| Identification | More | [Name]
Iodomethane | [CAS]
74-88-4 | [Synonyms]
IODOMETHANE
METHYL IODIDE
10domethane
CH3I
Halon 10001
halon10001
Iodmethan
Iodometano
iodo-methan
Iodure de methyle
ioduredemethyle
ioduredemethyle(french)
Jodmethan
Jod-methan
Joodmethaan
Methane, iodo-
Methane,iodo-
Methyl iodine
Methyliodid
Methyliodide(CH3I) | [EINECS(EC#)]
200-819-5 | [Molecular Formula]
CH3I | [MDL Number]
MFCD00001073 | [Molecular Weight]
141.94 | [MOL File]
74-88-4.mol |
| Chemical Properties | Back Directory | [Appearance]
Methyl iodide is a colorless liquid. Pungent,
ethereal odor. Turns yellow, red, or brown on exposure to
light and moisture. | [Melting point ]
−64(lit.)
| [Boiling point ]
41-43 °C
| [density ]
2.28 g/mL at 25 °C(lit.)
| [vapor density ]
4.89 (vs air)
| [vapor pressure ]
24.09 psi ( 55 °C)
| [refractive index ]
n20/D 1.530
| [Fp ]
−18 °F
| [storage temp. ]
Store at 0°C | [solubility ]
water: soluble14g/L at 20°C | [form ]
Liquid | [color ]
Clear | [Specific Gravity]
2.280 | [Odor]
Sweet, ethereal odor (no threshold data available); inadequate warning properties | [PH]
5.2 (H2O, 25℃) | [Water Solubility ]
14 g/L (20 ºC) | [Sensitive ]
Light Sensitive | [Merck ]
14,6087 | [BRN ]
969135 | [Henry's Law Constant]
5.06 at 21 °C (Gan and Yates, 1996) | [Dielectric constant]
7.0（20℃） | [Exposure limits]
TLV-TWA 2 ppm (～11 mg/m3) (ACGIH),
5 ppm (MSHA and OSHA); carcinogenicity:
Animal Limited Evidence (IARC), Suspected
Human Carcinogen. | [Stability:]
Light Sensitive | [LogP]
1.510 | [CAS DataBase Reference]
74-88-4(CAS DataBase Reference) | [IARC]
3 (Vol. 41, Sup 7, 71) 1999 | [NIST Chemistry Reference]
Methyl iodide(74-88-4) | [EPA Substance Registry System]
74-88-4(EPA Substance) |
| Safety Data | Back Directory | [Hazard Codes ]
T,F,Xn | [Risk Statements ]
R21:Harmful in contact with skin.
R23/25:Toxic by inhalation and if swallowed .
R37/38:Irritating to respiratory system and skin .
R40:Limited evidence of a carcinogenic effect.
R11:Highly Flammable.
R39/23/24/25:Toxic: danger of very serious irreversible effects through inhalation, in contact with skin and if swallowed .
R23/24/25:Toxic by inhalation, in contact with skin and if swallowed .
R38:Irritating to the skin.
R20/22:Harmful by inhalation and if swallowed . | [Safety Statements ]
S36/37:Wear suitable protective clothing and gloves .
S38:In case of insufficient ventilation, wear suitable respiratory equipment .
S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) .
S9:Keep container in a well-ventilated place .
S24:Avoid contact with skin .
S16:Keep away from sources of ignition-No smoking . | [RIDADR ]
UN 2644 6.1/PG 1
| [WGK Germany ]
1
| [RTECS ]
PA9450000
| [F ]
8 | [TSCA ]
Yes | [HazardClass ]
6.1 | [PackingGroup ]
I | [HS Code ]
29033990 | [Safety Profile]
Confirmed carcinogen
with experimental neoplastigenic and
tumorigenic data. A poison by ingestion,
intraperitoneal, and subcutaneous routes.
Moderately toxic by inhalation and skin
contact. A human skin irritant. Human
mutation data reported. A strong narcotic
and anesthetic. Explosive reaction with trialkylphosphines, silver chlorite. Violent
reaction with oxygen (at 3000C), sodium.
