Diethylene Glycol (DEG)
Two MEG units joined by an ether bridge. A useful diol and solvent — and the glycol with the worst safety record in the industry, for reasons that have nothing to do with its intended use.
Molecular Structure
What is Diethylene Glycol (DEG)?
Diethylene glycol is two ethylene glycol units linked through an ether oxygen — a longer chain with the same pair of terminal hydroxyls. Inserting that ether linkage raises the boiling point to 246 °C, increases viscosity, and lowers the hydroxyl density per unit mass.
Those changes are exactly why DEG is useful rather than redundant. In an unsaturated polyester or a polyurethane polyol, the longer, more flexible segment between hydroxyls gives a softer, tougher, less brittle resin than MEG would. The ether oxygen also improves solvency for dyes, resins and nitrocellulose.
Almost all DEG arises as a co-product of MEG manufacture, formed when ethylene oxide reacts with MEG that is already present rather than with water. Plant operators control the ratio through water excess and catalyst choice, so DEG supply is tied to MEG production rather than being made to order.
Chelora supplies industrial-grade DEG at ≥99.0 wt% with water, MEG, TEG and acidity certified. Because DEG has repeatedly been mis-supplied into pharmaceutical and food chains in place of glycerine or MPG, we identify every consignment by test and label it unambiguously.
Quick Reference
Key Physical & Chemical Properties
Structure & Bonding
One ether oxygen inserted between two ethylene glycol units. That single change lengthens the chain, softens any polymer it goes into, and improves solvency — the whole reason DEG is a product in its own right rather than an impurity.
Skeletal structure — two glycol units joined by an ether oxygen
Structural Identity
- IUPAC Name2,2'-Oxydi(ethan-1-ol)
- Common namesDEG, diglycol, dihydroxydiethyl ether
- Molecular FormulaC₄H₁₀O₃
- Molecular Weight106.12 g/mol
- StructureTwo glycol units + one ether oxygen
- FunctionalityDifunctional — terminal hydroxyls
- OriginCo-product of MEG manufacture
- SolubilityFully miscible with water
- HygroscopicYes — more so than MEG
- CAS Number111-46-6
- InChI KeyMTHSVFCYNBDYFN-UHFFFAOYSA-N
Product Specifications
Chelora supplies Diethylene Glycol (DEG) in standard and custom grades. Contact us for specification sheets tailored to your process.
| Chemical name | Diethylene glycol |
|---|---|
| CAS Number | 111-46-6 |
| Molecular formula | C₄H₁₀O₃ |
| Molecular weight | 106.12 g/mol |
| Purity (min) | ≥ 99.00 wt% |
| Mono ethylene glycol (max) | ≤ 0.50 wt% |
| Triethylene glycol (max) | ≤ 0.50 wt% |
| Water (max) | ≤ 0.10 wt% (Karl Fischer) |
| Acidity as acetic acid (max) | ≤ 0.005 wt% |
| Ash (max) | ≤ 50 ppm wt |
| Iron (max) | ≤ 0.20 ppm wt |
| Chloride (max) | ≤ 1.0 ppm wt |
| Colour | ≤ 10 Pt-Co (Hazen) |
| Specific gravity | 1.1180 – 1.1200 at 20/20 °C |
| Distillation range | 244 – 249 °C |
| Flash point | 124 °C (closed cup) |
| Autoignition temperature | 229 °C |
| Transport classification | Not regulated as dangerous goods |
Downstream Applications & Derivatives
Key derivative chains and industrial uses of Diethylene Glycol (DEG).
Unsaturated Polyester Resins
A softening diol in UPR formulations, giving tougher, less brittle laminates than MEG alone. Used across FRP, gelcoats, marine and construction composites.
Polyurethane Polyols
A chain extender and initiator in polyester and polyether polyols, contributing flexible ether segments to rigid and semi-rigid polyurethane systems.
Morpholine & Derivatives
Amination with ammonia gives morpholine, used as a boiler-water corrosion inhibitor, rubber accelerator intermediate and specialty solvent.
Solvent & Coalescent
Dissolves dyes, nitrocellulose, resins and printing inks, and acts as a coalescing aid in waterborne systems where a high-boiling, water-miscible solvent is needed.
Plasticisers & Esters
Esterified with benzoic and fatty acids into plasticisers for adhesives, sealants and PVC systems, and used in triethylene-type ester chemistry.
Humectant & Technical
Moisture conditioning in textiles, paper, cork and adhesives, plus use in brake fluid formulations and as a gas dehydration medium in some installations.
