Naphthalene

Molecular Structure:

IUPAC Name: Naphthalene
Synonyms of Naphthalene (CAS NO.91-20-3): Albocarbon ; Camphor tar ; Dezodorator ; Naftalen ; Naphthalene ; Naphthaline ; Naphthalene, crude or refined ; Naphthalene, molten
CAS NO: 91-20-3
Molecular Formula: C₁₀H₈
Molecular Weight: 128.17
EINECS: 202-049-5
Index of Refraction: 1.632
Molar Refractivity: 44.09 cm³
Molar Volume: 123.5 cm³
Surface Tension: 40.2 dyne/cm
Density: 1.037 g/cm³
Flash Point: 78.9 °C
Enthalpy of Vaporization: 43.93 kJ/mol
Boiling Point: 221.5 °C at 760 mmHg
Vapour Pressure: 0.159 mmHg at 25°C
Melting Point: 80-82 °C(lit.)
Storage temp: APPROX 4°C
Water Solubility: 30 mg/L (25 °C)
Appearance: white to almost white crystals, crystalline flakes
Product Categories of Naphthalene (CAS NO.91-20-3): Intermediates of Dyes and Pigments;Naphthalene;Organoborons;Highly Purified Reagents;Other Categories;Zone Refined Products;Analytical Chemistry;Standard Solution of Volatile Organic Compounds for Water & Soil Analysis;Standard Solutions (VOC);Chemistry;Naphthalenes;Analytical Standards;AromaticsVolatiles/ Semivolatiles;Volatiles/ Semivolatiles;Arenes;Building Blocks;Organic Building Blocks;Alpha Sort;Chemical Class;FumigantsVolatiles/ Semivolatiles;Hydrocarbons;Insecticides;N;NA - NIAnalytical Standards;NaphthalenesChemical Class;Neats;N-OAlphabetic;Pesticides

In 1819-1820, at least two chemists reported a white solid with a pungent odor derived from the distillation of coal tar.
In 1821, John Kidd described many of this substance's properties and the means of its production, and proposed the name naphthaline, as it had been derived from a kind of naphtha (a broad term encompassing any volatile, flammable liquid hydrocarbon mixture, including coal tar).
In 1826, naphthaline's chemical formula was determined by Michael Faraday.
The structure of two fused benzene rings was proposed by Emil Erlenmeyer in 1866, and confirmed by Carl Gr?be three years later.

 Naphthalene (CAS NO.91-20-3) has widely uses:
1. It can be used as a chemical intermediate, mainly used as a precursor to other chemicals.The single largest use of naphthalene is the industrial production of phthalic anhydride, although more phthalic anhydride is made from o-xylene. Naphthalene is also used in the synthesis of 2-naphthol, a precursor for various dyestuffs, pigments, rubber processing chemicals and other miscellaneous chemicals and pharmaceuticals.
2. Used as a wetting Agent/Surfactant: Alkyl naphthalene sulfonates (ANS) are used in many industrial applications as detergent wetting agents that effectively disperse colloidal systems in aqueous media. The major commercial applications are in the agricultural chemical industry, which uses Alkyl naphthalene sulfonates (ANS) for wettable powder and wettable granular (dry-flowable) formulations, and the textile and fabric industry, which utilizes the wetting and defoaming properties of Naphthalene for bleaching and dyeing operations.
3. Naphthalene can be used as a fumigant,this is the most familiar use of Naphthalene,such as in mothballs although 1,4-dichlorobenzene (or p-dichlorobenzene) is now more widely used.
4. Niche applications:It is used in pyrotechnic special effects such as the generation of black smoke and simulated explosions.

