Polyethylene Glycol
PEG is one polymer sold as a ladder of physical forms. The chemistry does not change from 400 to 6000 — only the chain length does, and with it the material goes from a clear pourable liquid to a hard, waxy solid. Formulators exploit that by blending grades rather than choosing one.
Chelora Chemicals supplies polyethylene glycol to pharmaceutical, nutraceutical, cosmetic and industrial manufacturers worldwide, across the liquid and solid grades, with a batch COA, GHS safety data sheet and the glycol-impurity data your QA file needs.
Product identity
- CAS Number
- 25322-68-3
- Compendial name
- Polyethylene Glycol / Macrogol
- Repeat unit
- —(CH₂CH₂O)ₙ—
- Grades supplied
- 400 · 1500 · 4000 · 6000 · 8000
- Food additive number
- E1521
- Pharmacopoeias
- USP-NF · Ph. Eur. · JP · IP · BP
- Transport status
- Non-hazardous
- HS Code
- 3907 20*
* Confirm the exact HS heading with your customs broker — polyether polyols can sit under a different subheading depending on the destination tariff schedule and the declared end use.
What Polyethylene Glycol is used for
Polyethylene glycol is a linear polymer of ethylene oxide, terminated at each end by a hydroxyl group. Low molecular weight grades are clear, colourless, slightly viscous liquids; above roughly 1000 the material becomes a waxy solid, and by 6000 it is a hard flake or powder. All of it is water-soluble, which is unusual for a polymer and is most of why it is so widely used.
In pharmaceutical manufacture it works as a suppository and ointment base, a plasticiser in aqueous film coating, a solvent and co-solvent in liquid dosage forms, a carrier for solid dispersions of poorly soluble drugs, and a lubricant and binder in tableting. Higher grades are also used as osmotic laxatives in their own right, and the polymer appears throughout cosmetics and industrial formulation.
Where the grades differ
- PEG 400 clear viscous liquid; solvent, co-solvent, plasticiser, and the liquid half of a suppository blend.
- PEG 1500 soft, paste-like; used to bridge between liquid and solid grades.
- PEG 4000 waxy solid flake; suppository and ointment bases, solid dispersions, tablet lubricant.
- PEG 6000 harder solid; higher-melting bases, hot-melt extrusion, and where a firmer set is wanted.
Most formulations use two grades together — see the full excipient range.
Appearance and handling character
The material is hygroscopic, water-soluble and stable, with no odour in pharmaceutical grades. It is not classified as a hazardous substance. The practical questions are moisture pick-up, slow peroxide formation on exposure to air and heat, and the residual-impurity profile — ethylene oxide, 1,4-dioxane, ethylene glycol and diethylene glycol — which is where the real QA attention belongs on this product.
| Parameter | Typical value |
|---|---|
| Appearance | Clear liquid (400) to white waxy solid (4000/6000) |
| Average molecular weight | Within ±10% of nominal |
| Hydroxyl value | Per grade |
| pH (5% solution) | 4.5 – 7.5 |
| Water content | 1.0% max |
| Ethylene glycol + diethylene glycol | 0.25% max (total) |
| Ethylene oxide | 1 ppm max |
| 1,4-Dioxane | 10 ppm max |
| Residue on ignition | 0.1% max |
Important: the figures above are indicative of compendial-grade material and are offered for planning only. The batch certificate of analysis is the governing document. Glycol and residual-solvent limits differ between USP-NF and Ph. Eur. editions — tell us which you cite and we will quote against it.
| Grade | Form & typical role |
|---|---|
| PEG 400 | Liquid · solvent, plasticiser |
| PEG 600 | Liquid · low-melting blends |
| PEG 1500 | Soft solid · blend bridge |
| PEG 4000 | Waxy flake · suppository base |
| PEG 6000 | Hard flake/powder · firm bases, HME |
| PEG 8000 | Hard solid · tablet and coating work |
Numbering conventions differ slightly between regions — European macrogol numbering and some US grade names are not always aligned. Send us the grade you currently buy and we will cross-reference it.
Where our customers put this excipient to work
Few excipients cover as much ground — a liquid solvent and a hard wax from the same polymer family.
Suppository & pessary bases
Blends of a liquid and a solid grade give a water-soluble base whose melting range can be tuned to the climate and the active.