When heated to decomposition it emits
toxic fumes of I-. | [Hazardous Substances Data]
74-88-4(Hazardous Substances Data) | [Toxicity]
LD50 orally in rats: 76 mg/kg; LD50 s.c. in mice: 0.78 mmoles/kg (IARC, 1986) | [IDLA]
100 ppm |
| Raw materials And Preparation Products | Back Directory | [Raw materials]
Calcium carbonate-->Calcium chloride-->Potassium iodide-->Phosphorus | [Preparation Products]
2-IODO-3-METHOXY-6-METHYLPYRIDINE-->2-METHOXY-5-NITROBENZALDEHYDE-->Prazosin-->4-METHYL-2-(METHYLSULFANYL)PYRIMIDINE-->5-METHOXY-2-METHYLPYRIDINE-->2,2-DIMETHYLCYCLOPENTANONE-->Clarithromycin-->3,5-DIMETHYL-3H-IMIDAZOLE-4-CARBOXYLIC ACID ETHYL ESTER-->4(3H)-Pyrimidinone, 5-methyl-2-(methylthio)--->5-BROMO-4-CHLORO-2-METHYLSULFANYL-PYRIMIDINE-->GRANISETRON-D3-->BENZYL-(2-METHYLSULFANYL-PYRIMIDIN-4-YL)-AMINE-->(S)-(+)-Methyl glycidyl ether-->4-Chloro-2-methylthiopyrimidine-->2-Bromo-3-methoxy-6-methylpyridine-->Fluorocaruor surfactant FC-4-->4-CHLORO-N-METHYLPYRIMIDIN-2-AMINE-->(1-METHYL-1H-BENZIMIDAZOL-2-YL)METHYLAMINE-->2,2-DIMETHYLCYCLOHEXANONE-->Astemizole-->3-Methyl-4-nitroanisole-->(R)-(-)-Methyl glycidyl ether-->4,6-Dimethyl-2-methylmercapyrimidine-->7-Methoxycoumarin-->3,3-DIMETHYLISOBENZOFURAN-1(3H)-ONE-->Neopentyl iodide-->fluorocarbon sulfactant FC-3-->1-[2-(Dimethylamino)ethyl]-1H-tetrazole-5-thiol-->3,17-Dihydroxyandrost-5-ene-17-propionic acid phtassium salt-->Canrenone-->2-PHENYL-2-PROPANOL-->Androst-5-ene-3,17-diol-17-propanoic acid lactone-->Methandriol-->3-oxopregn-4-ene-21,17alpha-carbolactone-->5-Mercapto-1H-tetrazole-1-methane sulphonic acid-->2-Acetyl-3-methylpyrazine-->3,17-Dihydroxyandrost-5-ene-17-propiolic acid-->1 2-DIMETHYLPYRIDINIUM IODIDE 97-->Androst-5-ene-3,17-diol-17-propiolic acid potassium salt-->Benzyltrimethylammonium iodide |
| Hazard Information | Back Directory | [General Description]
A colorless liquid that turns brown on exposure to light. Denser than water. Contact may irritate skin, eyes and mucous membranes. Very toxic by ingestion, inhalation and skin absorption. | [Reactivity Profile]
Halogenated aliphatic compounds, such as METHYL IODIDE(74-88-4), are moderately or very reactive. Reactivity generally decreases with increased degree of substitution of halogen for hydrogen atoms. Low molecular weight haloalkanes are highly flammable and can react with some metals to form dangerous products. Materials in this group are incompatible with strong oxidizing and reducing agents. Also, they are incompatible with many amines, alkylphosphines, nitrides, azo/diazo compounds, alkali metals (sodium), and epoxides. | [Air & Water Reactions]
Soluble in water. Sinks and slowly decomposes in water forming poisonous vapor cloud of HI. | [Hazard]
Toxic by ingestion, inhalation, and skinabsorption; narcotic, irritant to skin. Eye damageand central nervous system impairment. Question-able carcinogen. | [Health Hazard]
Inhalation of vapor causes lung congestion and pulmonary edema. Higher concentrations causes rapid narcosis and death. Contact with liquid irritates eyes and burns skin. | [Potential Exposure]
Methyl iodide is used in fire
extinguishers; as an intermediate in the manufacture of
pharmaceuticals and some pesticides. | [First aid]
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Seek medical attention immediately.
