Ethyl Chloroformate
A chloroformate is the bridge between an amine and a carbamate, or an alcohol and a carbonate. Ethyl chloroformate is the small, fast-reacting member of that family — reached for whenever the target calls for the ethyl group rather than something bulkier.
Chelora Chemicals supplies ethyl chloroformate to pharmaceutical, analytical and specialty-chemical producers worldwide, in UN-approved packing, with a batch COA and GHS safety data sheet on every consignment.
Product identity
- CAS Number
- 541-41-3
- IUPAC name
- Ethyl carbonochloridate
- Molecular formula
- C₃H₅ClO₂
- Molecular weight
- 108.52 g/mol
- EC / EINECS
- 208-778-5
- UN Number
- 1182 · Class 6.1*
- SMILES
- CCOC(=O)Cl
- HS Code
- 2915 90*
* Confirm the exact UN entry, packing group and HS heading with your freight forwarder and customs broker — classification and the shipping description can differ by mode and country.
What Ethyl Chloroformate is used for
Ethyl chloroformate is a colourless, pungent, corrosive liquid — the ethyl ester of chloroformic acid, with an acyl chloride at one end and an ethoxy group at the other. That combination makes it react fast and cleanly with amines, alcohols and phenols, which is exactly why it is reached for whenever a synthesis needs an ethyl carbamate or ethyl carbonate installed in one step.
Its core use is to introduce the ethyl carbamate protecting group onto amines and to form carbonate esters from alcohols and phenols, both common steps across pharmaceutical intermediate and advanced building-block synthesis. It is also the standard derivatisation reagent for amino acid and fatty acid analysis by GC and GC-MS, and finds use in polymer, coatings and adhesive formulation chemistry.
Where it sits among chloroformate reagents
- Ethyl chloroformate (this product) small, volatile, fast-reacting; the default when the target calls for an ethyl group.
- Methyl chloroformate smaller and more volatile still, used where a methyl carbamate or carbonate is the target.
- Benzyl / isobutyl chloroformate bulkier chloroformates used for different protecting-group chemistry, not interchangeable with this product.
- Chloroacetyl chloride a pre-formed acid chloride rather than a chloroformate ester — a different reaction class. See that page.
On a reactive chloroformate, confirm the CAS number and the assay method on your purchase order — see the full intermediate range.
Appearance and handling character
The material is a flammable, fuming liquid that decomposes slowly in water, releasing ethanol, hydrogen chloride and carbon dioxide, and it attacks many metals in humid conditions. It is toxic by inhalation and severely corrosive to skin and eyes, and it is best kept refrigerated to slow its own slow decomposition. Moisture exclusion, cold storage and vapour control are the three practical requirements on this product.
| Parameter | Typical value |
|---|---|
| Appearance | Colourless to pale yellow liquid |
| Assay (GC) | 98.0% min |
| Boiling point | 93 – 95 °C |
| Free acidity (as HCl) | 0.3% max |
| Moisture | 0.1% max |
| Colour (APHA) | Reported per batch |
Important: the figures above are indicative of commercial-grade material and are offered for planning only. The batch certificate of analysis is the governing document. Assay and moisture carry straight into downstream derivatisation and synthesis yield — tell us your target and we will quote against it.
| Property | Value |
|---|---|
| Physical state | Liquid at ambient |
| Melting point | −81 °C |
| Density | 1.14 g/cm³ (20 °C) |
| Flash point | 16 °C — flammable |
| Water reaction | Decomposes slowly — generates HCl + CO₂ |
| Incompatibilities | Water, alcohols, amines, open flame |
Physical constants compiled from public reference data for CAS 541-41-3 and rounded for readability. Treat them as orientation, not as a specification.
Where our customers put this reagent to work
A versatile small chloroformate with uses spanning synthesis, analysis and materials chemistry.
Pharmaceutical carbamate intermediates
Installs the ethyl carbamate protecting group onto amine intermediates across API and advanced-intermediate synthesis.
- End-use declaration typical
- Full impurity profile on request
- Low-moisture grade available
GC / GC-MS derivatisation reagent
The standard reagent for converting amino acids and fatty acids into volatile derivatives for chromatographic analysis.
