Trimethylamine CAS 75-50-3

What is Trimethylamine?

Trimethylamine is the fully methylated member of the methylamine family — three methyl groups on a single nitrogen, (CH₃)₃N. It is a tertiary amine, which is the single most important thing to know about it commercially: with no N-H bond left, it cannot form amides or imines, and its chemistry runs almost entirely through the lone pair on nitrogen.

At ambient conditions it is a colourless gas, boiling at about 3 °C, with the unmistakable odour of decaying fish — trimethylamine is in fact the compound responsible for that smell in spoiled seafood. The odour threshold sits in the low parts per billion, far below any hazardous concentration, so a handling area will smell of it long before anyone is at risk. That is a useful warning property and a persistent nuisance in equal measure.

Most buyers take it as a liquid rather than a gas. The common commercial forms are 30% and 45% aqueous solutions and 25–33% solutions in methanol, all of them clear, colourless, strongly alkaline liquids. Anhydrous material is shipped as a liquefied gas under pressure and is used where water would interfere with the downstream reaction.

Almost all of the world's trimethylamine goes into one reaction: quaternisation. Adding a fourth group to the nitrogen gives a permanently charged quaternary ammonium cation, and that cation is the active structure in choline chloride, in cationic surfactants and fabric softeners, in strong-base ion-exchange resins and in cationic starches. Choline chloride for animal feed alone accounts for the largest share of global demand.

Why trimethylamine specifically

• No N-H bond. Being fully substituted, it cannot be acylated to an amide. Its value lies in the fourth bond it can form to nitrogen, which converts it to a permanently cationic quaternary salt.
• Clean quaternisation. Reaction with alkyl halides, epoxides or dimethyl sulphate is fast, high-yielding and leaves no secondary amine to carry through, which matters in feed-grade and personal-care chemistry.
• Volatile and easy to strip. A boiling point near 3 °C means unreacted amine can be recovered and recycled rather than ending up as an impurity in the product.
• Low odour threshold. Detectable in the parts-per-billion range. That makes it a standard warning odorant for otherwise odourless gases, and it is why trace carry-over into a consumer product is unacceptable even at levels no analytical spec would flag.

How TMA is Manufactured

Trimethylamine is produced continuously from methanol and ammonia on the same plant that makes mono- and dimethylamine. What distinguishes one supplier's product from another is how cleanly the separation train runs, not the reaction chemistry.

• Amination. Methanol and ammonia are passed over an acidic silica-alumina or zeolite catalyst at roughly 350–450 °C and 20–30 bar. Water is eliminated and an equilibrium mixture of mono-, di- and trimethylamine leaves the reactor with unconverted ammonia and methanol.
• Equilibrium shift. The thermodynamic equilibrium naturally favours the more substituted amines, so a plant configured for trimethylamine recycles less and runs at a higher methanol-to-ammonia ratio than one optimised for the mono product.
• Extractive distillation. Trimethylamine forms azeotropes with both ammonia and water, so it cannot be taken out by ordinary fractionation. Extractive distillation with water breaks the azeotrope and delivers the trimethylamine cut. This is the technically demanding part of the plant.
• Finishing. The product is either liquefied under pressure as anhydrous trimethylamine or absorbed into demineralised water to give 30% or 45% solution. Methanolic solutions are prepared the same way where the downstream chemistry prefers an organic medium.

Typical Commercial Specification

Figures below are representative of anhydrous commercial grade and of the common aqueous solutions. Feed-grade and low-secondary-amine grades are available — send us the specification you work to and we will quote against it.

Physical & Chemical Properties

Reactivity in practice

With no replaceable hydrogen on nitrogen, trimethylamine's chemistry is narrower than that of the primary and secondary amines — but what it does, it does extremely well:

• Quaternisation with alkyl halides. Reaction with methyl chloride, benzyl chloride or a long-chain alkyl halide gives a quaternary ammonium salt directly. This is the route to cationic surfactants, biocides and phase-transfer catalysts.
• Reaction with epoxides. Ethylene oxide opens onto the nitrogen to give choline, which is isolated as choline chloride — by volume the single largest outlet for trimethylamine worldwide.
• Reaction with chloroacetic acid. Gives betaine (trimethylglycine), used as an osmolyte in feed, as a mild amphoteric surfactant and in personal care.
• Salt formation. As a base it forms stable salts with mineral acids. The hydrochloride is a convenient low-odour solid form for handling and shipping where the free amine would be impractical.