If this chemical has been inhaled, remove from exposure,
begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if
heart action has stopped. Transfer promptly to a medical
facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce
vomiting. Do not make an unconscious person vomit.
Medical observation is recommended for 24 to 48 hours
after breathing overexposure, as pulmonary edema may be
delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consider administering a drug or
other inhalation therapy. | [Shipping]
UN2644 Methyl iodide, Hazard Class: 6.1;
Labels: 6.1-Poison Inhalation Hazard, Inhalation Hazard
Zone B | [Incompatibilities]
May form explosive mixture with air.
Slowly reacts with water forming poisonous hydrogen
iodide. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep
away from alkaline materials, strong bases, strong acids,
oxoacids, epoxides. Violent reaction with strong oxidizers,
strong reducing agents, strong bases; trialkylphosphines,
silver chlorite; calcium, oxygen, sodium. Decomposes @
270C. Halogenated aliphatic compounds are moderately or
very reactive. Halogenated organics generally become less
reactive as more of their hydrogen atoms are replaced with
halogen atoms. Low molecular weight haloalkanes are
highly flammable and can react with some metals to form
dangerous products. Materials in this group are incompatible with strong oxidizing and reducing agents. Also, they
are incompatible with many amines, alkylphosphines,
nitrides, azo/diazo compounds, alkali metals (sodium), and
epoxides | [Description]
Methyl iodide is a colorless liquid with a pungent, ether-like odor. Turns yellow, red, or brown on exposureto light and moisture. Molecular weight = 141.94; Specificgravity (H2O:1) 5 2.28; Boiling point = 42.8℃; Vaporpressure 5 400 mmHg; Freezing/Melting point 5 2 66.7℃.It is noncombustible. Hazard Identification (based on NFPA704 M Rating System): Health 2, Flammability 1, Reactivity0. Slightly soluble in water; solubility 5 1%. | [Chemical Properties]
light yellow to light pink liquid | [Chemical Properties]
Methyl iodide is a colorless liquid. Pungent,
ethereal odor. Turns yellow, red, or brown on exposure to
light and moisture. | [Waste Disposal]
Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform to EPA regulations governing storage, transportation, treatment, and
waste disposal | [Physical properties]
Clear, colorless liquid which may become yellow, red, or brown on exposure to light and moisture | [Uses]
.Iodomethane is an approved pesticide used to control insects, plant parasitic nematodes, soil borne pathogens and weed seeds. | [Uses]
Methyl iodide is used in the analysis of pyridine; microscopy; as an embedding materialfor examining diatoms (Merck 1996); and asa methylating agent. | [Uses]
Methylating agent; in microscopy because of its high refractive index; as imbedding material for examining diatoms; in testing for pyridine. Light sensitive etching agent for electronic circuits; component in fire extinguishers. | [Definition]
(methyl
iodide; CH3I) A liquid alkyl halide made
by reaction of methanol with iodine in the
presence of red phosphorus. | [Definition]
ChEBI: A member of the class of iodomethanes that is methane in which one of the hydrogens is replaced by iodine. | [Production Methods]
Methyl iodide has had very limited use as a chemical
intermediate (methylations), and in microscopy because of
its high refractive index, as imbedding materials for examining
diatoms, and in tests for pyridine. It has been proposed
as a fire extinguisher and insecticidal fumigant. It is a product
of natural biological processes. Methyl iodide is a currently
registered pesticide. | [Fire Hazard]
Noncombustible. High vapor pressure may cause containers to burst at elevated
temperatures. | [Flammability and Explosibility]
Noncombustible. High vapor pressure may cause containers to burst at elevated
temperatures. | [Carcinogenicity]
Druckrey et al. reported
local sarcomas following weekly subcutaneous injection in
BD strain rats. Strain A mice (a susceptible strain) that were
injected with methyl iodide were reported to have a slight but
significant increase in the number of lung tumors per mouse.
