirmed in the written quotation.
09Can I get a sample before placing a bulk order?+
Yes. Pre-shipment samples and a batch certificate of analysis can be arranged so your QC team can verify the specification before committing to volume.
10Do you supply other xylene isomers as well?+
Yes, we also supply Mixed Xylenes, Para-Xylene and Ortho-Xylene, the parent stream and sibling isomers in the same C8 aromatic family.
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