- PEG 400 + PEG 4000/6000 blends
- Melting range tuned per market
- Technical desk review of your blend
Film-coating plasticiser
PEG 400 and 6000 are the standard plasticisers in aqueous HPMC coating systems, preventing brittle films and edge chipping.
- Pairs with HPMC E grades
- Typically 1–3% of coating solids
- Coating trials supported
Solid dispersions & solubility
Solid grades act as hydrophilic carriers for poorly soluble actives in melt and solvent dispersion routes, including hot-melt extrusion.
- PEG 4000 and 6000 grades
- Low-peroxide specification advisable
- Pairs with PVP K30
Ointments & topical bases
Water-soluble ointment bases that wash off cleanly, widely used where a greasy petrolatum base is unwanted.
- PEG ointment USP-type bases
- Preservative compatibility to check
- Cosmetic grade available
Tablet lubricant & binder
Solid grades serve as a water-soluble lubricant where magnesium stearate's hydrophobicity would hurt dissolution.
- Alternative to magnesium stearate
- Granulation binder in melt routes
- Blend trials supported
Cosmetic & industrial use
Humectant and viscosity modifier in personal care, and a lubricant, mould release and heat-transfer fluid in industry.
- Cosmetic and technical grades
- Different specification from pharma
- Bulk and contract supply
How we supply Polyethylene Glycol
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. On a glycol-family excipient with a well-documented contamination history, owning no plant means we are never defending a captive unit's quality record — we route your order to the producer whose glycol impurity data actually stands up.
We place your order with whichever qualified producer best matches your grade, your compendial requirement, your price point and your delivery window.
We keep a second qualified source on this line. Ethylene oxide supply is concentrated and occasionally disrupted, so a qualified alternate is worth holding.
- Ethylene glycol and diethylene glycol tested every batch. Not skip-lot, not inherited from the producer's certificate — this is the one test on this product we will not take on trust.
- Residual ethylene oxide and dioxane reported. Both follow from the polymerisation route, and both belong on the COA rather than in a general statement.
- Grade cross-referenced before we quote. Macrogol and PEG numbering do not align perfectly across regions; send what you buy and we will identify the true equivalent.
- Peroxide value available on request. If the material carries an oxidation-sensitive active, the monograph alone will not tell you what you need.
- Full regulatory statement pack. BSE/TSE, GMO, allergen, residual solvent, elemental impurity and nitrosamine risk statements with the consignment.
- Change notification taken seriously. If a source plant changes anything that touches your filing, you hear about it from us first.
Packed the way your plant receives it
Liquid and solid grades ship quite differently, so the pack conversation starts with which grade you are buying. Tell us how it will be charged and we will quote accordingly.
HDPE / lined steel drums
The standard format for PEG 400 and other liquid grades, with a liner suited to long sea transit.
Lined bags & fibre drums
Flake and powder grades in PE-lined multiwall bags or lined fibre drums on shrink-wrapped pallets.
IBC & jumbo bags
IBCs for liquid grades and lined FIBCs for solids, where your receiving infrastructure supports bulk handling.
Trial / sample quantities
Small sealed packs of each grade so your formulation team can run base and coating trials before committing.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with export documentation filed before the booking is made.
Campaign despatch
We hold contracted tonnage by grade and release it against your production calendar rather than landing it all at once.
The impurity profile is the whole story
PEG itself is not classified as hazardous and has an extremely long record of safe use. The attention on this product belongs almost entirely on what else might be in the drum — residual monomer, dioxane, and above all the glycols. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document.
Hazard position
GHSNot classified as a hazardous substance or mixture.GLYCOLEthylene and diethylene glycol are limited impurities, not components — verify per batch.PEROXCan form peroxides slowly on exposure to air, light and heat.SLIPSpilled liquid grades are extremely slippery underfoot.
Diethylene glycol contamination of glycol-type excipients has caused mass-casualty incidents more than once, in several countries, within living memory. That is why the glycol test on this product is treated as mandatory per batch rather than periodic. Always read the SDS issued with your specific batch.
Practical handling notes
- Verify glycols on your own authority. Identity testing the polymer is not enough; the limit test is what protects the patient, and it belongs in your incoming procedure.
- Keep drums sealed and cool. Air, light and heat are what drive peroxide formation; a part-used drum left open is the usual cause.
- Melt solid grades gently. Overheating accelerates degradation and raises peroxide and aldehyde content.