Poirer et al. administered iodomethane dissolved in
tricaprylin to male and female strain A mice (10/sex/dose)
three times weekly by intraperitoneal injection. There was a
marginally statistically significant trend for increased lung
tumors in treated mice but the outcome was considered
equivocal: no clear dose–response relationship and occurrence
of spontaneous tumors in untreated mice.
Under the 2005 Guidelines for Carcinogen Risk Assessment
(121), the lack of available evidence suggests that there
is “inadequate information to assess the carcinogenic potential
for iodomethane.”
An early evaluation by the IARC classified
iodomethane as carcinogenic in rats. Two subsequent evaluations
(123, 124) determined that there is limited evidence
for carcinogenicity in experimental animals and the compound
is not classifiable regarding carcinogenicity to
humans. ACGIH has also reviewed iodomethane
carcinogenicity and classified it as category A2, suspected
human carcinogen; however, the A2 classification was withdrawn
in 1996. Iodomethane was delisted as a carcinogen
in the NTP 5th Annual Report on Carcinogens on the
basis of the 1986 IARC reevaluation. NTP
has not tested iodomethane for carcinogenicity. The State of
California determined under Proposition 65 that methyl
iodide is a carcinogen, based on the 1977 IARC evaluation. Neither a Toxicological Profile nor an
Environmental Health Criteria Monograph has been
published. | [Environmental Fate]
Chemical/Physical. Anticipated products from the reaction of methyl iodide with ozone or OH
radicals in the atmosphere are formaldehyde, iodoformaldehyde, carbon monoxide, and iodine
radicals (Cupitt, 1980). With OH radicals, CH2, methyl radical, HOI and water are possible
reaction products (Brown et al., 1990). The estimated half-life of methyl iodide in the atmosphere,
based on a measured rate constant for the vapor phase reaction with OH radicals, ranges from 535
h to 32 wk (Garraway and Donovan, 1979).
Hydrolyzes in water forming methyl alcohol and hydriodic acid. The estimated half-life in water
at 25 °C and pH 7 is 110 d (Mabey and Mill, 1978). At 70 °C, the hydrolysis rate was determined
to be 3.2 x 10-5/sec which is equivalent to a half-life of 6 h. (Glows and Wren, 2003). May react
with chlorides in seawater to form methyl chloride (Zafiriou, 1975). | [storage]
Color Code—Blue: Health Hazard/Poison: Storein a secure poison location. Prior to working with thischemical you should be trained on its proper handling andstorage. Store in tightly closed containers in a cool, wellventilated area away from oxidizers. Where possible, automatically pump liquid from drums or other storage containers to process containers. A regulated, marked area shouldbe established where this chemical is handled, used, orstored in compliance with OSHA Standard 1910.1045. | [Purification Methods]
Methyl iodide deteriorates rapidly with liberation of iodine if exposed to light. It is usually purified by shaking with dilute aqueous Na2S2O3 or NaHSO3 until colourless, then washing with water, dilute aqueous Na2CO3, and more water, drying with CaCl2 and distilling. It is stored in a brown bottle away from sunlight in contact with a small amount of mercury, powdered silver or copper. (Prolonged exposure of mercury to methyl iodide forms methylmercuric iodide.) Methyl iodide can be dried further using CaSO4 or P2O5. An alternative purification is by percolation through a column of silica gel or activated alumina, then distillation. The solution can be degassed by using a repeated freeze-pump-thaw cycle. [Beilstein 1 IV 87.] |
| Questions And Answer | Back Directory | [Overview]
Iodomethane is also commonly called methyl iodide. It is a volatile liquid related to methane by replacement of hydrogen. Iodomethane is miscible with common organic solvents. It is colourless, although upon exposure to light, samples develop a purplish tinge. Iodomethane (methyl iodide) is widely used in organic synthesis to deliver a methyl group, via the transformation called methylation.[1]
Iodomethane(also known as methyl iodide), is a kind of alkyl halide. It is naturally emitted by rice plantations in small amounts. Algae are a great natural producer of it with annual output of being greater than 214,000 tons. Therefore, it exists in ocean in large amount. Terrestrial fungi and bacteria also produce certain amount of iodomethane[2, 3]. It is used in organic synthesis as a source of methyl groups.
