| HS Code | |
| Productname | Chloromethane |
| Iupacname | Chloromethane |
| Othernames | Methyl chloride, R-40, HCC 40 |
| Chemicalformula | CH3Cl |
| Molecularweight | 50.49 g/mol |
| Casregistrynumber | 74-87-3 |
| Ecnumber | 200-817-4 |
| Appearance | Colorless gas |
| Odor | Faint, sweet, ether-like |
| Meltingpoint | -97.7 °C |
| Boilingpoint | -23.8 °C |
| Density | 1.003 g/cm³ at -24 °C (liquid) |
| Solubilityinwater | 5.32 g/L at 25 °C |
| Vaporpressure | 4.9 atm at 20 °C |
| Flashpoint | -46 °C |
| Autoignitiontemperature | 625 °C |
| Explosivelimits | 7.0–19.0% in air |
| Dipolemoment | 1.896 D |
As an accredited Chloromethane factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Chloromethane is packaged as a liquefied, flammable gas in sealed, pressure-rated steel cylinders, typically containing 10 kg per cylinder. |
| Container Loading (20′ FCL) | Chloromethane (UN 1063), flammable liquefied gas, loaded into 20-foot FCL via approved pressure cylinders or ISO tank under IMDG rules. |
| Shipping | Chloromethane (methyl chloride), UN 1063, is shipped as a liquefied flammable gas in approved pressure cylinders. Use Class 2.1 labels, secure upright, ventilate, avoid heat/ignition/oxidizers. Follow DOT/IMDG/IATA rules; provide shipping papers, emergency response information, and trained personnel. Toxic by inhalation; prevent leaks. Use only approved packaging and handling equipment. |
| Storage | Store chloromethane as a pressurized liquefied gas in cool, dry, well-ventilated areas away from heat, sparks, open flames, and direct sunlight. Keep cylinders upright, secured, and valve-protected. Separate from oxidizers, acids, alkalis, and reactive metals. Use explosion-proof equipment, leak detection, grounding, and ventilation. Follow local regulations; keep containers closed and inspect regularly for leaks or corrosion. |
| Shelf Life | Chloromethane is stable; shelf life is indefinite if stored as a compressed liquefied gas, cool, dry, and away from ignition sources. |
The largest industrial outlet for chloromethane is the direct synthesis of methylchlorosilanes by gas–solid reaction with silicon metal. In this process, chloromethane vapour is fed continuously into a fluidized bed reactor charged with metallurgical-grade silicon powder and a copper-based catalyst system. Reported copper loadings of 2–10 wt% relative to silicon feed are used, with promoter metals such as zinc, tin, or aluminium added at concentrations below 1 wt% to suppress methyltrichlorosilane formation and favour dimethyldichlorosilane. The reactor is typically operated between 250 °C and 320 °C under 1–4 bar gauge; published data for this specific configuration is limited because catalyst activation and hot spot migration depend on silicon particle size distribution, surface oxide content, and fluidization gas velocity. The hot product gas is quenched, filtered, and routed to fractional distillation. Dimethyldichlorosilane is hydrolyzed to linear and cyclic siloxanes, then polymerized to silicone fluids, elastomers, and resins. Downstream food-contact silicone rubber is governed by FDA 21 CFR 177.2600 for repeated-use rubber articles, while industrial registration falls under REACH EC 1907/2006. Operational limits include moisture ingress, which generates hydrogen chloride and promotes gel formation in downstream hydrolysis; incoming chloromethane must be dried to 10 mg/kg or below, and silicon fines require explosion hazard control in the classifier and dust-handling systems.
