Product Identification
【Product Name】3,4-Dihydroxy-3-cyclobutene-1,2-dione
【Synonyms】Quadratic acid  方形酸
【CAS】2892-51-5
【Formula】C4H2O4
【Molecular Weight】114.06
【EINECS】220-761-4
【RTECS】GU1800000
【RTECS Class】Tumorigen
【Beilstein/Gmelin】774275
【Beilstein Reference】4-08-00-02701
【EC Class】corrosive

Physical and Chemical Properties
【Appearance】odorless slightly beige solid
【Solubility in water】Very soluble
【Melting Point】293
【Vapor Pressure】0.075 (20℃)
【Density】1 g/cm3 (20℃)
【pKa/pKb】0.52 (pKa)
【Usage】Treatment of warts and autoimmune hair loss.

First Aid Measures
【Ingestion】If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid.
【Inhalation】Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.
【Skin】Get medical aid. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes.
【Eyes】Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.

Handling and Storage
【Storage】Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances.
【Handling】Wash thoroughly after handling. Use only in a well ventilated area. Avoid contact with eyes, skin, and clothing. Avoid ingestion and inhalation.

Hazards Identification
【Ingestion】The toxicological properties of this substance have not been fully investigated.
【Inhalation】The toxicological properties of this substance have not been fully investigated.
【Skin】May cause skin sensitization, an allergic reaction, which becomes evident upon re-exposure to this material.
【Eyes】May cause eye irritation.
【EC Risk Phrase】R 34
【EC Safety Phrase】S 26 36/37/39 45
【UN (DOT)】3261

Exposure Controls/Personal Protection
【Personal Protection】Eyes: Wear appropriate protective eyeglasses or chemical safety ggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
【Respirators】Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.

Fire Fighting Measures
【Flash Point】190℃
【Autoignition】400℃
【Fire Fighting】Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Extinguishing media: Use foam, dry chemical, or carbon dioxide.

Accidental Release Measures
【Small spills/leaks】Sweep up or absorb material, then place into a suitable clean, dry, closed container for disposal.

Stability and Reactivity
【Disposal Code】3
【Stability】Stable under normal temperatures and pressures.
【Incompatibilities】Strong oxidizing agents, strong bases.
【Decomposition】Carbon monoxide, carbon dioxide.

Transport Information
【UN Number】3261
【HS Code】2914 40 90