Chloromethyl methyl ether
Chloromethyl methyl ether (CMME), also known as methoxymethyl chloride or MOM chloride, is a synthetic organochlorine compound with the molecular formula C₂H₅ClO and CAS number 107-30-2.[1][2] It appears as a colorless, highly volatile liquid with an irritating odor, a boiling point of 55–59 °C, a flash point of 16 °C (61 °F), and a density of 1.06 g/mL at 25 °C.[2][3] This compound hydrolyzes readily in water to form hydrochloric acid and formaldehyde, making it chemically reactive and unstable in moist environments.[2][3] Primarily utilized as an alkylating agent in organic synthesis, CMME plays a role in manufacturing ion-exchange resins, industrial polymers, and water-repellent coatings.[1] Its production and handling occur in closed systems to limit exposure, given its classification as a Group A known human carcinogen by the U.S. Environmental Protection Agency (EPA), International Agency for Research on Cancer (IARC) Group 1, and National Toxicology Program (NTP).[1][3] Acute exposure via inhalation, skin contact, or ingestion causes severe irritation to the eyes, skin, mucous membranes, and respiratory tract, potentially leading to pulmonary edema, chemical burns, and necrosis.[2][3] Chronic exposure has been linked to respiratory cancers, including lung tumors observed in epidemiological studies of industrial workers and animal models such as mice, rats, and hamsters.[1] Due to its extreme hazards, CMME is subject to stringent regulatory controls, including OSHA's carcinogen standard (29 CFR 1910.1006) with no permissible exposure limit (PEL), a reportable quantity (RQ) of 10 lbs under CERCLA, and inclusion on California's Proposition 65 list as a known carcinogen.[2][3] It is transported under UN 1239 as a toxic liquid (Class 6.1) with a flammable subsidiary risk (Class 3), requiring specialized storage in cool, well-ventilated areas away from ignition sources and moisture.[3] Environmental releases are minimized, though data on persistence or bioaccumulation are limited owing to its rapid hydrolysis.[1]Properties
Physical characteristics
Chloromethyl methyl ether is a colorless liquid at room temperature, often described as clear and oily in appearance.[4][5] Its molecular formula is CH₃OCH₂Cl, with a molecular weight of 80.51 g/mol.[4][6] The compound has a boiling point of 55–59 °C at standard atmospheric pressure (760 mmHg) and a melting point of -104 °C, indicating it remains liquid over a wide temperature range relevant to laboratory and industrial conditions.[4][6] Its density is 1.06 g/cm³ at 25 °C, and the refractive index is 1.396 at 20 °C, aiding in its identification via optical methods.[5][6] The vapor pressure is 192 mmHg at 21 °C, contributing to its volatility and potential for airborne exposure.[4] It exhibits a flash point of -9 to 16 °C (16–61 °F), classifying it as highly flammable.[4][6][2] Regarding solubility, chloromethyl methyl ether hydrolyzes rapidly in water but is miscible with organic solvents such as ethanol, diethyl ether, and chloroform.[7][8]| Property | Value | Conditions |
|---|---|---|
| Molecular formula | CH₃OCH₂Cl | - |
| Molecular weight | 80.51 g/mol | - |
| Appearance | Colorless liquid | Room temperature |
| Boiling point | 55–59 °C | 760 mmHg |
| Melting point | -104 °C | - |
| Density | 1.06 g/cm³ | 25 °C |
| Vapor pressure | 192 mmHg | 21 °C |
| Flash point | -9 to 16 °C (16–61 °F) | - |
| Refractive index | 1.396 | 20 °C (n_D) |
| Solubility | Hydrolyzes in water; miscible with ethanol, ether, chloroform | - |