Why source Diethylene Glycol (DEG) through Chelora Petrochem?
Verified Origin
Full origin certification and asset-backed supply chain documentation — no grey-market supply.
Grade Flexibility
Industrial grade supplied with MEG, TEG, water, acidity and colour certified. Positive identity testing on every consignment as standard.
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.
- Never supply, store or blend DEG anywhere in a food, pharmaceutical or oral-care chain — it is not a substitute for glycerine, sorbitol or propylene glycol under any circumstances.
Hazard Summary
Classification: Acute Tox. 4 oral (H302) · STOT RE 2 (H373, kidneys).
Substitution is the historic killer: DEG has caused repeated mass-poisoning incidents worldwide — beginning with the 1937 Elixir Sulfanilamide disaster and recurring in cough syrups and oral medicines in multiple countries as recently as the 2020s. In every case DEG was substituted for, or contaminated, glycerine or propylene glycol destined for oral products.
What that means in practice: Anyone buying glycerine, sorbitol or MPG for a pharmaceutical, food or oral-care application must test incoming material for DEG identity and content rather than relying on a supplier certificate. Correspondingly, DEG must never enter those supply chains, and dedicated storage and labelling are essential.
Toxicology: Like MEG, DEG is metabolised to acidic products causing metabolic acidosis and acute kidney injury, with neurological effects in severe cases. Onset is delayed. Treat any suspected ingestion as an immediate medical emergency and tell the clinician DEG is involved.
Exposure limits: No widely established occupational exposure limit exists for DEG. Control vapour and mist to the same standard as MEG, and manage the ingestion risk through labelling and segregation rather than airborne monitoring.
Fire: A combustible liquid with a flash point of 124 °C. Note the autoignition temperature of 229 °C is comparatively low, so hot surfaces matter more than ignition sources in heated handling.
PPE minimum: Safety glasses or goggles, nitrile gloves, and respiratory protection where mist or heated vapour is generated.
Consult the full SDS for exposure limits, spill containment, emergency response, and disposal before any use.
Frequently Asked Questions
Technical and commercial questions about Diethylene Glycol (DEG) sourcing and specifications.
What is DEG used for?
Unsaturated polyester resins and polyurethane polyols take the largest share, where DEG's longer, more flexible chain softens the finished resin relative to MEG. It is also converted to morpholine, used as a high-boiling water-miscible solvent for dyes, inks and nitrocellulose, esterified into plasticisers, and used as a humectant in textiles, paper and adhesives.
Where does DEG come from?
Almost all of it is a co-product of MEG manufacture. When ethylene oxide is hydrated, some of it reacts with MEG that has already formed rather than with water, giving DEG and then TEG. Plants control the ratio through water excess and catalyst selection, but they cannot eliminate it — which means DEG supply is tied to MEG production rather than being produced independently to meet demand.
Why does DEG have such a serious safety reputation?
Not because of its intended uses, which are ordinary industrial applications, but because it has repeatedly been substituted for glycerine or propylene glycol in oral medicines. The 1937 Elixir Sulfanilamide deaths in the United States led directly to modern drug safety regulation, and comparable incidents have recurred in several countries since, including cough syrup poisonings in the 2020s. The chemical is only dangerous in this context because it looks, mixes and pours like the harmless glycols it gets confused with.
How do buyers protect against DEG contamination?
By testing identity on receipt rather than trusting paperwork. Anyone sourcing glycerine, sorbitol or MPG for pharmaceutical, food or oral-care use should run a specific test for DEG on every incoming lot — pharmacopoeial monographs require this, and the recurring incidents have almost all involved certificates that were either falsified or copied forward. On the supply side it means dedicated storage, unambiguous labelling and never blending DEG into anything that could reach an oral product.
What is the difference between MEG, DEG and TEG?
They are a homologous series. MEG is one two-carbon unit with a hydroxyl at each end; DEG adds an ether oxygen and a second unit; TEG adds a third. Each addition raises the boiling point and viscosity, increases hygroscopicity and reduces the hydroxyl density. That is why MEG dominates polyester, DEG suits softer resins and solvency, and TEG — the most hygroscopic — is the standard medium for drying natural gas.
What documentation does Chelora provide?
Every shipment includes a Certificate of Analysis covering purity, MEG and TEG content, water, acidity, ash, iron, chloride, colour, specific gravity and distillation range; positive identity confirmation; 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 Diethylene Glycol (DEG) grade, volume, logistics, documentation, and lead times. We respond within one business day.
