Chemical Properties |
colourless liquid with a pleasant odour |
Uses |
Solvent for nitrocellulose, acetylcellulose, and many resins and oils; manufacture of artificial leather. |
General Description |
A clear colorless liquid with a fragrant odor. Moderately toxic. Flash point 14°F. Vapors heavier than air. |
Air & Water Reactions |
Highly flammable. Water soluble. |
Reactivity Profile |
Methyl acetate presents a fire or explosion hazard when exposed to strong oxidizing agents. Emits irritating fumes and acrid smoke when heated to decomposition, [Lewis, 3rd ed., 1993, p. 826]. Methyl acetate reactivity is consistent with other compounds of the ester group. |
Hazard |
Flammable, dangerous fire and explosion risk, explosive limits in air 3–16%. Irritant to respiratory tract. Headache, dizziness, nausea, eye damage (degeneration of ganglion cells in the retina). |
Health Hazard |
(Very similar to those of methyl alcohol, which constitutes 20% of commercial grade.) Inhalation causes headache, fatigue, and drowsiness; high concentrations can produce central nervous system depression and optic nerve damage. Liquid irritates eyes and may cause defatting and cracking of skin. Ingestion causes headache, dizziness, drowsiness, fatigue; may cause severe eye damage. |
Fire Hazard |
Behavior in Fire: Vapor is heavier than air and may travel a considerable distance to a source of ignition and flash back. |
Safety Profile |
Moderately toxic by several routes. A human systemic irritant by inhalation. A moderate skin and eye irritant. Mutation data reported. Dangerous fire hazard when exposed to heat, flame, or oxidizers. Moderate explosion hazard when exposed to heat or flame. When heated to decomposition it emits acrid smoke and fumes. See also ESTERS. |
Purification Methods |
Methanol in methyl acetate can be detected by measuring its solubility in water. At 20o, the solubility of methyl acetate in water is ca 35g per 100mL, but 1% MeOH confers complete miscibility. Methanol can be removed by conversion to methyl acetate, by refluxing for 6hours with acetic anhydride (85mL/L), followed by fractional distillation. Acidic impurities can be removed by shaking with anhydrous K2CO3 and distilling. An alternative treatment is with acetyl chloride, followed by washing with concentrated NaCl and drying with CaO or MgSO4. (Solid CaCl2 cannot be used because it forms a crystalline addition compound.) Distillation from copper stearate destroys peroxides. Free alcohol or acid can be eliminated from methyl acetate by shaking with strong aqueous Na2CO3 or K2CO3 (three times), then with aqueous 50% CaCl2 (three times), saturated aqueous NaCl (twice), drying with K2CO3 and distilling it from P2O5. [Beilstein 2 IV 122.] |