Pyrogallic acid

  • 1,2,3-Benzenetriol
  • Pyrogallol
  • 1,2,3-Trihydroxybenzene
Formula
C6H3(OH)3
Structure
Description
White crystalline solid, odorless, turns grayish on exposure to air and light.
Uses
Developer in photography, making colloidal soln of metals, as mordant for wool, staining leather, process engraving, manufacture various dyes, dyeing furs, hair, analytical chemistry reagent for antimony & bismuth, active reducer for gold, silver & mercury salts, for absorption of oxygen in gas analysis, antipsoriatic.

Registry Numbers and Inventories.
CAS
87-66-1
EC (EINECS/ELINCS)
201-762-9
EC Index Number
604-009-00-6
EC Class
Mutagenic Category 3; Harmful; Dangerous for the Environment
R 20/21/22 52/53 68
S 36/37 61
RTECS
UX2800000
RTECS class
Tumorigen; Drug; Mutagen; Reproductive Effector; Human Data; Primary Irritant
UN (DOT)
2928
Merck
12,8184
Beilstein/Gmelin
907431
Beilstein Reference
4-06-00-07327
Swiss Giftliste 1
G-2821
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C6H6O3
Formula mass
126.11
Melting point, °C
130 - 132
Boiling point, °C
309
Vapor pressure, mmHg
0.0004 (25 C)
Vapor density (air=1)
4.4
Saturation Concentration
6580 ppm (0.66%) at 151.7 C (calculated)
Odor Threshold Odor threshold Odorless
Density
1.453 g/cm3
Solubility in water
600 g/L
Refractive index
1.561 (134 C)
pKa/pKb
9.01 (pKa)
Partition coefficient, pKow
1.23
Heat of fusion
18.6 kJ/mol
Heat of vaporization
57.2 kJ/mol
Heat of combustion
-2667 kJ/mol

Hazards and Protection.
Storage
Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Do not expose to air. Absorbs oxygen from the air and will darken upon exposure. Store protected from light. Store under an inert atmosphere.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use only in a well ventilated area. Minimize dust generation and accumulation. Do not breathe dust, vapor, mist, or gas. Do not get in eyes, on skin, or on clothing. Do not ingest or inhale. Store protected from light. Handle under an inert atmosphere. Store protected from air.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles 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
A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.
Small spills/leaks
Vacuum or sweep up material and place into a suitable disposal container. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Provide ventilation. Place under an inert atmosphere.
Stability
Stable under normal temperatures and pressures. May discolor on exposure to air. Air sensitive Light sensitive.
Incompatibilities
Oxidizing agents, bases, acid chlorides, potassium permanganate, acid anhydrides, alkalies, iron salts, antipyrine, iodine, air, camphor, menthol, ammonium hydroxide.
Decomposition
Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide.

Fire.
Flash Point,°C
164
Upper exp. limit, %
10.8
Lower exp. limit, %
1.7
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Extinguishing media: Use extinguishing media most appropriate for the surrounding fire. In case of fire use water spray, dry chemical, carbon dioxide, or appropriate foam.
Fire potential
This compound is probably combustible.
Hazards
Emits toxic vapors when heated.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.
Health
2
 
Flammability
0
 
 
Reactivity
0
 

Health.
Poison_Class
3
Exposure effects
May cause liver and kidney damage. Absorption into the body leads to the formation of methemoglobin which in sufficient concentrations causes cyanosis. Repeated exposure may cause sensitization dermatitis. May cause reproductive and fetal effects. Laboratory experiments have resulted in mutagenic effects. Pyrogallol has a tremendous affinity for oxygen of the blood and may cause death by respiratory failure.
   Ingestion
Causes gastrointestinal irritation with nausea, vomiting and diarrhea. May be harmful if swallowed. Rapidly absorbed from the gastrointestinal tract. Ingestion may cause weakness, muscular incoordination, fine tremors, loss of reflexes, convulsions and possible death from circulatory collapse.
   Inhalation
May cause methemoglobinemia, cyanosis, convulsions, tachycardia, dyspnea, and death. Causes severe irritation of upper respiratory tract with coughing, burns, breathing difficulty, and possible coma. May be harmful if inhaled. May be absorbed through the lungs.
   Skin
Causes severe skin irritation. May cause skin sensitization, an allergic reaction, which becomes evident upon re-exposure to this material. May be harmful if absorbed through the skin. Contact with skin may cause discoloration and eczema.
   Eyes
Causes moderate eye irritation.

First aid
 
   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 immediately. Induce vomiting by giving one teaspoon of Syrup of Ipecac.
   Inhalation
Get medical aid immediately. Remove from exposure to fresh air immediately. If breathing is difficult, give oxygen. DO NOT use mouth-to-mouth respiration. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask.
   Skin
Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.

Transport.
UN number
2928
Response guide
Hazard class
6.1
Packing Group
I; II
 
USCG CHRIS Code
PGA
 
HS Code
2907 29 00