| Silane component | Structural formula | Reported crude distillate range | Primary downstream consuming sector |
|---|---|---|---|
| Dimethyldichlorosilane | (CH3)2SiCl2 | 70–85% | Silicone fluids, elastomers, resins |
| Methyltrichlorosilane | CH3SiCl3 | 5–15% | Crosslinker and silane intermediates |
| Trimethylchlorosilane | (CH3)3SiCl | 2–8% | End-capping agent, silylation reagent |
| Methylhydrogenodichlorosilane | CH3HSiCl2 | 1–5% | Hydrosilylation, water-repellent finishes |
In low-temperature cationic copolymerization of isobutylene with isoprene, liquid chloromethane functions simultaneously as slurry diluent, heat-transfer fluid, and inert reaction medium. The boiling point of -24.2 °C allows evaporative cooling to maintain the reaction temperature between -100 °C and -85 °C in a continuous stirred-tank reactor without freezing the polymer slurry. Initiation is achieved with aluminum chloride or alkylaluminum chloride dissolved in dry chloromethane. Moisture and oxygen poison the catalyst; bulk chloromethane entering the polymerization loop is typically controlled to 10 mg/kg water and 5 ppm oxygen. Isoprene incorporation is held between 1.0 mol% and 3.0 mol% to provide controlled unsaturation for subsequent halogenation. Molecular weight is tracked as Mooney viscosity per ISO 289-1:2017, ML 1+8 at 125 °C, with commercial grades spanning 20–80 MU and batch specification windows commonly at ±4 MU. The resulting copolymer is classified under ASTM D1418-21 as IIR before halogenation and as BIIR or CIIR after bromination or chlorination. End products include tire inner liners, curing bladders, pharmaceutical stoppers, and protective clothing. Pharmaceutical stoppers are subject to USP <381> for elastomeric closures for injections, while repeated-use rubber articles must satisfy FDA 21 CFR 177.2600. Operational boundaries include limited solubility of high-molecular-weight polymer in cold chloromethane; if reactor temperature drifts above -85 °C, agglomeration and fouling of the slurry discharge line increase rapidly.
Quaternization of alkyl dimethylamines with chloromethane is performed in a stirred pressure vessel equipped with subsurface gas injection, jacket cooling, and a closed headspace routed to caustic scrubbers. Typical reaction conditions are 70–100 °C and 0.3–0.7 MPa gauge, with chloromethane molar excess of 5–20% and reaction time from 4 h to 12 h. Isopropanol or a methanol/water mixture is selected as solvent, with water content controlled below 0.5% to limit chloromethane hydrolysis to methanol and hydrogen chloride, which would depress quaternization yield by protonating the amine. The reaction is terminated when residual tertiary amine falls below 1% of initial charge by acid titration. Dodecyldimethylamine yields dodecyltrimethylammonium chloride, a cationic surfactant and biocide. End products include disinfectant formulations, fabric softeners, antistatic agents, and corrosion inhibitors. Biocidal products require authorization under EU 528/2012, while food-contact sanitizer uses are evaluated under FDA 21 CFR 178.1010. Bactericidal activity claims for quaternary ammonium formulations are supported by EN 1276:2019 suspension testing. A process limitation is the presence of residual alkyl chloride by-products from incomplete amine alkylation; these must be removed by vacuum stripping before the product is sold into personal-care or food-contact applications.
Slurry-phase methylation of alkalized cellulose uses chloromethane as the primary methylating agent in the production of methylcellulose and hydroxypropyl methylcellulose. Cellulose pulp is first alkalized with sodium hydroxide, then reacted with chloromethane in a pressure vessel at 60–90 °C under oxygen-free conditions. Degree of substitution is controlled by the molar ratio of chloromethane to anhydroglucose units and by caustic concentration; water-soluble methylcellulose typically has a degree of substitution of 1.5–2.0 and a methoxy content of 27–32%. Side reactions include hydrolysis of chloromethane to methanol and formation of dimethyl ether, both of which consume caustic and reduce methylation efficiency. The product is slurried, neutralized, washed, dried, and milled. Viscosity is measured on 2% aqueous solution using a Brookfield rotational viscometer per ASTM D1347-14. Compliance for food use is established under FDA 21 CFR 182.1480, and pharmaceutical grades are controlled by USP/NF monographs for methylcellulose and hypromellose. End products include water-retention additives for dry-mix mortars, food thickeners, tablet binders, and hydrophilic film coatings. Operational boundaries include poor filtration at viscosity grades above 50,000 mPa·s, and residual chloride must be washed to specification because chloride interferes with construction-grade set retarders and with pharmaceutical disposal limits.
