terabol
Methyl bromide
CAS: 74-83-9
Molecular Formula: CH3Br
terabol - Names and Identifiers
terabol - Physico-chemical Properties
| Molecular Formula | CH3Br |
| Molar Mass | 94.94 |
| Density | 1.7 g/cm3 |
| Melting Point | −94°C(lit.) |
| Boling Point | 4°C(lit.) |
| Flash Point | -34°C |
| Water Solubility | 1.522 g/100 mL |
| Solubility | water: soluble |
| Vapor Presure | 1420 mm Hg ( 20 °C) |
| Vapor Density | 3.3 (20 °C, vs air) |
| Appearance | Colorless gas |
| Exposure Limit | NIOSH REL: IDLH 250 ppm; OSHA PEL: C 20 ppm; ACGIH TLV:TWA 5 ppm. |
| Merck | 13,6056 |
| Storage Condition | 2-8°C |
| Stability | Stable. Incompatible with oxidizing agents, strong acids. This is an ozone-depleting chemical, and its use is restricted in many countries. |
| Explosive Limit | ~16% |
| Refractive Index | 1.4432 |
| Physical and Chemical Properties | Character: colorless gas. Usually odorless. High concentrations have a sweet odor similar to chloroform, with a spicy taste. melting point -93.66 ℃ boiling point 3.56 ℃ relative density 3.974g/L refractive index 1.4432 soluble in ethanol, chloroform, ether, carbon disulfide, carbon tetrachloride, benzene. Liquid methyl bromide can be miscible with alcohol, ether, ketone, etc. |
| Use | Used for grain, wood, warehouse insecticide and tobacco and other soil Disinfection, as pharmaceutical intermediates, fire extinguishing agent |
terabol - Risk and Safety
| Risk Codes | R23/25 - Toxic by inhalation and if swallowed. R36/37/38 - Irritating to eyes, respiratory system and skin. R48/20 - R50 - Very Toxic to aquatic organisms R59 - Dangerous for the ozone layer R68 - Possible risk of irreversible effects R38 - Irritating to the skin R20/22 - Harmful by inhalation and if swallowed. R11 - Highly Flammable R67 - Vapors may cause drowsiness and dizziness R66 - Repeated exposure may cause skin dryness or cracking R19 - May form explosive peroxides R12 - Extremely Flammable R39/23/24/25 - R23/24/25 - Toxic by inhalation, in contact with skin and if swallowed. |
| Safety Description | S15 - Keep away from heat. S27 - Take off immediately all contaminated clothing. S36/39 - 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 the label whenever possible.) S59 - Refer to manufacturer / supplier for information on recovery / recycling. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S36/37 - Wear suitable protective clothing and gloves. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S24 - Avoid contact with skin. S16 - Keep away from sources of ignition. S7 - Keep container tightly closed. |
| UN IDs | UN 1062 2.3 |
| WGK Germany | 3 |
| RTECS | PA4900000 |
| HS Code | 29033990 |
| Hazard Class | 2.3 |
| Toxicity | LC for rats in air (6 hrs): 514 ppm (Irish) |
terabol - Upstream Downstream Industry
| Raw Materials | Methyl alcohol Methyl alcohol Sulfur(α) Bromine |
terabol - Nature
Open Data Verified Data
colorless gas. Usually odorless. High concentrations have a sweet odor similar to chloroform, with a spicy taste. It is not flammable in air, but it can burn in oxygen. Form an explosive mixture with air, and the explosion limit is 13. 5% to 14. 5% (volume). Solubility in water (20 ℃,99. 7kPa)1. 75g/10 og solution. Hydrated crystalline CH3 Br.20H20 was formed below 4 °c. Soluble in ethanol, chloroform, ether, carbon disulfide, carbon tetrachloride, benzene. Liquid methyl bromide can be miscible with alcohol, ether, ketone, etc. Boiling point 3. 56 °c. Melting point 93. 66 °c. Gas density at 20 °c was 3.974g/L. Refractive index (TID 20)1. 4432. Viscosity (O C) 0. 397MPA. s. The critical temperature is 191. The critical pressure is 8. 45MPa. The chemical properties of brominated alkanes are active, and methyl bromide is the most capable of hydrolysis, amination, cyanation, Ester formation and other reactions. And with the increase of bromine atom, the properties tend to be stable.
