Mono Ethylene Glycol (MEG)
Two carbons, two hydroxyls. The co-monomer that turns terephthalic acid into polyester, and the reason a radiator does not freeze.
Molecular Structure
What is Mono Ethylene Glycol (MEG)?
Mono ethylene glycol is a two-carbon chain with a hydroxyl group on each carbon. It is clear, odourless, viscous and completely miscible with water — and it has an unmistakably sweet taste, which is the single most dangerous thing about it.
Two hydroxyls on such a short chain mean dense hydrogen bonding. That is why MEG boils at 197 °C rather than near room temperature, why it is viscous, and why it disrupts water's crystal lattice so effectively: a 50/50 mixture with water freezes near −37 °C, which is the whole basis of the antifreeze market.
Industrially it is made by hydrating ethylene oxide, either thermally with a large excess of water or catalytically for higher selectivity. Around nine tenths of it goes straight into polyester — reacted with purified terephthalic acid to make PET resin and polyester fibre.
Chelora supplies fibre-grade and industrial-grade MEG. Fibre grade is certified on UV transmittance at 220, 275 and 350 nm alongside DEG, aldehydes, acidity, iron and chloride, because those are the parameters that decide whether the polymer comes out clear.
Quick Reference
Key Physical & Chemical Properties
Structure & Bonding
A short chain with a hydroxyl at each end. That symmetry is what lets MEG act as a difunctional monomer, linking terephthalate units into a polyester chain — and the same hydrogen bonding is what makes it such an effective freezing-point depressant.
Skeletal structure — hydroxyl groups at both chain ends
Structural Identity
- IUPAC NameEthane-1,2-diol
- Common namesMEG, ethylene glycol, glycol
- Molecular FormulaC₂H₆O₂
- Molecular Weight62.07 g/mol
- Functional groupsTwo primary hydroxyls
- FunctionalityDifunctional — a diol monomer
- Made fromHydration of ethylene oxide
- SolubilityFully miscible with water
- HygroscopicYes — absorbs atmospheric moisture
- CAS Number107-21-1
- InChI KeyLYCAIKOWRPUZTN-UHFFFAOYSA-N
Product Specifications
Chelora supplies Mono Ethylene Glycol (MEG) in standard and custom grades. Contact us for specification sheets tailored to your process.
| Chemical name | Mono ethylene glycol |
|---|---|
| CAS Number | 107-21-1 |
| Molecular formula | C₂H₆O₂ |
| Molecular weight | 62.07 g/mol |
| Purity — fibre grade (min) | ≥ 99.90 wt% |
| Purity — industrial grade (min) | ≥ 99.50 wt% |
| Diethylene glycol (max) | ≤ 0.05 wt% |
| Water (max) | ≤ 0.08 wt% (Karl Fischer) |
| UV transmittance at 220 nm (min) | ≥ 75% |
| UV transmittance at 275 nm (min) | ≥ 92% |
| UV transmittance at 350 nm (min) | ≥ 99% |
| Aldehydes as acetaldehyde (max) | ≤ 10 ppm wt |
| Acidity as acetic acid (max) | ≤ 10 ppm wt |
| Iron (max) | ≤ 0.10 ppm wt |
| Chloride (max) | ≤ 0.50 ppm wt |
| Ash (max) | ≤ 5 ppm wt |
| Colour | ≤ 5 Pt-Co (Hazen) |
| Specific gravity | 1.1153 – 1.1156 at 20/20 °C |
| Distillation range | 196 – 199 °C |
| Flash point | 111 °C (closed cup) |
| Autoignition temperature | 398 °C |
| Transport classification | Not regulated as dangerous goods |
Downstream Applications & Derivatives
Key derivative chains and industrial uses of Mono Ethylene Glycol (MEG).
Polyester Fibre & PET Resin
Polycondensed with purified terephthalic acid into PET — polyester staple and filament, bottle resin, sheet and film. This single chain takes roughly nine tenths of world MEG demand.
Antifreeze & Engine Coolant
Blended with water and inhibitor packages for automotive and stationary engine cooling, giving both freeze protection to around −37 °C and a raised boiling point.
De-icing & Heat Transfer
Runway and aircraft de-icing fluids, and secondary-loop heat transfer fluids in HVAC, refrigeration and process cooling where a low-freezing water-based medium is needed.
Gas Hydrate Inhibition
Injected into subsea gas gathering lines to suppress hydrate formation, then regenerated and recycled — a distinct duty from TEG, which removes water rather than inhibiting hydrates.
Resins & Polyols
A diol building block in unsaturated polyester resins, alkyd resins and polyurethane polyols, contributing chain flexibility and reactive hydroxyl ends.
Humectant & Technical
Moisture control in adhesives, inks, textile finishing and paper, plus use as a solvent and intermediate in a range of technical formulations.
Why source Mono Ethylene Glycol (MEG) through Chelora Petrochem?
Verified Origin
Full origin certification and asset-backed supply chain documentation — no grey-market supply.
Grade Flexibility
Fibre grade and industrial grade supplied. UV transmittance, DEG, aldehyde, acidity and iron limits certified to polyester-plant requirements.
Full Documentation
CoA, SDS, UN transport docs, REACH compliance, and destination-market certificates with every shipment.
Logistics Support
Experienced in bulk aromatic liquid logistics — ISO tanks, road tankers, and drums with nitrogen blanketing where required, for Indian and international delivery.