- High-purity analytical grade
- Small packs for lab use
- Certified assay on COA
Carbonate ester synthesis
Reacts with alcohols and phenols to give alkyl and aryl carbonate esters used in polymer, coating and adhesive formulation.
- Technical-grade specification
- Bulk quantities available
- Technical desk review of your route
Fine-chemical building block
A general acylating and carbamoylating agent across specialty and fine-chemical synthesis wherever an ethyl handle is needed.
- Colour-critical supply available
- See our full intermediate range
Research & process development
Small-scale use in route scouting and analytical reference work, with the same documentation as the commercial lot.
- Packs from 500 mL
- Full analytical documentation available
- Retained sample held against the lot
Contract & scheduled supply
Pharma intermediate plants consume this continuously. We hold refrigerated inventory and release it against your production calendar.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
How we supply Ethyl Chloroformate
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. On a reagent that decomposes slowly even under ideal storage, owning no plant means we are never defending old stock — we route your order to the producer whose turnaround and cold-chain packing actually matches what your process needs.
We place your order with whichever qualified producer best matches your assay, your moisture and acidity limits, your price point and your delivery window.
We keep a second qualified source on this line, because the short, temperature-sensitive shelf life rules out heavy stockpiling as a buffer against a single plant's turnaround.
- Assay confirmed by GC before we quote. On a reagent used off a nominal percentage, we verify it rather than take the label on trust.
- Free acidity reported. Residual HCl signals partial decomposition and shifts reaction stoichiometry if not accounted for.
- We ask what it feeds before we quote. Pharma-intermediate synthesis and analytical derivatisation carry different documentation expectations.
- Cold-chain packing specified where it matters. This is a specification point on a reagent that benefits from refrigerated transit, not packaging detail.
- Flammability and toxicity classification stated up front. Said at enquiry stage so your EHS team can plan containment before the first drum arrives.
- Export machinery handled in-house. Classification, approved packing, labelling, freight booking and customs paperwork are ours to manage.
Packed the way your plant receives it
On a flammable, moisture- and heat-sensitive liquid the pack is doing chemistry as well as containment. Tell us how the material will be charged and we will quote the format that keeps it stable.
Lined steel drums
UN-approved, corrosion-resistant lined drums with sealed closures — the standard commercial format for bulk transfer.
Refrigerated transit packing
Recommended for this product given its slow intrinsic decomposition — temperature-controlled freight keeps assay stable in transit.
Bulk liquid transport
For contracted tonnage, temperature-controlled ISO tank containers reduce handling and packaging cost per tonne.
Trial / sample quantities
Small, sealed, DG-compliant containers dispatched cold so your R&D team can qualify the grade before committing to larger volumes.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with DG documentation filed before the booking is made.
Campaign despatch
We hold contracted, cold-stored tonnage and release it against your production calendar, minimising time in transit and storage.
Flammability, moisture and respiratory protection are the controlling routes
Ethyl chloroformate is flammable, severely corrosive, and toxic by inhalation. The summary below is orientation only — the safety data sheet supplied with your consignment is the authoritative document.
Classified hazards
H225Highly flammable liquid and vapour.H330Fatal if inhaled.H302Harmful if swallowed.H314Causes severe skin burns and eye damage.—Decomposes in water, releasing ethanol, HCl and CO₂.—Attacks many metals in the presence of moisture.
Hazard statements reflect classifications commonly published for CAS 541-41-3. Always read the SDS issued with your specific batch.
Spill & emergency orientation
Plan your response before the pallet arrives. Sections 4, 5 and 6 of the SDS are the authoritative instructions and should be posted at the point of use.
- Eliminate ignition sources immediately. Flash point of 16 °C means vapour can ignite at everyday ambient temperatures — this is a fire hazard as much as a toxic one.
- Do not flush a spill with large volumes of water. It decomposes slowly releasing HCl gas; use dry absorbent or a designated controlled-quench procedure.
- Evacuate and ventilate before re-entry. Fuming and toxic vapour release make this a respiratory hazard beyond the immediate spill area.
- Contain, do not hose to drain. Collect the material and dispose of it as regulated chemical waste under controlled neutralisation.
- Treat any skin or eye contact as an emergency. H314 means irrigate immediately and seek medical attention without delay.