Chloromethane reacts with aqueous sodium hydrosulfide in a pressurized liquid-phase reactor to form methanethiol and sodium chloride. The reactor is operated at 70–100 °C and 0.5–1.5 MPa gauge, with pH maintained above 10 to keep sulfide in nucleophilic form and minimize release of hydrogen sulfide. Chloromethane is sparged continuously, and methanethiol is stripped as a gas; the crude stream is condensed and distilled to remove dimethyl sulfide, which forms by sequential methylation. Byproduct sodium chloride brine is recovered or routed to wastewater treatment with chloride discharge limits applied under local permitting. Methanethiol is an intermediate for methionine, an animal feed supplement regulated in the European Union under EU 1831/2003, and for organophosphorus agrochemical intermediates. The process is economically constrained by the need to manage methyl mercaptan odour at airborne concentrations below 0.5 ppb; closed vent systems, thermal oxidizers, and caustic scrubbing are required at storage and transfer points. Published data for this specific configuration is limited because methanethiol producers often operate captive units integrated with methionine or pesticide assets.
N-Methylation of tertiary amine intermediates with chloromethane is restricted to pressure-rated cGMP campaigns where the need for high methylating efficiency justifies gas handling and residual solvent control. The reaction is typically conducted in a glass-lined or stainless stirred autoclave at 40–80 °C and 0.2–0.5 MPa gauge, using acetonitrile, acetone, or isopropanol as solvent. A tertiary amine substrate is charged with solvent, and chloromethane is introduced through a mass-flow-controlled dip tube; after reaction, excess chloromethane is degassed and the quaternary ammonium intermediate is precipitated by addition of methyl ethyl ketone or acetone. Residual chloromethane in the isolated intermediate is measured by headspace gas chromatography using a method derived from Ph. Eur. 2.4.24, with reporting thresholds dependent on the final drug substance monograph. Production is governed by ICH Q7 for active pharmaceutical ingredients, including line clearance, change control, and impurity profile documentation. Because the resulting quaternary ammonium salt is often highly hygroscopic, moisture in solvent must be controlled below 0.2% to prevent lattice hydration and inconsistent drying. Published data for this specific configuration is limited; process limits are typically established internally during development and are not disclosed in pharmacopoeial monographs.
Competitive Chloromethane prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8618136850665 or mail to admin@ascent-chem.com.
We will respond to you as soon as possible.
Tel: +8618136850665
Email: admin@ascent-chem.com
Flexible payment, competitive price, premium service - Inquire now!
As a liquefied gas with a vapour pressure of approximately 490 kPa at 20 °C and a normal boiling point of -24.2 °C at 101.3 kPa, chloromethane (CH3Cl, CAS 74-87-3) is supplied as the technical-grade model designation MC-99.5 in steel cylinders, ISO tank containers, and bulk pressure vessels. The substance has a molecular mass of 50.49 g/mol, a liquid density of approximately 0.92 g/cm³ at 20 °C, and a flammability range in air of 8.1–17.4 vol%. Chloromethane is registered under EINECS 200-817-4. In contrast to dichloromethane, chloroform, and carbon tetrachloride, chloromethane is stored as a pressurised liquefied gas and is shipped as UN 1063, Class 2.1. Because it is gaseous at ambient pressure, chloromethane is not a direct substitute for dichloromethane in open-top vapour degreasing equipment. Its industrial value is as a pressurised methylating feedstock and low-temperature polymerisation diluent. The main commercial uses are methyl chlorosilane production, butyl rubber polymerisation, quaternization of tertiary amines, and cellulose ether methylation. A representative specification for MC-99.5 is given in Table 1.
| Parameter | Limit | Test method |
|---|---|---|
| Chloromethane assay | ≥ 99.5 wt% | GC-FID with Al2O3/KCl PLOT column |
| Water | ≤ 50 mg/kg | ASTM E203-16 |
| Acidity as HCl | ≤ 10 mg/kg | ASTM D2989-01 |
| Nonvolatile residue | ≤ 20 mg/kg | ASTM D2109-01 |
| Methanol | ≤ 50 mg/kg | GC-FID |
| Sulphur compounds | ≤ 1 mg/kg | GC-SCD after cryofocusing |
The assay is determined by gas chromatography with flame ionisation detection using a 0.32 mm × 30 m PLOT column and a pressure-compensated liquid sampling valve. Water is measured by ASTM E203-16 volumetric Karl Fischer titration. Acidity is determined on an aqueous extract using ASTM D2989-01 to avoid interference from the weakly acidic chloroalkane matrix. Nonvolatile residue is measured by evaporation of 100 mL of liquid sample in a platinum dish at 105 °C according to ASTM D2109-01. These methods are specified on the certificate of analysis for each batch. Higher-purity grades with moisture below 10 mg/kg are available for specialised electronics applications; published data for those grades is limited to supplier certificates of analysis rather than standardised product specifications.
