Methyl isocyanate (C2H3NO) is a volatile chemical used in the production of various materials. It is known for its toxic nature and potential risks to human health and the environment.
| IUPAC Name | Methyl Isocyanate |
| Molecular Formula | C2H3NO |
| CAS Number | 624-83-9 |
| Synonyms | Isocyanatomethane, MIC, Methyl carbimide, Methyl carbylamine |
| InChI | InChI=1S/C2H3NO/c1-2-4-3/h1H3 |
Methyl Isocyanate Properties
Methyl Isocyanate Formula
The formula of methyl isocyanate (MIC) is C2H3NO. It consists of two carbon atoms (C), three hydrogen atoms (H), one nitrogen atom (N), and one oxygen atom (O). This chemical formula represents the composition of methyl isocyanate at the molecular level.
Methyl Isocyanate Molar Mass
The molar mass of MIC is calculated by adding up the atomic masses of its constituent elements. With two carbon atoms, three hydrogen atoms, one nitrogen atom, and one oxygen atom, the molar mass of MIC is approximately 57.05 grams per mole.
Methyl Isocyanate Boiling Point
MIC has a relatively low boiling point. At standard atmospheric pressure, it boils at around 39 degrees Celsius (102 degrees Fahrenheit). This means that at temperatures above its boiling point, MIC will transition from a liquid to a gaseous state.
Methyl Isocyanate Melting Point
The melting point of MIC is lower than its boiling point. It solidifies at temperatures around -47 degrees Celsius (-53 degrees Fahrenheit). This means that when exposed to temperatures below its melting point, MIC will transition from a liquid to a solid state.
Methyl Isocyanate Density g/mL
The density of MIC is an indicator of its mass per unit volume. It has a density of approximately 0.97 grams per milliliter (g/mL) at room temperature and pressure. This density value provides information about the compactness of MIC molecules in a given volume.
Methyl Isocyanate Molecular Weight
The molecular weight of MIC is the sum of the atomic weights of its constituent elements. With carbon having a molecular weight of approximately 12.01 grams per mole, hydrogen around 1.01 grams per mole, nitrogen around 14.01 grams per mole, and oxygen roughly 16.00 grams per mole, the molecular weight of MIC is around 57.05 grams per mole.
Methyl Isocyanate Structure
The structure of MIC consists of a methyl group (-CH3) bonded to an isocyanate functional group (-NCO). This arrangement forms a linear molecule with the carbon atom bonded to the nitrogen atom and the oxygen atom.
Methyl Isocyanate Solubility
MIC exhibits limited solubility in water. It is considered moderately soluble, with an approximate solubility of 6 grams per 100 milliliters of water at room temperature. However, it is highly soluble in organic solvents such as acetone, chloroform, and toluene.
| Appearance | Colorless liquid |
| Specific Gravity | 0.97 g/mL |
| Color | Colorless |
| Odor | Pungent |
| Molar Mass | 57.05 g/mol |
| Density | 0.97 g/mL |
| Melting Point | -47 °C |
| Boiling Point | 39 °C |
| Flash Point | -2 °C |
| Water Solubility | Moderate |
| Solubility | Soluble in organic solvents |
| Vapor Pressure | 520 mmHg at 20 °C |
| Vapor Density | 2.0 (air=1) |
| pKa | 3.57 |
| pH | 3-4 |
Methyl Isocyanate Safety and Hazards
Methyl isocyanate (MIC) poses significant safety hazards. It is highly toxic to humans and can cause severe respiratory and eye irritation. Inhalation of its vapors can lead to respiratory distress and damage to the lungs. Exposure to high concentrations can result in pulmonary edema and even death. Direct contact with the skin or eyes may cause burns and chemical injuries. It is also highly flammable and can form explosive mixtures in the air. Proper safety measures, including the use of protective equipment and adequate ventilation, are crucial when handling MIC to minimize the risk of accidents and ensure the well-being of workers and the surrounding environment.