Methyl iodide had been approved for use as a pesticide by the United States Environmental Protection Agency in 2007 as a pre-plant biocide used to control insects, plant parasitic nematodes, soil borne pathogens, and weed seeds in vegetables such as. It was registered for use as a pre-plant soil treatment for field grown strawberries, peppers, nut crops, tomatoes, grape vines, ornamentals and turf and nursery grown strawberries, stone fruits, tree nuts, and conifer trees. After the discovery phase in a consumer lawsuit, the manufacturer withdrew the fumigant citing its lack of market viability[4].
| [Physicochemical properties]
Iodomethane, an alkyl halide, is a colorless to pale yellow liquid with an acrid odor. It is stable at room temperature in sealed containers, non-corrosive to metals, and incompatible with strong oxidizing and reducing agents. On exposure to light and moisture, the color turns yellow, red or brown due to decomposition and the liberation of free iodine. When heated to decomposition in air at 270 degree, toxic iodine vapors are emitted. Iodomethane is soluble in water, and is miscible with alcohol and ether[5-7].
| [Synthesis]
Iodomethane can be synthesized by the following several methods[8]:
I. The reaction between methanol with phosphorus triiodide
II. The reaction of dimethyl sulfate with potassium iodide in the presence of calcium carbonate
III. The reaction of methanol with aqueous hydrogen iodide.
IV. The reaction of iodoform with potassium hydroxide and dimethyl sulfate in the presence of ethanol.
| [Application]
Iodomethane is a useful methylating agent that mediates the alkylation of carbon, oxygen, sulfur, nitrogen and phosphorus nucleophiles[9, 10]. For example, phenol reacts with methyl iodide to give anisole. In the Monsanto process, the in situ formed iodomethane reacts with carbon monoxide in the presence of a rhodium complex to give acetyl iodide, which on hydrolysis yields acetic acid[11]. It reacts with magnesium to form the Grignard reagent, methyl-magnesium iodide used in organic synthesis[12]. It also finds applications as an intermediate in the manufacture of pharmaceuticals and in phase-transfer catalysts.
Methyl iodide can also be used as a kind of pesticide used to control insects, plant parasitic nematodes, soil borne pathogens, and weed seeds in vegetables. It can be used in the field growing strawberries, peppers, nut crops, tomatoes, grape vines, ornamentals and turf and nursery growing strawberries, stone fruits, tree nuts, and conifer trees. Its fumigant action is thought to be via the nucleophilic displacement(SN2) reaction in various amino acids and peptides within target organisms. It can also be used as a fire extinguisher[4, 5, 13, 14].
| [Regulation]
Methyl bromide is scheduled for elimination as a soil fumigant and iodomethane has been proposed as an alternative[15-18]. Based on the atmospheric lifetime, global warming potential, and ozone depletion potential, the U.S. Environmental Protection Agency(USEPA) has identified iodomethane as a reduced risk alternative to methyl bromide.
In October, 2007, the USEPA issued a one year time-limited registration of iodomethane. In April 2009, USEPA extended conditional registration of iodomethate without specifying any time limits. The USEPA website provides details of the registration[19]. An application for California registration is currently being evaluated by DPR. Due to its acute toxicity, proposed products containing iodomethane are labeled as restricted use pesticides.
| [Warning and toxicity]
Iodomethane may have certain toxicity when exposure to human and animals[20-22]. In humans, acute[short-term] exposure when inhaling iodomethane may depress the central nervous system(CNS), irritate the lungs and skin, and affect the kidneys[20]. Massive acute inhalation exposure to methyl iodide has led to pulmonary edema. Acute inhalation exposure of humans to methyl iodide has resulted in nausea, vomiting, vertigo, ataxia, slurred speech, drowsiness, skin blistering, and eye irritation[20, 21]. Chronic(long-term) exposure of humans to methyl iodide by inhalation may affect the CNS and cause skin burns in animals and humans. EPA has not classified methyl iodide for potential carcinogenicity[20-22].
| [References]
- K. R. Redeker; N.-Y. Wang; J. C. Low; A. McMillan; S. C. Tyler & R. J. Cicerone[2000]. "Emissions of Methyl Halides and Methane from Rice Paddies". Science. 290[5493]: 966–969. doi:10.1126/science.290.5493.966.