- Check preservative compatibility. PEG can reduce the effectiveness of parabens, which matters in any preserved topical or liquid product.
- Clean liquid spills promptly. PEG 400 on a hard floor is a serious slip hazard and spreads further than you expect.
Storage
- Cool, dry, tightly closed, protected from light. Ordinary warehouse conditions, but air exclusion matters more here than on most excipients.
- Keep liquid grades above their cloud point. PEG 400 thickens markedly in a cold store and becomes difficult to pump or pour.
- Keep solid grades away from heat. Flakes soften and cake well below their melting range in a hot warehouse.
- Segregate from strong oxidising agents. Standard practice for a polyether.
- Shelf life typically 24–36 months. In sealed original packing. Re-test peroxide value before use after extended storage.
Handling & PPE
- Standard GMP handling. Gloves and safety glasses; no special respiratory protection is needed for the polymer itself.
- Use closed transfer for liquid grades. Pumping rather than decanting keeps air out of the drum as well as off the floor.
- Control melt temperature. Jacketed vessels with temperature control rather than direct heat when melting solid grades.
- Dedicated equipment per grade. Cross-contamination between molecular weights changes your melting profile.
- Dispose of as ordinary non-hazardous waste. Subject to your local waste classification.
Transport
Polyethylene glycol is not a regulated dangerous good and ships as general cargo by road, sea and air. We issue the commercial and compendial documentation with every consignment — ask us for the full document pack when you plan the shipment.
What travels with every consignment
On a glycol-family excipient, verifying the certificate is not a formality. It is the single most important thing a supplier does on this product.
Certificate of Analysis
Batch-specific average molecular weight, hydroxyl value, pH, water content, residue on ignition and the full glycol and residual-solvent panel.
Glycol limit test & chromatogram
Ethylene glycol and diethylene glycol results with the method and batch chromatogram, so your QC can reproduce the figure rather than accept it.
GHS Safety Data Sheet
Full 16-section SDS in GHS format, issued in the language your destination requires, confirming the unclassified status in writing.
Residual ethylene oxide & dioxane
Both reported per batch — the characteristic residues of the polymerisation route, and the ones your filing will reference.
BSE/TSE, GMO, halal & kosher
Fully synthetic with no animal-derived material at any stage; certification and allergen statements supplied with the consignment.
Retained & pre-shipment samples
Pre-shipment samples carry the same COA as the commercial lot, so what your laboratory qualifies is exactly what arrives.
One repeat unit, a whole ladder of products
Chain length is the only variable that distinguishes PEG 400 from PEG 6000, and it governs everything downstream. The steps below are the general industrial pattern, not a process disclosure.
Start from ethylene oxide
Ethylene oxide, produced from ethylene, is the single monomer feedstock for the whole PEG range.
Polymerise onto an initiator
Base-catalysed ring-opening polymerisation onto water or a glycol builds the chain, with the stopping point setting the grade.
Neutralise and purify
Catalyst is neutralised and removed, and stripping brings residual monomer and dioxane down to compendial limits.
Finish to liquid or flake
Liquid grades are filtered and drummed; solid grades are flaked or prilled to the physical form you receive.
Why molecular weight and residuals both matter
Two drums can both meet the monograph and give quite different results:
- Average molecular weight is a distribution, not a number. Two lots at the same average can have different spreads, and the spread is what sets your melting behaviour in a suppository base.
- Hydroxyl value is the practical MW check. It is faster and more reproducible than a direct measurement, which is why the monographs lean on it.
- Peroxide content rises in storage. Slowly, but enough to matter where the PEG is carrying an oxidation-sensitive active in a solid dispersion.
- Glycol content is a patient-safety limit, not a performance one. It will not change how your product behaves — which is exactly why it has to be tested rather than inferred from performance.
That is why we test glycols every batch and will get you peroxide data on request, and why the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Material | Character / use |
|---|---|
| Polyethylene glycol CAS 25322-68-3 — this product | Water-soluble · liquid to solid |
| Propylene glycol CAS 57-55-6 | Liquid co-solvent and humectant |
| Poloxamer EO/PO block copolymer | Surfactant and gelling agent |
| Glycerin CAS 56-81-5 | Humectant · same glycol test discipline |
We supply across the excipient range — see the full excipient range. Send your formulation and we will confirm the grades before quoting.