| Hazard Symbols | T, C, F, Xi |
| Safety Description | Highly toxic and flammable. Use with caution. Avoid inhalation, skin, and eye contact. Use proper protective equipment and ventilation. |
| UN IDs | UN 2487 (MIC) |
| HS Code | 2929.90.90 |
| Hazard Class | 6.1 (Toxic substances) |
| Packing Group | II (Medium danger) |
| Toxicity | Highly toxic to humans and animals. Can cause severe respiratory and eye irritation. Inhalation may lead to respiratory distress and lung damage. |
Methyl Isocyanate Synthesis Methods
The synthesis of MIC involves reacting phosgene gas with liquid methylamine in the presence of a catalyst, such as triethylamine, at low temperatures and carefully controlled conditions. This reaction yields MIC and produces hydrogen chloride as a byproduct.
Another method to synthesize MIC is by reacting methylamine with cyanogen chloride in the presence of an excess of methylamine and a base, such as sodium hydroxide. This process generates MIC and produces hydrogen chloride as a byproduct.
To synthesize MIC, one can react methanol with cyanogen chloride or cyanuric chloride in the presence of a base such as sodium hydroxide or potassium hydroxide. The reaction between cyanogen chloride or cyanuric chloride and methanol, in the presence of the base, produces MIC.
It is crucial to note that the synthesis of MIC necessitates specialized equipment and careful handling due to its toxic and hazardous nature. Personnel should follow safety precautions, wear appropriate protective equipment, and adhere to proper handling procedures to ensure their well-being and minimize the risk of accidents.
Methyl Isocyanate Uses
MIC finds wide-ranging applications due to its unique properties and reactivity. Here are some key uses of MIC:
- Companies primarily use MIC to produce carbamate-based insecticides, which are essential for controlling pests in agriculture. MIC acts as a crucial raw material for synthesizing these agricultural chemicals.
- Manufacturers utilize MIC in creating polyurethane foams, which are present in various products like mattresses, cushions, and insulation materials.
- MIC finds application in the manufacturing of elastomers, which contribute to the production of flexible materials such as synthetic rubber and coatings.
- Pharmaceutical companies employ MIC in synthesizing pharmaceutical compounds and intermediates, playing a vital role in manufacturing specific medications.
- MIC is a key component in the production of herbicides, which are necessary for effectively controlling and eliminating unwanted plants in agriculture and horticulture.
- Manufacturers use MIC as a cross-linking agent in producing strong-bonding adhesives and sealants.
- MIC plays a role in producing dyes and pigments, enabling the coloring of various products and materials.
- MIC serves as a chemical intermediate in synthesizing diverse organic compounds, contributing to the development of industries such as plastics, paints, and coatings.
- MIC has applications in the production of specialty chemicals, including corrosion inhibitors and industrial cleaners.
The versatile reactivity and applications of methyl isocyanate make it a significant contributor to the development of numerous consumer and industrial products across various sectors.
Questions:
Q: How is methyl isocyanate made?
A: MIC is typically synthesized by reacting methylamine with either phosgene or cyanogen chloride, under controlled conditions and with appropriate catalysts or bases.
Q: How much methyl isocyanate was released in Bhopal?
A: Approximately 40 metric tons of MIC were released in the tragic Bhopal gas disaster in 1984, causing significant loss of life and widespread health effects.
Q: How does methyl isocyanate affect the body?
A: MIC can have severe health effects when inhaled or exposed to the skin or eyes, including respiratory distress, lung damage, eye irritation, and in high concentrations, even death.
Q: What are the health impacts of the toxin, methyl isocyanate, on humans?
A: Health impacts of MIC on humans include respiratory and eye irritation, lung damage, pulmonary edema, and potential long-term effects on the respiratory system and overall health.
Q: What is methyl isocyanate?
A: MIC is a volatile and toxic chemical compound used in the production of pesticides, polyurethane foams, elastomers, and various other industrial applications.
Q: Is methyl isocyanate heavier than water?
A: No, MIC has a lower density than water, with a specific gravity of approximately 0.97 g/mL.
Q: How does methyl isocyanate kill?
A: MIC can be lethal when inhaled in high concentrations, causing severe damage to the respiratory system, leading to respiratory distress, pulmonary edema, and potentially fatal outcomes.