Storage
- Refrigerated storage, 0–10 °C. This reagent decomposes gradually even when dry and sealed; cold storage meaningfully extends usable shelf life.
- Keep containers tightly closed under dry conditions. A part-used drum left open in humid air will fume and corrode its own closure.
- Keep away from ignition sources. Flammable vapour forms readily at ambient temperature; store in a flammables-rated area.
- Segregate from water, alcohols, amines and strong oxidisers. All react; keep them apart by distance, not just by label.
- Shelf life typically 12–18 months refrigerated. Shorter at ambient temperature. Re-assay and check acidity before use after extended storage.
Handling & PPE
- Design vapour and skin contact out. Closed transfer, contained charging and local exhaust ventilation first; PPE last, never as the sole control.
- Acid-resistant gloves, face shield and chemical-resistant suit. With contaminated clothing removed, bagged and handled as contaminated waste.
- Supplied-air or full-face respiratory protection. Required for any operation where fuming or vapour release is possible — H330 is fatal-if-inhaled, not a minor irritant.
- Bond and ground equipment during transfer. Standard practice for a flammable liquid at this flash point.
- Never discharge to drain or watercourse. Contain and dispose of as regulated chemical waste.
Transport
Ethyl chloroformate ships as regulated cargo under UN 1182, Class 6.1 (Toxic) with Class 3 flammable and Class 8 corrosive subsidiary risks, Packing Group I, Inhalation Hazard Zone B. We classify each consignment, apply UN-approved packaging and labelling, and file the dangerous-goods declaration before the booking is made — ask us for the current DG paperwork when you plan the shipment.
What travels with every consignment
A chemical shipment is only as good as the file that travels with it. Verifying what the source plant sends is precisely the work you are buying from a supplier.
Certificate of Analysis
Batch-specific assay, free acidity, moisture and colour — checked against your specification before release.
GHS Safety Data Sheet
Full 16-section SDS in GHS format covering hazards, exposure controls, handling, storage, spill response, toxicology and disposal, in the language your destination requires.
Dangerous Goods Declaration
UN number, hazard class, subsidiary risks and IMDG or RID/ADR declaration prepared and filed before the container is booked.
Analytical method & chromatogram
GC method and batch chromatogram on request, so your QC can reproduce the impurity profile rather than take it on trust.
Certificate of Origin
Chamber-attested where required, plus preferential-origin forms where a trade agreement gives your import duty relief.
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 molecule, two reaction families
Whether the product is a carbamate or a carbonate depends only on whether the incoming nucleophile is a nitrogen or an oxygen. The pattern below is general background, not a process disclosure.
Nucleophile attacks the carbonyl
An amine, alcohol or phenol attacks the electrophilic carbonyl carbon, displacing chloride as the leaving group.
Form carbamate or carbonate
With an amine, the product is an ethyl carbamate; with an alcohol or phenol, an unsymmetrical carbonate ester.
Scavenge the released acid
A base is typically present to neutralise the hydrogen chloride released, driving the reaction to completion cleanly.
Isolate the product
The carbamate or carbonate product is isolated by standard work-up, often without further purification needed.
Why assay and acidity carry through
On this reagent, two drums at the same nominal label can give very different downstream results:
- Assay sets your stoichiometry. A reagent used off a nominal percentage will under- or over-react if the real titre has drifted from the label.
- Free acidity signals partial decomposition. Elevated HCl content means some of the reagent has already hydrolysed before it reaches your process.
- Purity matters directly in derivatisation. For GC/MS work, trace impurities in the reagent itself can appear as spurious peaks in the chromatogram.
- Colour carries into the finished intermediate. Degraded material produces coloured by-products that can persist through the reaction.
That is why we quote against your written assay and acidity limits rather than a generic "technical grade", and why the batch COA is shared for approval before dispatch rather than sent with the invoice.
| Material | Role |
|---|---|
| Ethyl chloroformate CAS 541-41-3 — this product | Ethyl carbamate / carbonate |
| Thionyl chloride CAS 7719-09-7 | Separate chlorinating agent |
| Chloroacetyl chloride CAS 79-04-9 | Pre-formed acid chloride |
| Hydroxylamine sulfate CAS 10039-54-0 | Separate reducing-agent family |
We supply across this reagent family — see the full intermediate range. Send the CAS number and we will confirm the correct material 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.
