IUPAC Name: Pyridine-3-carboxylic acid
Molecular Formula: C₆H₅NO₂
Molecular Weight: 123.11 g/mol
Canonical SMILES: C1=CC(=CN=C1)C(=O)O
InChI: InChI=1/C6H5NO2/c8-6(9)5-2-1-3-7-4-5/h1-4H,(H,8,9)
EINECS: 200-441-0
Classification Code: Antihyperlipidemic; Antilipemic Agents; Antimetabolites; Cardiovascular Agents; Drug / Therapeutic Agent; Growth Substances; Human Data; Micronutrients; Tumor data; Vasodilator Agents; Vitamin B Complex; Vitamin; Vitamins
H-Bond Donor: 1
H-Bond Acceptor: 3
Density: 1.293 g/cm³
Flash Point: 130.7 °C
Enthalpy of Vaporization: 56.18 kJ/mol
Boiling Point: 292.5 °C at 760 mmHg
Melting Point: 236-239 °C(lit.)
Storage temperature: 0-6°C
Water Solubility: 1.80E+04 mg/L at 25 °C
Henry's Law Constant: 5.11E-11 atm-m³/mole at 25 °C
Atmospheric OH Rate Constant: 1.72E-13 cm³/molecule-sec at 25 °C
Vapour Pressure of Niacin (CAS NO.59-67-6): 5.70E-06 mm Hg at 25 °C

In 1873, Niacin was first described by Hugo Weidel in his studies of nicotine.Niacin was extracted from livers by Conrad Elvehjem who later identified the active ingredient, then referred to as the "pellagra-preventing factor" and the "anti-blacktongue factor." When the biological significance of nicotinic acid was realized, it was thought appropriate to choose a name to dissociate it from nicotine, in order to avoid the perception that vitamins or niacin-rich food contains nicotine, or that cigarettes contain vitamins. The resulting name 'niacin' was derived from nicotinic acid + vitamin.
 Niacin is referred to as Vitamin B3 because it was the third of the B vitamins to be discovered. It has historically been referred to as "vitamin PP."

 Niacin (CAS NO.59-67-6) feed grade is used as vitamin for poultry, swines, ruminants, fish, dogs and cats, etc. It is also used as intermediate for nicotinic acid derivatives and technical applications. Niacin USP is used for food fortification, as dietary supplement and as an intermediate of pharmaceuticals,as dietary supplement and as an intermediate of pharmaceuticals. It is a brand name for a sustained release Niacin tablet, which is used to reduce cholesterol.

 Niacin (CAS NO.59-67-6) can be selectively isolated from the hydrolysis by varying the hydrolysis time and nitrite concentration. A higher hydrolysis temperature favors production of niacin.

Reported in EPA TSCA Inventory.

Poison by intraperitoneal route. Moderately toxic by ingestion, intravenous, and subcutaneous routes. Human systemic effects: change in clotting factors, changes in platelet count. Questionable carcinogen with experimental carcinogenic data. When heated to decomposition it emits toxic fumes of NO_x.
Hazard Codes: Xi
Risk Statements: 36/37/38 
R36/37/38: Irritating to eyes, respiratory system and skin.
Safety Statements: 26-36-24/25 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36: Wear suitable protective clothing. 
S24/25: Avoid contact with skin and eyes.
WGK Germany of Niacin (CAS NO.59-67-6): 1

 Niacin (CAS NO.59-67-6), its Synonyms are Nicotinic acid ; 3-Pyridinecarboxylic acid ; 3-Carboxypyridine ; Acide nicotinique ; Acido nicotinico ; Acidum nicotinicum ; Akotin ; Apelagrin ; Kyselina nikotinova ; Enduracin ; Daskil ; Davitamon PP ; Diacin ; Direktan ; Niaspan Titration Starter Pack ; Nicacid ; Nicagin ; Nicamin ; Nicangin ; Pyridine-3-carboxylic acid ; Pyridine-beta-carboxylic acid ; Pyridine-carboxylique-3 ; Pyridinecarboxylic acid, 3- . It is odorless white crystalline powder with a feebly acid taste.