Pyrocatechol Chemical Properties
- Melting point:
- 103 °C
- Boiling point:
- 245 °C(lit.)
- 1,371 g/cm3
- vapor density
- 3.8 (vs air)
- vapor pressure
- 1 mm Hg ( 75 °C)
- refractive index
- 1.6120 (estimate)
- Flash point:
- 279 °F
- storage temp.
- Store at RT.
- Crystalline Flakes
- 9.85(at 20℃)
- white to faintly beige
- 6 (100g/l, H2O, 20℃)
- explosive limit
- Water Solubility
- 430 g/L (20 ºC)
- Air & Light Sensitive
- Exposure limits
- TLV-TWA 5 ppm (～22 mg/m3) (ACGIH). .
- Stable. Substances to be avoided include acid chlorides, acid anhydrides, bases, oxidizing agents, nitric acid. Light sensitive; may discolour on exposure to air. Combustible.
- CAS DataBase Reference
- 120-80-9(CAS DataBase Reference)
- NIST Chemistry Reference
- EPA Substance Registry System
- Catechol (120-80-9)
- Hazard Codes
- Risk Statements
- Safety Statements
- UN 2811 6.1/PG 3
- WGK Germany
- HS Code
- 2907 29 00
- Hazardous Substances Data
- 120-80-9(Hazardous Substances Data)
- LD50 in mice (mg/kg): 260 orally; 190 i.p. (Lehman)
Pyrocatechol Usage And Synthesis
Catechol is a white crystalline solid. Turns brown on contact with light and air.
Pyrocatechol is used in photography, in dyeing fur, and as a topical antiseptic.
In photography; dyeing fur; as reagent.
Pyrocatechol may be obtained by the fusion of o-phenolsulfonic acid with alkali, by heating chorophenol with a solution of sodium hydroxide at 200°C in an autoclave, or by cleavage of the methyl ether group of guaiacol (obtained from beechwood tar) with hydriodic acid.
A colourless crystalline PHENOL containing two hydroxyl groups. It is used in photographic developing.
Solid; white; odorless. Sinks and mixes with water.
Air & Water Reactions
Turns brown on exposure to air and light, especially when moist. Water soluble. Aqueous solutions soon turn brown on exposure to air and light.
POISONOUS GASES MAY BE PRODUCED WHEN HEATED. Pyrocatechol may form toxic fumes at high temperatures. [USCG, 1999]. Pyrocatechol can react with acid chlorides, acid anhydrides, bases and oxidizing agents. Pyrocatechol reacts violently on contact with concentrated nitric acid. Pyrocatechol acts as a reducing agent .
Strong irritant. Toxic by skin absorption. Eye and upper respiratory tract irritant, and der- matitis. Possible carcinogen.
DUST: Irritating to eyes, nose and throat. If inhaled will cause coughing or difficult breathing. SOLID: Will burn skin and eyes. Harmful if swallowed.
Acute oral and percutaneous toxicity of pyrocatechol is greater than that of phenol; inhalation toxicity is less than that of phenol. The toxic symptoms include weakness, muscular pain, dark urine, tremor, dyspnea, and convulsions. Large amounts can produce degenerative changes in renal tubules. Large doses can cause death due to respiratory failure. Skin contact can cause eczematous dermatitis.
LD50 value, oral (rats): 260 mg/kg
LD50 value, skin (rabbits): 800 mg/kg.
Combustible. POISONOUS GASES MAY BE PRODUCED WHEN HEATED. May form toxic fumes at high temperatures.
Poison by ingestion, subcutaneous, intraperitoneal, intravenous, and parenteral routes. Moderately toxic by skin contact. Experimental reproductive effects. Can cause dermatitis on skin contact. An allergen. Human mutation data reported. Questionable carcinogen. Systemic effects sirmlar to those of phenol. Combustible when exposed to heat or flame; can react vigorously with oxidizing materials. Hypergolic reaction with concentrated nitric acid. To fight fire, use water, CO2, dry chemical. When heated to decomposition it emits acrid smoke and irritating fumes. See also PHENOL.
Used as a chemical intermediate; pharmaceutical and veterinary drug; as an antiseptic; in photography; in dyestuff manufacture and application. It is also used in electroplating, in the formulation of specialty inks; in antioxidants; and light stabilizers.
Pyrocatechol has been extensively studied for its role in carcinogenesis of the rat glandular stomach; it was concluded that pyrocatechol is carcinogenic. When rats and mice were administered 0.8% pyrocatechol in their feed for life, there was an increase in glandular stomach adenocarcinoma in both male and female rats. Pyrocatechol also caused hyperplasia of the glandular stomach in both rats and mice, a mechanism that could cause promotion of carcinogen-initiated cells; no effects on the esophagus or urinary bladder were reported. There were no cutaneous neoplasms when pyrocatechol was applied in dermal studies. Pyrocatechol may be classified as a cocarcinogen because it enhanced the number and/or incidence of lesions in the stomach induced by several carcinogenic nitrosamines and cutaneous neoplasms when administered dermally together with several carcinogens.
UN 2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required.
Crystallise catechol from *benzene or toluene and sublime it in vacuo. [Rozo et al. Anal Chem 58 2988 1986, Beilstein 6 IV 5557.]
Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides.
Pyrocatechol Preparation Products And Raw materials
- ALIZARIN COMPLEXONE
- 3,4-DIMETHOXYBENZOYL CHLORIDE
- 3,4,5-Trimethoxybenzoyl chloride
- Pyrocatechol Violet
- 010-82848833- ;010-82848833-