In fluidised-bed methyl chlorosilane production, chloromethane reacts with a silicon-copper contact mass at 280–340 °C and 0.1–0.5 MPa. The feed is vaporised through shell-and-tube heat exchangers with 316L tubes and distributed through a multi-nozzle sparger into a bed of silicon particles. Copper in the contact mass is typically 2–5 wt%. Water in the methyl chloride feed is a kinetic poison; it hydrolyses chlorosilanes in the reactor freeboard and oxidises the active copper-silicon alloy surface. The moisture limit of 50 mg/kg is therefore applied before vaporisation, with liquid feed passed over molecular sieve 3A or activated alumina dryers. Published plant data for the exact selectivity loss as a function of feed moisture is limited, but the patent literature identifies water as a primary contact-mass deactivator. In production-scale beds of 2.0–4.0 m diameter, moisture breakthrough reduces dimethyldichlorosilane selectivity and increases by-product silane and hydrogen chloride formation. The drying step is monitored by Karl Fischer titration of the feed after the dryer; a rise above 30 mg/kg triggers dryer regeneration, while 50 mg/kg is the maximum allowable feed limit. The methyl chloride is superheated to avoid aerosol carryover, and the sparger is fabricated from 316L to resist chloride stress corrosion. Feed moisture is not a commercial purity target but a boundary condition for viable catalyst life and reactor freeboard integrity.
At -98 °C in a stirred slurry reactor, chloromethane serves as the dilution medium for the cationic copolymerisation of isobutylene and isoprene to butyl rubber. The reactor system is a jacketed continuous stirred tank with a polymer loading of 10–20 wt% in the chloromethane slurry. Initiation is achieved with a Lewis acid co-initiator, typically aluminium chloride dissolved in a small methyl chloride stream. Because methyl chloride has a boiling point of -24.2 °C, solvent recovery is accomplished by flashing the reactor effluent and steam stripping residual solvent from the rubber crumb at 60–80 °C. Dichloromethane, by comparison, has a boiling point of 39.6 °C and would require higher recovery temperatures, increasing energy input and the risk of polymer degradation. A limitation of chloromethane in this service is flammability; the reactor building is electrically classified, and gas detection is set to alarm at 10% of the lower explosive limit. The liquid feed is maintained at a moisture content below 50 mg/kg to prevent hydrolysis of the Lewis acid initiator and to reduce corrosion of 316L reactor internals. Batch-to-batch variability in butyl rubber Mooney viscosity is controlled by reactor temperature and monomer conversion rather than by diluent type, but methyl chloride recovery efficiency directly affects monomer loss and energy cost.
Batch methylation of trimethylamine with chloromethane is performed in glass-lined or 316L stainless steel autoclaves at 60–90 °C and 0.4–0.8 MPa. Methyl chloride is fed through a mass flow controller to maintain a 5–10 mol% excess relative to the amine charge. The reaction is exothermic, and the jacket cooling system is sized to limit the temperature rise to 2–3 °C/min during the initial charge. Cycle time is typically 6–12 h. The reactor agitator uses a double mechanical seal with an inert-gas barrier to prevent flammable gas leakage. Before methyl chloride introduction, the headspace is inerted to an oxygen concentration below 5 vol%. The agitator tip speed is specified by the reactor vendor for gas-liquid mass transfer, typically 2–4 m/s. The MC-99.5 grade is suitable for this reaction provided methanol is below 50 mg/kg, because residual methanol consumes methyl chloride and lowers selectivity to tetramethylammonium chloride. The principal process difference from liquid methylating agents such as dimethyl sulfate is that chloromethane requires pressure equipment and gas-phase feed control, but avoids the bulk liquid toxicity and containment issues associated with strong alkylating agents.