Ethanol and phosgene-route feedstock
Production depends on ethanol and a carbonylating agent, so agricultural ethanol and chlor-alkali markets feed through.
- Ethanol tracks agricultural feedstock cost
- Chlorine chemistry follows chlor-alkali economics
- We flag feedstock-driven moves in the quote
Pharma intermediate demand
A broad range of carbamate-protected intermediates depends on this reagent, so demand tracks the pharma manufacturing cycle.
- Demand is broad-based, not single-product
- Contracted call-off smooths the exposure
- We hold a second qualified source
Purity specification
A technical grade and a tightly specified analytical-derivatisation or pharma grade are different products from the same plant at different prices.
- Tell us the real limits, not a wish list
- We will say when a wider spec will do
- Over-specification is the commonest cost leak
Cold-chain freight and DG surcharges
Class 6.1 PG I cargo with flammable and corrosive subsidiary risks carries a hazardous surcharge, and refrigerated transit adds cost on top.
- Compare on landed cost, not ex-works
- DG and cold-chain space books out early
- We quote FOB, CIF, CFR or DDP as you prefer
Source concentration
Production is concentrated among a limited number of plants with the cold-chain capability this product needs, so turnarounds move the market.
- We hold a second qualified source on this line
- Qualify the alternate before you need it
- Ask us about dual-source contracts
Shelf life and inventory risk
A 12 to 18 month shelf life, shorter at ambient temperature, means stockpiling against a price move carries a real degradation cost.
- Buy to schedule rather than to price
- We hold inventory and release on call-off
- Ask about scheduled despatch
| If your end use is… | Specify |
|---|---|
| Pharma carbamate intermediate | Low moisture, full impurity profile |
| GC / GC-MS derivatisation | High-purity analytical grade |
| Carbonate / polymer chemistry | Technical grade |
| Fine-chemical building block | Colour-critical |
| Laboratory / reference use | Small DG-compliant pack, full COA |
Not sure which row you are in? Describe what you make from it and our technical desk will recommend the grade — including telling you when a cheaper specification would do the job just as well.
Support that goes beyond shipping the drum
What our technical desk will do
- Confirm assay and acidity limits before anything else. On this reagent both carry into downstream yield and quality, and we settle them in the first reply.
- Ask what it feeds. Pharma carbamate synthesis and analytical derivatisation carry different documentation expectations.
- Recommend cold-chain packing where it matters. Refrigerated transit is worth the cost on some routes and unnecessary on others, and we will say which.
- Be straight about the flammability and toxicity classification. Stated at enquiry stage so your EHS team can plan containment before the first delivery.
Regulatory & compliance notes
- Import controls vary by destination. We check destination rules before quoting, not after you have raised the PO.
- Chemical inventory listings differ between regions. We will supply the identity data you need for that filing.
- Effluent and waste rules matter. Corrosive, acidic waste streams require controlled neutralisation before discharge; check your consent against the material.
- End-use declarations may be requested. Some destinations ask for a stated end use on reactive chloroformates; we will tell you if yours does.
None of the above is legal advice — your own regulatory affairs team owns the final compliance position for your import and your workplace. What we commit to is accurate product identity data, an honest statement of the hazard classification and complete documentation to work from.
From enquiry to delivered pallet
Send the specification
Product name or CAS 541-41-3, your assay and acidity limits, quantity, pack preference and destination port.
Receive a firm quote
Pricing, lead time, cold-chain packing and Incoterm confirmed in writing within 24 hours — our sourcing desk is staffed around the clock.
Qualify and approve
Sample dispatched refrigerated if you are qualifying a new source. Batch COA shared for your approval before the material is released.
Ship and track
Classification filed, DG freight booked, export documents issued, and the consignment tracked through transit and clearance.
What buyers ask us about Ethyl Chloroformate
What is ethyl chloroformate used for?
How is it different from other chloroformates?
What purity do you normally supply?
Is it hazardous?
What is the minimum order quantity?
How should we store it?
Is this a dangerous good? What paperwork comes with it?
Do you manufacture this yourself?
Request pricing on Ethyl Chloroformate
Send your required assay and acidity limits, 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 cold-chain packing options.