Name | Acetaldehyde |
Synonyms | Ethanal Acetaldeyd Acetaldehyd Acetaldeyde Acetacdehyde Acetaldehyde Ethyl aldehyde Acetic Aldehyde FORMALIN, CARSONS acetaldehyde(ethanal) FORMALDEHYDE, BUFFERED FORMALDEHYDE, CARSON-MILLON FORMALDE-FRESH SOLUTION, BUFFERED |
CAS | 75-07-0 |
EINECS | 200-836-8 |
InChI | InChI=1/C2H4O/c1-2-3/h2H,1H3 |
InChIKey | IKHGUXGNUITLKF-UHFFFAOYSA-N |
Molecular Formula | C2H4O |
Molar Mass | 44.05 |
Density | 0.785 g/mL at 25 °C (lit.) |
Melting Point | -125 °C (lit.) |
Boling Point | 21 °C (lit.) |
Flash Point | 133°F |
JECFA Number | 80 |
Water Solubility | > 500 g/L (20 ºC) |
Solubility | alcohols: soluble |
Vapor Presure | 52 mm Hg ( 37 °C) |
Vapor Density | 1.03 (vs air) |
Appearance | solution |
Specific Gravity | 0.823 (20/4℃) (?90% Soln.) |
Color | White to off-white |
Odor | Pungent, fruity odor detectable at 0.0068 to 1000 ppm (mean = 0.067 ppm) |
Exposure Limit | TLV-TWA 180 mg/m3 (100 ppm) (ACGIH),360 mg/m3 (200 ppm) (NIOSH); STEL270 mg/m3 (150 ppm); IDLH 10,000 ppm. |
Merck | 14,39 |
BRN | 505984 |
pKa | 13.57(at 25℃) |
PH | 5 (10g/l, H2O, 20℃) |
Storage Condition | 2-8°C |
Stability | Stable, but air sensitive. Substances to be avoided include strong oxidizing agents, strong acids, reducing agents, alkalies, halogens, halogen oxides. Highly flammable. Vapour/air mixtures explosive |
Sensitive | Air Sensitive |
Explosive Limit | 4-57%(V) |
Refractive Index | n20/D 1.377 |
Physical and Chemical Properties | Colorless, flammable, volatile, easy to flow of liquid, spicy and pungent odor. melting point -123.5 ℃ boiling point 20.16 ℃ relative density 0.7780 refractive index 1.3311 flash point -38 ℃ solubility in water, ethanol, diethyl ether, benzene, gasoline, toluene, xylene and acetone are miscible. |
Use | Mainly used for the preparation of acetic acid, acetic anhydride, butyl aldehyde, octanol, pentaerythritol, triacetaldehyde and other important chemical raw materials |
Risk Codes | R23/24/25 - Toxic by inhalation, in contact with skin and if swallowed. R34 - Causes burns R40 - Limited evidence of a carcinogenic effect R43 - May cause sensitization by skin contact R36/37 - Irritating to eyes and respiratory system. R12 - Extremely Flammable R67 - Vapors may cause drowsiness and dizziness R11 - Highly Flammable R41 - Risk of serious damage to eyes R22 - Harmful if swallowed R10 - Flammable R19 - May form explosive peroxides |
Safety Description | S36/37 - Wear suitable protective clothing and gloves. S33 - Take precautionary measures against static discharges. S16 - Keep away from sources of ignition. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. |
UN IDs | UN 1198 3/PG 3 |
WGK Germany | 2 |
RTECS | LP8925000 |
FLUKA BRAND F CODES | 10 |
TSCA | Yes |
HS Code | 29121200 |
Hazard Class | 3 |
Packing Group | I |
Toxicity | LD50 orally in rats: 1930 mg/kg (Smyth) |
colorless, flammable, volatile, easy to flow of liquid, spicy and pungent odor. The relative density (do) was 0. 7780. Melting Point -123.5 °c. Boiling point 20. 16 °c. Flash point (closed Cup)- 38 °c. Specific heat capacity (25 °c) 1.41J/(g-°c). Refractive index 3311. Miscible with water, ethanol, ether, benzene, gasoline, toluene, xylene and acetone. The vapor forms an explosive mixture with air, with an explosion limit of 4.0 to 55.0 Vol%. The critical temperature is 181.5 ℃ and the critical pressure is 6.40MPa.
One of the important organic synthesis raw materials, mainly used in the production of acetic acid, acetic anhydride, 2 ethyl hexanol, butanol, pentaerythritol, polyacetaldehyde and trichloroacetaldehyde, and other chemical products.