 Naphthalene (CAS NO.91-20-3) is produced from coal tar. In the coal tar process, coal tar is processed through a tar-distillation step where approximately the first 20 wt % of distillate (chemical oil) is removed. The chemical oil, which contains practically all the naphthalene present in the tar, is reserved for further processing, and the remainder of the tar is distilled further to remove additional creosote oil fractions until a coal-tar pitch of desirable consistency and properties is obtained. The chemical oil is processed to remove the tar acids by contacting with dilute sodium hydroxide and, in a few cases, is next treated to remove tar bases by washing with sulfuric acid.
 Crude naphthalene product is obtained by fractional distillation of the tar acid-free chemical oil, and the distillation may be accomplished in either a batch process or a continuous process. The tar acid-free chemi-cal oil is charged to the system, where most of the low boiling components such as benzene, xylene, and toluene, are removed in the light-solvent col-umn. The chemical oil next is fed to the solvent column, which is operated under vacuum, where a product containing the prenaphthalene components is taken overhead. This product, which is called coal-tar naphtha or crude heavy solvent, typically has a boiling range of approximately 130 to 200 °C and is used as a general solvent and as a feedstock for hydrocarbon-resin manufacture because of its high content of compounds such as indene and coumarone.
The naphthalene-rich bottoms from the solvent column then are fed to the naphthalene column where a naphthalene product (95% naphthalene) is produced. The naphthalene column is operated at near atmospheric pressure to avoid difficulties that are inherent to vacuum distillation of this product, for example, naphthalene-filled vacuum jets and lines. A side stream that is rich in methylnaphthalenes may be taken near the bottom of the naphthalene column.
 The main impurity in crude 78 °C coal-tar naphthalene is sulfur that is present in the form of thionaphthene (1 to 3%). Methyl- and dimethyl-naphthalenes also are present (1 to 2%) with lesser amounts of indene, methylindenes, tar acids, and tar bases.

Reported in EPA TSCA Inventory. EPA Genetic Toxicology Program. Community Right-To-Know List.

Hazard Codes: Xn,N,F,T
Risk Statements: 22-40-50-67-65-38-11-39/23/24/25-52/53
R11: Highly flammable. 
R22: Harmful if swallowed. 
R38: Irritating to skin. 
R40: Limited evidence of a carcinogenic effect. 
R50: Very toxic to aquatic organisms. 
R65: Harmful: may cause lung damage if swallowed.
R67: Vapours may cause drowsiness and dizziness. 
R52/53: Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment. 
R39/23/24/25: Toxic: danger of very serious irreversible effects through inhalation, in contact with skin and if swallowed
Safety Statements: 36/37-46-60-61-62-45-16-7
S36/37: Wear suitable protective clothing and gloves. 
S46: If swallowed, seek medical advice immediately and show this container or label. 
S60: This material and its container must be disposed of as hazardous waste. 
S61: Avoid release to the environment. Refer to special instructions / safety data sheets. 
S62: If swallowed, do not induce vomitting; seek medical advice immediately and show this container or label. 
S45: In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) 
S16: Keep away from sources of ignition. 
S7: Keep container tightly closed.
RIDADR: UN 1334 4.1/PG 3
WGK Germany: 3
RTECS: QJ0525000
HazardClass: 4.1
PackingGroup: III
HS Code: 29029010

OSHA PEL: TWA 10 ppm; STEL 15 ppm
ACGIH TLV: TWA 10 ppm; STEL 15 ppm; Not Classifiable as a Human Carcinogen
DFG MAK: Confirmed Animal Carcinogen with Unknown Relevance to Humans
DOT Classification:  4.1; Label: Flammable Solid

For occupational chemical analysis use OSHA: #35 or NIOSH: Hydrocarbons, Aromatic, 1501.

General Information: As in any fire, wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Dusts at sufficient concentrations can form explosive mixtures with air. Will burn if involved in a fire. Use water spray to keep fire-exposed containers cool. Combustible solid.
Extinguishing Media: Use carbon dioxide or dry chemical 
Handling: Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Use spark-proof tools and explosion proof equipment. Take precautionary measures against static discharges. Do not get on skin or in eyes. Do not ingest or inhale. Use only in a chemical fume hood.
Storage: Keep Naphthalene (CAS NO.91-20-3) away from sources of ignition. Store in a cool, dry, well-ventilated area away from incompatible substances.