Trimethylamine vs Dimethylamine vs Monomethylamine

The three methylamines come off the same reactor and are often quoted together, but they are not interchangeable. The number of methyl groups already on the nitrogen decides how many N-H bonds remain, and that decides what chemistry is available downstream.

Stated plainly: trimethylamine has no N-H bond and is used almost entirely for quaternisation; dimethylamine keeps one and is the route to dialkyl amide solvents such as DMF; monomethylamine keeps two and can still form amides, imines and N-methyl heterocycles. Substituting one for another is a reformulation, not a swap. Chelora supplies all three.

Industries We Supply TMA To

The same molecule leaves our warehouse for very different factories. What changes between them is not the CAS number but the form, the solution strength, the packing and the documentation each sector expects.

Where TMA is Used

Trimethylamine is a single-purpose workhorse: nearly everything it is bought for involves putting a fourth group on the nitrogen. These are the end uses our customers buy it for, roughly in order of volume.

In choline chloride manufacture

The dominant global outlet. Trimethylamine is reacted with ethylene oxide in the presence of hydrochloric acid to give choline chloride, which is sold as a 70–75% aqueous solution or dried onto a silica or corn-cob carrier for feed use. Feed producers care about two things on the amine certificate: secondary amine carry-over, which produces off-spec by-products, and residual odour, since a feed mill cannot tolerate a persistent fishy smell in its finished product.

In quaternary ammonium chemistry

Quaternisation with a long-chain alkyl halide gives the cationic surfactants behind fabric softeners, hair conditioners and a large family of disinfectants and sanitisers. The reaction is clean and high-yielding, but any secondary amine in the feedstock ends up as an unquaternised tertiary amine in the finished product — detectable by odour long before it is detectable by assay, which is why personal-care customers specify tightly.

In ion-exchange resin production

Type I strong-base anion resins are made by quaternising a chloromethylated styrene-divinylbenzene bead with trimethylamine. The resulting quaternary sites are permanently charged and work across the whole pH range, which is what makes these resins the standard for demineralisation, condensate polishing and ultrapure water production.

In papermaking chemistry

Cationic starches improve retention, drainage and dry strength at the wet end of a paper machine. Trimethylamine-derived quaternising agents put the positive charge on the starch backbone so it can anchor to the negatively charged cellulose fibre.

Quality Control & Testing

Every lot is released against a batch-specific Certificate of Analysis. The methods behind the numbers are standard across the industry, and we are happy to share them or to work to your own in-house test protocol.

• Assay and amine distribution — gas chromatography, which resolves tri-, di- and monomethylamine and quantifies residual ammonia and methanol in one run.
• Strength of solution — acid-base titration against standardised acid, the figure that governs your charge calculation on an aqueous or methanolic grade.
• Water content — Karl Fischer titration on anhydrous material, where water would interfere with the downstream quaternisation.
• Colour — APHA / Hazen against a standard. Colour drift usually signals oxidation or metal pickup in storage or transfer.
• Metals — iron in particular, since it catalyses discolouration and is undesirable in feed and ion-exchange applications.
• Odour check — a simple sensory check against a retained standard. For feed and personal-care routes this catches carry-over that an assay will not.

Common Process Problems & Likely Causes

When trimethylamine misbehaves in a plant, the cause is usually one of a short list of things. This table is the shortcut our technical desk works through before anyone opens a complaint file.

Packaging, Storage & Shipping

• Solution packing. 200 L HDPE or lined steel drums, 1000 L IBCs, and bulk road or ISO tank loads for continuous users.
• Anhydrous packing. Pressurised cylinders, tonne containers and ISO tanks, handled as a liquefied flammable gas.
• Storage. Cool, shaded, well-ventilated area away from heat, ignition sources, oxidisers and acids. Keep containers closed and store solutions below 30 °C where possible.
• Materials of construction. Stainless steel, carbon steel or suitable lined vessels. Avoid copper, brass, bronze, aluminium and mercury.
• Odour management. Vents, relief discharges and drum-breathing points should be routed to a scrubber or carbon filter. The odour threshold is low enough that an unscrubbed vent will be noticed well beyond the site boundary.
• Shelf life. Typically 12 months in unopened original packing under those conditions. Beyond that, re-test rather than assume.
• Transport classification. Anhydrous: UN 1083, Trimethylamine anhydrous, Class 2.1. Aqueous solution: UN 1297, Trimethylamine aqueous solution, Class 3 with subsidiary risk 8; packing group depends on concentration.
• Container loading. Palletised and secured for FCL; LCL consolidation and tank arrangements available by volume.

