ACETALDEHYDE (ETHANAL)

ACETALDEHYDE
PRODUCT IDENTIFICATION
CAS NO.	75-07-0
EINECS NO.	200-836-8
FORMULA	CH₃CHO
MOL WT.	44.05
H.S. CODE	2912.12
TOXICITY	Oral rat LD50: 661 mg/kg
SYNONYMS	Acetic aldehyde; Acetylaldehyde; Ethylaldehyde; Ethanal;
Acetaldehyd; Aldehyde acetique; Aldeide acetica; Octowy aldehyd; Acetylaldehyde;
DERIVATION
CLASSIFICATION
GENERAL DESCRIPTION
Acetaldehyde, also called Ethanal (CH3CHO), is an aldehyde used as a starting material in the synthesis of acetic acid, n-butyl alcohol, ethyl acetate, and other chemical compounds. It is manufactured by the oxidation of ethyl alcohol and by the catalytic hydration of acetylene (in Germany). Pure acetaldehyde is a colourless, miscible with water, flammable liquid with pungent, fruity odour; it boils at 20.8 C.
PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL STATE	easily volatile clear liquid
MELTING POINT	-123 C
BOILING POINT	20 - 21 C
SPECIFIC GRAVITY	0.78 - 0.79
SOLUBILITY IN WATER	Miscible
pH
VAPOR DENSITY	1.52
AUTOIGNITION	230 C
NFPA RATINGS	Health: 3; Flammability: 4; Reactivity: 2
REFRACTIVE INDEX
FLASH POINT	-38 C
STABILITY	`Unstable in air. May undergo autopolymerization with metals or acids.`
APPLICATIONS
The main use of acetaldehyde is as an intermediate for the synthesis of other chemicals. The main derivatives of Acetaldehyde are the oxygenated solvent Ethyl Acetate, Pentaerythritol (used in the production of synthetic resins for the paint industry) and Pyridines. Acetaldehyde is used in the production of perfumes, polyester resins, and basic dyes. Acetaldehyde is also used as a solvent in the rubber, tanning, and paper industries, as a fruit and fish preservative, as a flavoring agent, for hardening gelatin, as a denaturant for alcohol and in fuel compositions.
SALES SPECIFICATION
APPEARANCE	clear liquid
PURITY	99.7% min
COLOR, APHA	10 max
SPECIFIC GRAVITY	0.78 - 0.79 (20/20 C)
BOILING POINT	21 C
PRECAUTION IN HANDLING
Acetaldehyde is not compatible with strong oxidizers, acids, alcohols, ammonia, amines, phenols, ketones, acid anhydrides and halogens. Acetaldehyde reacts violently with anhydrous ammonia, hydrogen cyanide, hydrogen sulfide and alkaline materials (such as sodium hydroxide). Acetaldehyde reacts with air to form unstable peroxides which can explode. Store in tightly closed airtight containers in a cool, dark, well-ventilated area. Nitrogen or another inert gas should be used as a "blanket" over liquid Acetaldehyde in storage containers. Sources of ignition, such as smoking and open flames, are prohibited where Acetaldehyde is handled, used, or stored. Metal containers involving the transfer of Acetaldehyde should be grounded and bonded. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arresters. Use only non-sparking tools and equipment, especially when opening and closing containers of Acetaldehyde. Prior to working with Acetaldehyde you should be trained on its proper handling and storage.
TRANSPORTATION
PACKING	150kgs in drum
HAZARD CLASS
UN NO.
OTHER INFORMATION
`European Hazard Symbols: XN F+, Risk Phrases: 12-36/37-40, Safety Phrases: 16-33-36/37`
DESCRIPTION OF ALDEHYDE
Aldehydes are organic compounds containing -CHO radical, in which a carbon atom forms a double bond with an oxygen atom and is also bonded to a hydrogen atom and another group denoted by R, which can be a second hydrogen atom, an alkyl group, or an aryl group. The most important and the simplest examples are methanal (formaldehyde), HCOH, and ethanal (acetaldehyde), CH₃CHO.( In systematic chemical nomenclature, aldehyde names end with the suffix -al). Formaldehyde is used to make synthetic resins by reaction with phenols, urea, and melamine, as a chemical intermediate, as an embalming fluid, and as a disinfectant. Acetaldehyde is used chiefly to manufacture acetic acid. They are unpleasant-smelling liquids widely used in the chemical industry, whereas aromatic aldehydes frequently have pleasant smells and are used widely as flavourings and perfumes. An example is benzaldehyde (benzenecarbaldehyde, C₆H₅CHO), a derivative of benzene with an aldehyde group attached to the ring. It is a colourless oil smelling of almonds offer applications to both in perfumes and flavourings. Aldehydes are formed by oxidation of primary alcohols; further oxidation yields carboxylic acids. Aldehydes have certain characteristic addition and condensation reactions. Aldehydes can be reduced to primary alcohols (ketones to secondary alcohols). Aldehydes form cyanohydrins with hydrogen cyanide, acetals with alcohol, yellow-orange solid derivatives with DNP ( 2,4-dinitrophenylhydrazones) and undergo condensation reactions to yield oximes (compounds containing the group C:NOH), hydrazones (organic compounds containing the group =C:NNH₂), and semicarbazones (organic compounds containing the unsaturated group =C:N.NH.CO.NH₂). Aldehydes readily polymerize.