Last Update：2024-01-02 23:10:35
terabol - Preparation Method
Open Data Verified Data
- by sodium bromide method, methanol and sulfuric acid are added into sodium bromide, and the reaction is carried out by warming up to 60 ℃. The obtained methyl bromide gas is condensed and then deacidified in an alkali washing Tower (5% NaOH), and then sent to a sulfuric acid drying tower for dehydration, the pure product was prepared by distillation.
- hydrobromic acid method is prepared by direct reaction of methanol and hydrobromic acid.
- bromine method the reaction was carried out with sulfur, bromine and methanol in the presence of water.
Last Update：2022-01-01 10:13:48
terabol - Use
Open Data Verified Data
A large number of plant protection for pesticides, fungicides, grain fumigant, can also be used as wood preservatives, refrigerants, low boiling point solvents for organic synthesis, can be prepared by a fluorine methyl chloride; formulated with chloropicrin as a humectant.
Last Update：2022-01-01 10:13:49
terabol - Safety
Open Data Verified Data
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Highly toxic. Rats inhaled LC 514 x 10-6 for 6H. The maximum allowable concentration in the air is 80mg/m3; The workplace is 60mg/m3. Long-term work in an environment above 35 × 10 -6 can cause death. On the human body mainly caused by the spirit of hydroxyl system disorders, pulmonary edema, renal atresia. The incubation period of several hours, the beginning of a headache, discomfort, and then appear behavior disorders, blurred vision, and even epilepsy and spasm.
- in order to prevent poisoning, the workplace is required to be well ventilated and wear leather labor protection articles. Prevention of methyl bromide and aluminum products contact (aluminum and methyl bromide contact can spontaneous combustion). The operator should often blood test, when the amount of bromine in blood reaches 5 mg/mL, that should be paid attention.
- packaging should be marked with "drug" sign, so that methyl bromide is dissolved in excess solvent and stored in a dark place. The use of rubber products and aluminum packaging is strictly prohibited.
Last Update：2022-01-01 10:13:50
terabol - Reference Information
| Henry's Law Constant | 0.72 at 21 °C (Gan and Yates, 1996) |
| (IARC) carcinogen classification | 3 (Vol. 41, Sup 7, 71) 1999 |
| NIST chemical information | information provided by: webbook.nist.gov (external link) |
| EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
| fumigation insecticide | methyl bromide is a bromoalkane fumigation insecticide with bactericidal, nematicidal and rodenticidal effects. At room temperature is a gas, compressed into liquid in the cylinder, when used to open the cylinder valve, you can automatically spray out and spread to the warehouse or fumigation room. The density of the gas 3.27, boiling point of 3.6 deg C, the vapor pressure of 20 deg C 186 650 Pa, the general use of no combustion risk concentration. Very strong permeability is a low-temperature fumigant. Oral LD50 214mg/kg, acute inhalation toxicity LC50 was 3 120 mg/L(15 min), human inhalation toxicity LC50 was 6 000 mg/L(2 h). No carcinogenic effect in the test conditions, insecticidal broad-spectrum, used for the control of stored grain pests on rice, Valley, Valley, red mud, wheat moth, Indian Valley moth, Bean, Millet bark, corn has a good control effect, the dosage of 27~37.5g/m3, the moisture content of seed and grain fumigation must be controlled below 12%. methyl bromide, also known as methyl bromide and methyl bromide, is more chemically active than bromoethane and can carry out many reactions (see "bromoethane"). Formula CH3Br. Colorless transparent volatile, sweet liquid. Molecular weight 94.95, specific gravity 1.6755 (20/4 ℃), boiling point 4.6 ℃. Slightly soluble in water, soluble in alcohol, ether, chloroform, carbon disulfide, carbon tetrachloride, carbon disulfide, ether, benzene and other organic solvents. Slightly soluble in water. Highly toxic! The explosive mixture is formed with air, the explosion limit is 13.5% ~ 14.5% (volume fraction), and the maximum allowable concentration in air is 5 mg/kg. Used as fumigant, methylating agent and fire extinguishing agent in automatic fire extinguishing system of aircraft engine. Inhalation is a moderate toxin. Neurotoxicant. Mouse LC50 is 1540mg/m3. Can enter the body through the respiratory tract, digestive tract and