In synthesis of N-methylpyrrolidine and related quaternary ammonium intermediates, chloromethane is charged as a gas into a solvent-free amine melt at 0.3–0.5 MPa. The reaction is conducted in a 316L reactor with a graphite rupture disc rated at 1.1 times the maximum allowable working pressure. The gas feed is stopped when the pressure drop rate falls below 0.5 kPa/min, indicating complete consumption of the amine. This application uses the same MC-99.5 feed specification as silicone monomer production, but the moisture limit is tightened to 30 mg/kg to avoid protonation side reactions and quaternary salt hydrolysis. The use of chloromethane instead of methyl bromide in this reaction changes the operating envelope: methyl bromide is a liquid alkylating agent with a higher reaction rate at lower temperature, while methyl chloride requires elevated pressure and longer feed time under conditions where reaction mass is the limiting rather than the initiator.
Alkali cellulose in a horizontal stirred autoclave of 1.0–6.0 m³ is methylated with chloromethane at 70–100 °C and 0.5–1.0 MPa. The methoxy content is controlled by the molar ratio of chloromethane to anhydroglucose units and by sodium hydroxide content; construction and pharmaceutical grades typically have a methoxy content of 27–32 wt%, corresponding to a degree of substitution of 1.6–2.0. The degree of substitution is measured by gas chromatography after cleavage with hydriodic acid, following the Zeisel method. Chloromethane is preferred over dimethyl sulfate in cellulose ether manufacture because the gaseous feed can be metered directly into the autoclave through a sparge ring and because process safety documentation is simplified by the absence of a liquid highly toxic alkylating agent. The productivity boundary is the lower reactivity of methyl chloride, which requires longer residence time and higher pressure than would be needed with methyl iodide or dimethyl sulfate. The reactor condenser is designed to recover unreacted methyl chloride, and the recovered gas is passed through a caustic scrubber to remove carbon dioxide before recycle.
In synthesis of methyl ethers, methyl thioethers, and N-methyl heterocycles, methyl chloride is selected where methyl bromide is restricted by ozone-depleting substance controls. The substitution changes the rate-limiting reaction profile: methyl chloride is less reactive in SN2 methylation, so conditions shift from 20–40 °C at atmospheric pressure to 70–90 °C and 0.2–0.4 MPa when using the same nucleophile class. This requires a pressure-rated reactor rather than an atmospheric glass vessel. The comparative physical properties in Table 2 define the equipment changes required when switching from liquid chlorinated methanes to chloromethane.
| Property | Chloromethane | Dichloromethane | Chloroform | Carbon tetrachloride |
|---|---|---|---|---|
| Boiling point at 101.3 kPa | -24.2 °C | 39.6 °C | 61.2 °C | 76.7 °C |
| Vapour pressure at 20 °C | 490 kPa | 47 kPa | 21 kPa | 12 kPa |
| Flammability range in air | 8.1–17.4 vol% | Not flammable under normal test conditions | Not flammable under normal test conditions | Not flammable under normal test conditions |
| Water solubility at 25 °C | 5.0 g/L | 13 g/L | 8 g/L | 0.8 g/L |
| Transport classification | UN 1063, Class 2.1 | UN 1593, Class 6.1 | UN 1888, Class 6.1 | UN 1846, Class 6.1 |
Storage and transfer lines for dry methyl chloride are commonly fabricated from carbon steel P235GH, but wet vapour service requires 316L stainless steel or Alloy 20 because hydrolysis produces hydrochloric acid and causes pitting corrosion. The product is incompatible with active metals and strong oxidisers; contact with finely divided aluminium, zinc, magnesium, or sodium must be prevented. High-flow cylinder unloading requires a heated vaporiser to limit auto-refrigeration below -24.2 °C and to avoid liquid carryover into instrumentation. Pressure-relief devices are sized to ISO 4126-1:2013. The harmonised classification under Regulation (EC) No 1272/2008 is Flam. Gas 1 (H220), Press. Gas (H280), Carc. 2 (H351), STOT SE 3 (H335).