Hazards & Safe Handling

Trimethylamine is a flammable, corrosive gas and must be handled by trained personnel under a proper risk assessment. The classifications below are indicative — the current SDS supplied with your consignment is the governing document.

• Exposure control. Handle in a closed system or under local exhaust ventilation. Gas-detection and alarm cover is standard practice where anhydrous material is used.
• PPE. Chemical-resistant gloves, chemical goggles and face shield, chemical-resistant clothing, and respiratory protection suited to the task. Full-face protection for any transfer operation.
• Ignition control. Vapours are extremely flammable and form explosive mixtures with air. Bonded, earthed and explosion-proof equipment, and no ignition sources in the zone.
• Incompatibilities. Strong oxidising agents, strong acids, mercury, and copper, brass, bronze and aluminium equipment.
• Spill response. Evacuate and ventilate. Water spray knocks down vapour; contain run-off. Collect absorbed material in a labelled closed container. Do not wash to drain.
• Environment. Do not allow to enter drains, surface water or groundwater. Dispose through a licensed chemical waste contractor.
• Fire. Extremely flammable. Stop the flow if it can be done safely, cool exposed containers with water spray from a protected position, and use self-contained breathing apparatus — decomposition releases nitrogen oxides.
• First aid. Move to fresh air, remove contaminated clothing immediately, wash skin with plenty of water, flush eyes for at least 15 minutes, and seek medical attention with the SDS to hand.

Regulatory & Compliance Notes

Trimethylamine is a long-established industrial chemical and is listed on the major national chemical inventories. Because obligations differ by territory, volume and use, the notes below are orientation rather than legal advice — confirm your own position with your regulatory adviser before importing.

• Inventory status. Listed on the principal chemical inventories in the major importing regions. Ask us for the inventory confirmation relevant to your destination country.
• Feed-chain use. Where the material is destined for choline chloride or betaine production for animal feed, expect additional declarations on origin, traceability and permitted additives under the feed legislation in force at destination.
• Import registration. Several territories require the importer to hold a registration or notification before a consignment lands. Start that process early — it is the most common cause of delay at destination.
• Hazard communication. Supplied with an SDS compliant with the format applicable to your region, and labelled in line with the GHS classification for the product.
• Dangerous goods. UN 1083 (anhydrous, Class 2.1) or UN 1297 (aqueous solution, Class 3 / 8). Declarations prepared for IMDG (sea) or IATA (air) as appropriate to the mode.
• Workplace exposure and odour. Occupational exposure limits apply in most jurisdictions. Note that the odour threshold is orders of magnitude below the limit, so smell is not a measure of exposure — monitor against the limit, not the nose.

We Supply TMA Worldwide

Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Trimethylamine from India to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, dangerous-goods paperwork and freight so the material arrives ready to use.

• Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
• Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other Indian ports arranged where it suits the routing.
• Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and dangerous-goods declaration issued as a complete set.
• Flexible volumes. A single drum for laboratory qualification, through LCL consolidations, up to repeat full loads on a supply contract.
• Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.

Buying TMA from Chelora

We are an independent sourcing and supply partner. For trimethylamine that means matching the form and the grade to the application — anhydrous for a dry, pressure-rated plant, 30% or 45% aqueous for a general batch facility, a low-secondary-amine cut for feed and personal-care routes — rather than selling whatever happens to be in the tank.

• Documentation on every lot. Batch-specific COA, current SDS and TDS issued with the consignment, not weeks afterward.
• Samples before commitment. Trial quantities for process qualification ahead of a commercial order.
• Quantities. From a single drum through to tank loads and ongoing contract supply.
• Export experience. Dangerous-goods documentation, packing and labelling handled for sea and road freight to any destination.
• Technical support. Direct access to people who know the chemistry, for questions on amine distribution, odour control or materials compatibility.
• Related intermediates. Methylamine, dimethylamine, the ethylamines and the wider aliphatic amine range from one supplier.

How ordering works

• Send the enquiry. Product, grade or specification, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
• We quote. Price, lead time, packing and a sample COA, normally within one working day.
• Sample and qualify. For first orders or critical applications, we send a trial quantity so your lab can sign off before you commit.
• Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
• Production and QC. Material allocated and released against a batch-specific COA, with a pre-shipment sample where the application calls for it.
• Ship and document. Packed, labelled and loaded with the full export and dangerous-goods document set, and tracked through to arrival.

Related Amines & Intermediates

Buyers of trimethylamine usually source several of these alongside it. Consolidating them on one order cuts freight cost and gives you a single point of contact for documentation.