- https://www.sfgate.com/green/article/Methyl-iodide-gains-state-OK-for-use-on-crops-2455128.php
- https://www.mercurynews.com/2012/03/20/maker-of-methyl-iodide-scraps-controversial-pesticide/ https://sitem.herts.ac.uk/aeru/ppdb/en/Reports/1233.htm
- Keigwin, Richard P. "Iodomethane; Notice of Receipt of Request to Voluntarily Cancel Iodomethane Pesticide Registrations and Amend a Registration." Federal Register[2012].
- DPR. 2002a. Product chemistry #1. Volume No. 52875-4, Department of Pesticide Regulation, Registration Branch, Sacramento, California.
- Meister, R.T., ed. 2004. Crop protection handbook. Meister Publishing Company, Willoughby.
- O’Neil, M.J. 2001. The Merck index, 13th ed. Merck & Co., Whitehouse Station, New Jersey.
- http://www.orgsyn.org/demo.aspx?prep=CV2P0399
- Sulikowski, Gary A., and M. M. Sulikowski. Iodomethane. e-EROS Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons, Ltd, 2005.
- Erk, B.; Boll, R., Trippel, S.; Anielski, D.; Foucar, L.; Rudek, B.; Rudenko, A. Imaging charge transfer in iodomethane upon x-ray photoabsorption. Science 2014, 345[6194], 288-291.
- Dong, Y.; Brooks, J. D.; Chen, T. L.; Mullins, D. R.; Cox, D. F. Reactions of methyl groups on a non-reducible metal oxide: The reaction of iodomethane on stoichiometric alpha-Cr 2 O 3[0001]. Surf. Sci. 2015, 641, 148-153.
- Bodewitz, H. W. J. J., et al. "The formation of grignard compounds—V: The reaction of iodomethane with magnesium in allyl phenyl ether. A second-order cidnp spectrum." Tetrahedron 34.16(1978]: 2523-2527.
- https://sitem.herts.ac.uk/aeru/ppdb/en/Reports/1233.htm
- G.D. Clayton and F.E. Clayton, Eds. Patty's Industrial Hygiene and Toxicology. Volume IIB. 3rd revised ed. John Wiley & Sons, New York. 1981.
- Ohr, H.D., J.J. Sims, N.M. Grech, J.O. Becker, and M.E. Mcgriffen. 1996. Methyl iodide, an ozone-safe alternative to methyl bromide as a soil fumigant. Plant Dis. 80(7]: 731-735.
- Sims, J.J., N.M. Grech, J.O. Becker, M.E. McGiffen, and H.D. Ohr. 1995. Methyl iodide: a potential alternative to methyl bromide. Page 46 in Proc. Of the Second Annual Int. Res. Conf. On Methyl Bromide Alternatives and Emissions Reductions, San Diego. 6-8 Nov. 1995. Methyl Bromide Alternative Outreach, Fresno, CA.
- U.S. Environmental Protection Agency. 1993. Protection of stratospheric ozone. RED. Reg. 58(51]:15014-15049.
- The United Nations Environmental Programmes. 1995. The Montreal protocol on substances that deplete the ozone layer. 1994 Report of the Methyl Bromide Technical Option Committee. UNEP, Nairobi, Kenya.
- http://www.epa.gov/pesticides/factsheets/iodomethane_fs.htm
- M. Sittig. Handbook of Toxic and Hazardous Chemicals and Carcinogens. 2nd ed. Noyes Publications, Park Ridge, NJ. 1985.
- The Merck Index. An Encyclopedia of Chemicals, Drugs, and Biologicals. 11th ed. Ed. S. Budavari. Merck and Co. Inc., Rahway, NJ. 1989.
- https://www.epa.gov/sites/production/files/2016-09/documents/methyl-iodide.pdf
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