What actually moves the price of this product
Knowing what drives the quote helps you time a purchase and read whether an offer is realistic.
Ethylene oxide economics
The whole range comes from one monomer, so ethylene and EO pricing feed through to every grade simultaneously.
- Ethylene tracks the petrochemical cycle
- EO capacity is concentrated and regulated
- We flag feedstock-driven moves in the quote
Pharma versus technical grade
Technical PEG and compendial PEG come off the same reactors with very different purification and testing burdens.
- Never cross-shop grades on price alone
- Pharma grade carries the glycol panel
- We will say when technical grade will do
Liquid versus solid freight
Drummed liquid and palletised flake load very differently, and the choice of grade changes your freight per kilo materially.
- Compare on landed cost, not ex-works
- IBC vs drum changes the number
- We quote FOB, CIF, CFR or DDP as you prefer
Grade campaign scheduling
Plants run molecular weight campaigns, so lead time on a specific grade depends on where the cycle sits rather than on availability generally.
- Ask us where the campaign calendar sits
- Contracted call-off smooths the exposure
- We hold inventory on 400 and 6000
Source qualification lead time
On a glycol-family excipient the qualification burden is heavier than most, which makes a supply gap genuinely expensive.
- We hold a second qualified source on this line
- Qualify the alternate before you need it
- Ask us about dual-source contracts
Cosmetic & industrial demand
Personal care and industrial applications consume very large PEG volumes and compete for the same reactors.
- Ask us what adjacent demand is doing
- Long-term contracts lock in supply
- Pharma grades are partly insulated
| If your application is… | Specify |
|---|---|
| Suppository base | PEG 400 + PEG 4000 or 6000 blend |
| Film-coating plasticiser | PEG 400 or PEG 6000 |
| Solid dispersion / hot-melt | PEG 4000 or 6000, low peroxide |
| Liquid co-solvent | PEG 400 |
| Water-soluble tablet lubricant | PEG 6000 or 8000 |
| Topical ointment base | PEG 400 + PEG 3350/4000 blend |
Not sure which row you are in? Describe your dosage form, your active and the melting behaviour you need and our technical desk will recommend the blend ratio as well as the grades.
Support that goes beyond shipping the drum
What our technical desk will do
- Confirm the glycol test position first. On this product it comes before price, grade or lead time, and we will not quote a pharmaceutical grade without settling it.
- Cross-reference your grade. Macrogol and PEG numbering do not align perfectly across regions, and a wrong equivalence changes your melting profile.
- Ask about preservative and active compatibility. Paraben inactivation and peroxide sensitivity are the two interactions that surprise people most often.
- Help with blend ratios. Suppository and ointment bases are usually two grades, and the ratio is the formulation decision rather than the grade choice.
Regulatory & compliance notes
- Glycol testing obligations rest with you. Several regulators now expect the finished-product manufacturer to verify glycol content on incoming material rather than relying on a supplier certificate. We support that; we do not replace it.
- Compendial monographs differ in detail. USP-NF and Ph. Eur. limits for glycols and residual solvents have changed in recent revisions; we confirm which edition you cite.
- Parenteral and topical uses raise the bar. Residual ethylene oxide and dioxane limits matter more where the route is not oral.
- Excipient change control is yours to manage. Tell us which products this feeds and we will treat source changes as notifiable rather than routine.
None of the above is legal advice — your own regulatory affairs team owns the final compliance position for your import and your filing. What we commit to is accurate product identity data, verified glycol testing and complete documentation to work from.
From enquiry to delivered pallet
Send the specification
Grade or grades (400, 4000, 6000), the pharmacopoeias you cite, 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 with the glycol panel and statement pack. Batch COA shared for your approval before the material is released.
Ship and track
Freight booked, export documents issued, and the consignment tracked through transit and clearance to your plant.
What buyers ask us about Polyethylene Glycol
What do the numbers 400, 4000 and 6000 mean?
What is the difference between PEG and macrogol?
Which grade should I use for a suppository base?
Why are ethylene oxide and dioxane limits on the COA?
What about ethylene glycol and diethylene glycol content?
Is PEG compatible with my active?
What is the minimum order quantity?
How should we store it?
Do you manufacture this yourself?
Request pricing on Polyethylene Glycol
Send your grade or grades, the pharmacopoeias you cite, 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.