skin. Irritation of the eye and upper respiratory tract can occur when exposed to vapors. Skin contact showed simple blisters. After several hours to several days of incubation period, there was obvious dizziness, Head Pain, Fatigue, loss of appetite, Nausea, Vomit, Cough, chest tightness, Dyspnea, etc. Severe cases also present with delirium, convulsions, status epilepticus, cerebellar ataxia, Mental Disorder, Coma, pulmonary edema, renal failure, or Shock. Inhalation of high concentrations can be in a few minutes due to respiratory depression and sudden death. The patient was immediately separated from the site and changed contaminated clothing. People with skin pollution can wash with soap and water. Inhalation of this product should be closely observed 24h ~ 48H. Acute poisoning mainly in the prevention and treatment of pulmonary edema and cerebral edema. Symptomatic treatment. Industrial production should pay attention to closed, strict implementation of safe operation. Skin contact is prohibited. The maximum allowable concentration in the air of the workshop is 1mg/m3. |
| method of use | hermetic fumigation was used to control storage pests and rats. Soil fumigation can control plant diseases such as bacterial wilt, bacterial wilt, silk disease and root nodule nematode. 18~45g/m 3 fumigation 24 hours can prevent storage of rice, wheat, beans and other raw grains and flour, feed, nuts, dried fruits, such as rice, Valley, Valley, red mud, wheat moth, Indian Valley Borer, Bean elephant, grain spot bark, corn elephant, acaroid mites and other pests; Water content of more than 12% of the seeds can not be fumigated, in order to prevent the impact of germination. 32~50g/m 3 fumigation for 2~4 hours, can control fresh vegetables, fruit of corn borer, Bean borer and other Lepidoptera larvae, turtle, fruit flies, scale insects, spider mites, Diptera and so on. 16~50g/m 3 fumigation of greenhouse plants, can control the scale worm, thrips, aphids, spider mites, white flies, leaf flies, mosquito and other pests and some of the boring pests. 30~45g/m 3 fumigation 24~36 hours, can control cotton, wool and Wood Moth. 4~6g/m 3 fumigation 4~5 hours can be rodent. High temperature, strong fumigation, dosage should be reduced accordingly. Some live, fresh plants, fruits are more sensitive, should be done before the use of small area test, to prevent damage. Because of the high toxicity of methyl bromide, no special antidote, use should pay attention to safety. |
| preparation method | 1, red phosphorus is decomposed into methanol, and then bromine is added, which can be obtained. 2, with methanol as raw material, in the presence of sulfur dioxide and water, and bromine reaction, can be obtained. Chemical reaction equation: 2CH3OH Br2 SO2 H2O → 2CH3Br 2H2SO4 3, using methanol as raw material, sulfur is dispersed into water first, then methanol is added, and then bromine is added. Chemical reaction equation: 6CH3OH 3Br2 S H2O → 6CH3Br H2SO4 3H2O 4, with methyl chloride as raw material, in the presence of high temperature and aluminum bromide, and hydrobromic acid reaction can be prepared. 5 it can be obtained by reacting methanol with sodium bromide in the presence of sulfuric acid at 60 ° C., and then separated by distillation. Chemical reaction equation: 2CH3OH 2NaBr H2SO4 → 2CH3Br Na2SO4 2H2O 6, direct bromination of methane, can be prepared. 7, it can be obtained by photochemical reaction of methane and bromine chloride. 8, methyl chloride in acetone solution with sodium bromide reflux, can be prepared. |
| Use | pesticides, fungicides, grain fumigants, wood preservatives, refrigerants, low boiling point solvents, etc, it is also used in organic synthesis methyl bromide is an intermediate of the herbicides tribenuron and profezin, and can also be used as a methyl ring oxidant to produce tebuconazole, hexaconazole, etc., and can be used as a fumigant. The product is a fumigant, can be insecticidal, mice and some bacteria. This product has a low boiling point, can directly open the cylinder valve, so that the gas is automatically ejected. When the temperature is above 25 ℃, the dosage is usually 0.0027-0.00375kg/m3 space, and the capsule is fumigated for 2-3 days. It can also be used as a wood preservative, refrigerant, low boiling point solvent, used in organic synthesis, and can be used to prepare a fluorine methyl chloride; And chloropicrin is formulated as a moisturizing agent. used as grain, wood, warehouse insecticide and tobacco soil Disinfection, as pharmaceutical intermediates, fire extinguishing agent |
