Oxalic acid

Molecular Formula: H₂C₂O₄
Molecular Weight: 90.03 g/mol
EINECS: 205-634-3
Density: 1.9 g/mL
Flashing point: 101-157 °C
Melting point: 189-191 °C
Water solubility: 90 g/L (20 °C)
Appearance: Odorless white solid
Structure of Oxalic acid (CAS NO.144-62-7):
                                 
IUPAC Name: Oxalic acid
Product Category of Oxalic acid (CAS NO.144-62-7): Intermediates;Water Ttreatment Chemicals;Alphabetic;Carbonyl Compounds;Carboxylic Acids;Complexometric Solutions

 Oxalic acid (CAS NO.144-62-7) is used as Bar Keeper's Friend, Zud, some bleaches, and rustproofing treatments, and it is also used as an cadditive to automotive wheel leaners. It is used in platinotype, the early photographic Platinum/Palladium printing process. Oxalic acid is used as a rust remover in such applications as automotive shops and for the restoration of antiques, and as a recommended surface pretreatment for stainless steels (surface etch) before application of solid metal or polymer self-lubricating coatings. It is used for polishing stones and marble, and used in the acid treatment for destroying warts.

Reported in EPA TSCA Inventory.

Poison by subcutaneous route. Moderately toxic by ingestion. A skin and severe eye irritant. Acute oxalic poisoning results from ingestion of a solution of the acid. There is marked corrosion of the mouth, esophagus, and stomach, with symptoms of vomiting, burning abdominal pain, collapse, and sometimes convulsions. Death may follow quickly. The systemic effects are attributed to the removal by the oxalic acid of the calcium in the blood. The renal tubules become obstructed by the insoluble calcium oxalate, and there is profound kidney disturbance. The chief effects of inhalation of the dusts or vapor are severe irritation of the eyes and upper respiratory tract, gastrointestinal disturbances, albuminuria, gradual loss of weight, increasing weakness and nervous system complaints, ulceration of the mucous membranes of the nose and throat, epistaxis, headache, irritation, and nervousness. Oxalic acid has a caustic action on the skin and may cause dermatitis; a case of early gangrene of the fingers resembling that caused by phenol has been described. More severe cases may show albuminuria, chronic cough, vomiting, pain in the back, and gradual emaciation and weakness. The skin lesions are characterized by cracking and fissuring of the skin and the development of slow-healing ulcers. The skin may be bluish in color, and the nails brittle and yellow. Violent reaction with furfuryl alcohol, Ag, NaClO₃, NaOCl. When heated to decomposition it emits acrid smoke and irritating fumes. See also OXALATES.
Hazard Codes: Xn
Risk Statements: 21/22-63-34 
R21/22:Harmful in contact with skin and if swallowed. 
R34:Causes burns. 
R63:Possible risk of harm to the unborn child.
Safety Statements: 24/25-23-36/37/39-27-26 
S23:Do not breathe vapour. 
S24/25:Avoid contact with skin and eyes. 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S27:Take off immediately all contaminated clothing. 
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection.

 Oxalic acid , its cas register number is 144-62-7. It also can be called Ethanedionic acid ; and Oxalic acid anhydrous . It is hazardous, so the first aid measures and others should be known. Such as: When on the skin: first, should flush skin with plenty of water immediately for at least 15 minutes while removing contaminated clothing. Secondly, get medical aid. Or in the eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Then get medical aid soon. While, it's inhaled: Remove from exposure and move to fresh air immediately. Give artificial respiration while not breathing. When breathing is difficult, give oxygen. And as soon as to get medical aid. Then you have the ingesting of the product: If victim is conscious and alert, give 2-4 cupfuls of milk or water. Get medical aid immediately. Notes to physician: Treat supportively and symptomatically.
In addition, Oxalic acid (CAS NO.144-62-7) absorbs moisture or water from the air. It is not compatible with Metals, strong oxidizing agents, strong bases, acid chlorides, sodium hypochlorite, steel, mercury, silver, sodium chloride, chlorites, and you must not take it with incompatible materials. And also prevent it to broken down into hazardous decomposition products: formic acid, carbon monoxide, carbon dioxide.