FEMA | 2003 | ACETALDEHYDE |
olfactory Threshold | 0.0015ppm |
Henry's Law Constant | 7.69 at 25 °C (Snider and Dawson, 1985:Benkelberg et al., 1995) |
NIST chemical information | information provided by: webbook.nist.gov (external link) |
(IARC) carcinogen classification | 2B (Vol. 36, Sup 7, 71) 1999, 1 (Vol. 100E) 2012 |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
preparation method | There are a variety of methods for the preparation of acetaldehyde: in the coal chemical industry, the hydration method of calcium carbide is commonly used to generate acetylene, the acetylene and water in the mercury catalyst or non-mercury catalyst under the action of direct hydration of acetaldehyde; Can also be agricultural products based on the first fermentation of ethanol, and then make the oxidation or dehydrogenation and made; with the development of petrochemical industry, with ethylene as raw material, let oxygen through the hydrochloric acid aqueous solution containing palladium chloride, copper chloride catalyst, One-Step Direct oxidation synthesis of acetaldehyde; Also through the liquefied petroleum gas and light oil (naphtha) the oxidation of acetaldehyde. |
harm to human body | acetaldehyde can be absorbed into the body by inhalation and by ingestion, it can slightly irritate the eyes, skin and respiratory tract. The substance may cause effects on the central nervous system. Acetaldehyde is a first-grade carcinogen that harms the body and can accumulate to cause cancer and other diseases. |
content analysis | take 0.5mol/L hydroxylamine hydrochloride solution 65ml and 0.5mol/L triethanolamine solution 50.0ml, put into a heat-resistant and pressure-resistant bottle that can be safely fixed and has good sealing property. A slow flow of nitrogen gas was fed through a glass tube slightly above the liquid level at the outlet end for 2min to expel the air from the bottle. Accurately weigh about 600mg of the sample, seal it in an ampoule, and put it in the mixed solution in the pressure bottle. A few short glass rods of about 8mm in diameter were added, stoppers were capped and shaken strongly to break the ampoule. The bottles were then shaken at room temperature from time to time and reacted for 30min. Remove the plug after cooling if necessary, and take care to avoid the loss of the contents. Then titrated with 0.5mol/L sulfuric acid to a bluish Blue end point. Blank titration was performed at the same time. Each 0.5mol/L sulfuric acid solution is equivalent to 22.03mg of acetaldehyde (C2H4O). |
toxicity | GRAS(FEMA;FDA,§ 182.60,2000). LD501930mg/kg (rat, oral). |
usage limit | FEMA(mg/kg): Soft drink 3.9; Cold drink 25; Candy 22; Baked goods 12; pudding 6.8; Gum 20~270. |
Applications | mainly used in the preparation of acetic acid, acetic anhydride, ethyl acetate, butanol, pentaerythritol, triacetaldehyde, 3-hydroxybutyraldehyde, chloral and other products GB 2760-1996 provides temporary use of edible spices. Mainly used for the preparation of citrus, Apple, cream and other types of flavor. The largest user of acetaldehyde is the acetic acid industry. In the past, butanol and octanol were also important derivatives of acetaldehyde, and now they are basically replaced by propylene carbonyl synthesis. Other areas of acetaldehyde consumption are the production of pentaerythritol, peracetic acid, pyridine and its derivatives. Domestic production of acetaldehyde is basically used as an intermediate for the production of acetic acid, only a small amount of pentaerythritol, butanol, trichloroacetaldehyde, trimethylolpropane and other products. Acetaldehyde can be used to produce acetal, crotonaldehyde, peroxyacetic acid, hydroxypropionitrile, trichloroacetaldehyde, ethyl acetate, pentaerythritol, acetic anhydride, acetic acid, glyoxal, phenylacrolein, acetal, methylethylamine, diethylamine, α-alanine, pyridine, Α-picoline, β-picoline, γ-picoline. mainly used for the preparation of acetic acid, acetic anhydride, butyraldehyde, octanol, pentaerythritol, triacetaldehyde and other important chemical raw materials used as reducing agent and bactericide |
production method | acetaldehyde has a variety of production methods: 1. Direct oxidation of ethylene ethylene and oxygen through the catalyst containing palladium chloride, copper chloride, hydrochloric acid and water, one-step direct oxidation synthesis of crude acetaldehyde, and then distilled to get the finished product. 2. Ethanol oxidation of ethanol vapor at 300-480 deg C, silver, copper or silver-copper alloy mesh or particle as a catalyst, from air oxidative dehydrogenation of acetaldehyde. Direct hydration of acetylene acetaldehyde was obtained by direct hydration of acetylene and water with mercury catalyst or non-mercury catalyst. Due to the problem of mercury damage, it has been gradually replaced by other methods. Ethanol dehydrogenation method acetaldehyde is produced by dehydrogenation of ethanol under the action of copper catalyst with addition of cobalt, chromium, zinc or other compounds. Oxidation of saturated hydrocarbons. Raw material consumption quota: acetylene water method consumes 99% acetylene per ton of product; Ethanol oxidation consumes 95% ethanol 1200kg; Ethylene oxidation (one-step method) consumes 99% ethylene 710kg, oxygen (99%)300. Commercially available industrial acetaldehyde, ethylene acetaldehyde purity of 99.7%, ethanol purity of 98%. results from the oxidation of ethylene. Obtained by Gas-Phase Hydrogenation of ethanol. Obtained from the simultaneous dry distillation of calcium acetate and calcium formate. Derived from the addition reaction of acetylene and water. |
category | flammable liquid |
toxicity grade | poisoning |
Acute toxicity | oral-rat LD50: 661 mg/kg; Subcutaneous-mouse LD50: 560 mg/kg |
stimulation data | Skin-rabbit 500 mg mild; Eye-rabbit 40 mg severe |
explosive hazard characteristics | explosive when mixed with air |
flammability hazard characteristics | in case of open flame, high temperature, flammable oxidant; Combustion stimulus smoke |
storage and transportation characteristics | The warehouse is ventilated and dried at low temperature; Stored separately from oxidants and acids |
extinguishing agent | dry powder, dry sand, dry stone powder, carbon dioxide, foam |
Occupational Standard | TWA 120 mg/m3; Tel 180 mg/m3 |
spontaneous combustion temperature | 185°C |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |
immediate life-and health-threatening concentrations | 2,000 ppm |