| production method | the production methods of methyl bromide are sodium bromide method, hydrobromic acid method and bromine method. Sodium bromide method and hydrobromic acid method because of the high consumption of raw materials, sources of difficulty, to use sulfuric acid in production, serious corrosion of equipment, therefore, has not been used abroad. The bromine method is the main method for the production of methyl bromide with high yield, simple process and less capital investment. (1) bromine method sulfur bromide is prepared by mixing bromine and sulfur, and then sulfur bromide is added dropwise into methanol to react at 50-65 ℃, and the reactants are continuously distilled to obtain methyl bromide, the methyl bromide gas generated by the reaction is washed with 5% caustic soda solution, and then passed into the pickling tower to wash with sulfuric acid, then dried with anhydrous calcium chloride in the drying tower, and finally compressed and liquefied to obtain product methyl bromide. The purity can reach more than 98%. Each ton of product consumption of bromine 887kg, methanol 374kg, sulfur 90kg, sodium hydroxide 15kg. (2) the hydrobromic acid method is obtained by reacting methyl chloride with hydrobromic acid in the presence of aluminum bromide, and the yield is 90%. (3) the sodium bromide method uses methanol, sodium bromide and sulfuric acid as raw materials, and the reaction is obtained: The process is as follows: sodium bromide is added to the lead-lined or enamel reaction pot, and sulfuric acid and methanol are pressed into the pipe, steam heating from the jacket, when the reaction temperature rises to 60 degrees Celsius, that is, the appropriate control of the reaction rate, methyl bromide gas from the reaction pot, after the copper condenser cooling into alkaline water (5% NaOH) the acid is removed from the washing Tower, and then the water is removed from the sulfuric acid drying tower. The product is compressed to 0.98MPa. Raw material consumption quota: sodium bromide 1100kg/t, methanol 40kg/t, sulfuric acid 1960kg/t. Purposes: the product as a fumigant, insecticidal, rats and some bacteria. This product has a low boiling point, can directly open the cylinder valve, so that the gas is automatically ejected. When the temperature is above 25 ℃, the dosage is usually 0.0027-0.00375kg/m3 space, and the capsule is fumigated for 2-3 days. It can also be used as a wood preservative, refrigerant, low boiling point solvent, used in organic synthesis, and can be used to prepare a fluorine methyl chloride; And chloropicrin is formulated as a moisturizing agent. There are two production processes for its preparation. (1) sodium bromide method in the reaction kettle to add sodium bromide and sulfuric acid methanol, jacket steam heating, when the reaction temperature is 60 degrees Celsius to control the reaction rate, Methyl bromide is distilled out, acid is removed by alkaline water (5% NaOH) washing Tower, dried and dehydrated by drying tower, and the finished product is obtained by compression. CH3OH + NaBr + H2SO4 → CH3Br + NaHSO4 + H2O(2) bromine method sulfur, methanol and bromine in the reaction kettle reaction temperature 45~100 ℃ is better. 4CH3OH+Br2+S→4CH3Br+SO2+2H2O |
| category | hazardous gas |
| toxicity grade | high toxicity |
| Acute toxicity | inhalation-rat LC50: 302 PPM/ 8 hours; Oral-rat LD50: 214 mg/kg |
| explosive hazard characteristics | the steel cylinder can be exploded by heating and sun exposure; The leakage releases highly toxic smoke; mixture with air can be exploded |
| flammability hazard characteristics | flammable when exposed to high temperature, open flame and aluminum powder; toxic bromide smoke from combustion |
| storage and transportation characteristics | The warehouse is ventilated and dried at low temperature; separate from combustion-supporting gas |
| fire extinguishing agent | water, foam, carbon dioxide mist |
| Occupational Standard | TWA 20 mg/m3; Tel 97 mg/m3 |
| DOT Classification | 2.3, Hazard Zone C (Gas poisonous by inhalation) |
| toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |
| immediate life-and health-threatening concentration | 250 ppm |
Last Update：2024-04-09 02:00:11
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