Storage & Handling Guidelines
Always refer to the full SDS before handling. The following is a summary of key requirements.
- Store in stainless steel, aluminium or lined tanks under a nitrogen pad — glycols are hygroscopic and pick up water from humid air, which is a specification failure rather than a safety issue.
- Keep carbon steel out of the wetted path where colour and iron specifications matter; iron pickup shows up directly as colour on the certificate.
- Protect from prolonged heat and air. Extended exposure to both causes oxidation to aldehydes and organic acids, which raises acidity and destroys UV transmittance.
- Segregate grades rigorously. Fibre-grade, industrial and pharmacopoeial materials must not share hoses, pumps or lines, and dedicated equipment is the norm.
- Verify identity on receipt, not just on paper. Glycols look alike, mix freely and are commonly mis-shipped or adulterated — confirm by test before the material enters your process.
- Bund all storage and prevent any release to drains, surface water or groundwater.
- Provide eyewash and washing facilities at transfer points, and control mist or aerosol generation at spray and heated-handling points.
- Label every container clearly and never decant into unmarked or food-type containers.
Hazard Summary
Classification: Acute Tox. 4 oral (H302) · STOT RE 2 (H373, kidneys).
Ingestion is the real hazard: MEG tastes sweet and is not obviously unpleasant, which is why accidental and deliberate poisonings keep happening — children and animals are particularly at risk. It is metabolised to glycolic and then oxalic acid, causing metabolic acidosis and calcium oxalate deposition in the kidneys, and serious symptoms are typically delayed by hours.
If ingestion is suspected: Get medical attention immediately and tell the clinician ethylene glycol is involved, even if the person seems well. Effective antidotal treatment exists and works far better before symptoms develop. Do not wait for symptoms.
Container discipline: Never decant MEG into unlabelled containers or anything resembling a drinks container, and never store it where food or beverages are kept. Most domestic poisonings trace back to exactly this.
Exposure limits: ACGIH TLV 25 ppm 8-hour TWA with a 50 ppm STEL for vapour, and 10 mg/m³ for inhalable aerosol; the NIOSH ceiling is 50 ppm. There is no OSHA PEL. Confirm the limit in force in your jurisdiction.
Fire: A combustible rather than flammable liquid, with a flash point of 111 °C. It will burn if heated above that, and heated handling operations should be assessed accordingly.
PPE minimum: Safety glasses or goggles, nitrile gloves, and respiratory protection where mist or heated vapour is generated. Routine cool handling needs little more than splash protection.
Consult the full SDS for exposure limits, spill containment, emergency response, and disposal before any use.
Frequently Asked Questions
Technical and commercial questions about Mono Ethylene Glycol (MEG) sourcing and specifications.
What is MEG used for?
Around 90% goes into polyester — reacted with purified terephthalic acid to make PET resin for bottles and film, and polyester fibre, which is the largest textile fibre in the world. The best-known remaining use is engine antifreeze and coolant, alongside aircraft and runway de-icing fluids, heat transfer fluids, gas hydrate inhibition in subsea pipelines, and diol chemistry in resins and polyols.
Why does MEG work as antifreeze?
Because it dissolves completely in water and disrupts the hydrogen-bonded lattice that water needs to freeze. A roughly 50/50 mixture depresses the freezing point to about −37 °C while also raising the boiling point, so the same fluid protects against both freezing and boil-over. Commercial coolant is not neat MEG — it carries a corrosion inhibitor package matched to the engine's metallurgy.
What is fibre-grade MEG and why does UV transmittance matter?
Fibre grade is the tighter specification used by polyester producers: minimum 99.9% purity with very low DEG, aldehydes, acidity, iron and chloride. UV transmittance at 220, 275 and 350 nm is the distinctive test — it detects traces of aldehydes and other unsaturated impurities that ordinary assays miss but which show up as yellowing in the finished polymer. A UV failure means the polyester will be off-colour, so it is often the first specification a fibre plant checks.
How is MEG produced?
By hydrating ethylene oxide with water. The conventional thermal route uses a large excess of water at elevated temperature and pressure, and inevitably produces diethylene and triethylene glycol as co-products, which are separated by distillation and sold in their own right. Catalytic and omega-type processes use less water and give much higher MEG selectivity, with correspondingly less DEG and TEG.
Is MEG dangerous to handle?
The occupational hazards are modest — it is not very volatile, and skin and eye contact cause only mild irritation. The serious hazard is ingestion. MEG tastes sweet, is metabolised to acids that cause metabolic acidosis and kidney damage, and symptoms are delayed by hours so people do not realise anything is wrong. The practical controls are container discipline, clear labelling, never using food-type containers, and treating any suspected ingestion as an immediate medical emergency because antidotal treatment works best early.
What documentation does Chelora provide?
Every shipment includes a Certificate of Analysis covering purity, DEG, water, UV transmittance at 220/275/350 nm, aldehydes, acidity, iron, chloride, ash, colour, specific gravity and distillation range; a Safety Data Sheet (GHS/REACH); confirmation that the material is not regulated as dangerous goods for transport; an origin certificate; and any destination-market certificates required.
Request a quote or specification sheet
Talk to Chelora's sourcing team about Mono Ethylene Glycol (MEG) grade, volume, logistics, documentation, and lead times. We respond within one business day.
